Greetings everyone!

I hope to be joining in soon with a signature showing a 1st gen Camaro. I am looking at a private seller's awesome 69 Z28 with a pretty radical 406 sb. It claims about 640 hp (dyno'd at 540 rwhp) and has fully ported AFR 220s, 12.5:1 JE pistons, ported Wilson intake, and a solid roller with around 640/650 lift, modified Holley flowing over 1000cfm, 1 3/4 Hooker Super Comps, and 3" spintech mufflers, running a Muncie 4sp, 12 bolt 3.73 rear. That combo would seem to support the hp claims I think.

My question is this.

By lowering the compression to around 10.5 or 11.1 to run 91 octane (by switching the heads to from 62 or 64cc as they are now to the larger 72 or 76cc castings), how much hp am I expected to lose? I have read around 2-4% hp loss per point of compression decrease but I wasn't able to find much on the topic. Also, depending on the piston type (not sure if it's domed or flat top... guessing it is domed) will I have any detonation or other fuel "inefficiency" issues by changing the heads and lowering compression 1.5 to 2 points?

Thanks for the help in advance on this, and I hope to be updating my sig soon and joining in more.

Cheers!

wihtout more specifics on the cam it would be difficult to pinpoint. however, it sounds to me like that cam probably needs that amount of compression and that if you drop the compression the cam isnt going to want to run. you would then have mismatched the parts in the engine and taken the engine out of its optimum. I'm sure someone else with more knowledge and/or experience will chime in with their approximations

Leave the heads and change pistons. The engine would run much better/safer with small chambers, tight quench, and reverse dome/D-shaped pistons than it would with domes and large heads. The cam will most likely need changing for streetability also. I'm sure the duration is way too much for any less compression.

wihtout more specifics on the cam it would be difficult to pinpoint. however, it sounds to me like that cam probably needs that amount of compression and that if you drop the compression the cam isnt going to want to run. you would then have mismatched the parts in the engine and taken the engine out of its optimum. I'm sure someone else with more knowledge and/or experience will chime in with their approximations

I think I found the cam specs...

298/304 duration
.678/.636 lift

I know it's a big cam because it supposedly hit peak hp on the dyno at 8200 rpm.

Leave the heads and change pistons. The engine would run much better/safer with small chambers, tight quench, and reverse dome/D-shaped pistons than it would with domes and large heads. The cam will most likely need changing for streetability also. I'm sure the duration is way too much for any less compression.

This is what I was afraid of and trying to avoid doing - the engine was just built and has about 5-6 hours on it. Hmmm......

What about 11:1 or 11.5:1 and running a mix of 91 and 100 or 110 race fuel maybe??

Thanks for the quick replies you guys. I am going to see the engine builder in the next 1-2 days but wanted to bounce these questions off you all first.

I'm assuming advertised duration and 106/102 specs.

If you went flat-tops, it would run on pump gas. If you mix C-116, it will run like it sits. To each his own here for sure, but that cam is about right for me on the street. Bet it is just plain nasty. I can't see peak at 8200 though. Maybe 7200

Changing the compression on that kind of motor would be like sucking the life out of it. Cylinder pressure is what makes power.

Everthing on that thing appears to be built around high compression...cam, heads, pistons, intake, etc. You'd just be buying a block, heads, and part of the rotating assembly...everything else gets thrown away for it to work right on 91. It sounds like alot of time and effort got put into it (if it really was dyno'd), and you'd be screwing it all up.

My vote is to first run of 50/50 mix of race and pump fuel and run it for a while. If it costs too much, change all that stuff later OR sell the entire motor and buy something more like what you want. Anyway, I'd run it like it is for now.

OR....convert to E85 fuel like I did. Is that fuel available in your area?

Greetings everyone!

I hope to be joining in soon with a signature showing a 1st gen Camaro. I am looking at a private seller's awesome 69 Z28 with a pretty radical 406 sb. It claims about 640 hp (dyno'd at 540 rwhp) and has fully ported AFR 220s, 12.5:1 JE pistons, ported Wilson intake, and a solid roller with around 640/650 lift, modified Holley flowing over 1000cfm, 1 3/4 Hooker Super Comps, and 3" spintech mufflers, running a Muncie 4sp, 12 bolt 3.73 rear. That combo would seem to support the hp claims I think.

My question is this.

By lowering the compression to around 10.5 or 11.1 to run 91 octane (by switching the heads to from 62 or 64cc as they are now to the larger 72 or 76cc castings), how much hp am I expected to lose? I have read around 2-4% hp loss per point of compression decrease but I wasn't able to find much on the topic. Also, depending on the piston type (not sure if it's domed or flat top... guessing it is domed) will I have any detonation or other fuel "inefficiency" issues by changing the heads and lowering compression 1.5 to 2 points?

Thanks for the help in advance on this, and I hope to be updating my sig soon and joining in more.

Cheers!

Is this car at a dealer in Northern California? If it's the one I'm thinking of, that car looks awesome. When I lived in that area, I would get race gas from Sears Point.

OR....convert to E85 fuel like I did. Is that fuel available in your area?

I just researched quick and it looks like the only public e85 station ( out of 4 in Calif) is in San Diego. There is supposed to be one built in Madera in late 2006, but that isn't close to me either (I'm in Nor Cal).

Maybe down the road though.....

Is this car at a dealer in Northern California? If it's the one I'm thinking of, that car looks awesome. When I lived in that area, I would get race gas from Sears Point.

It was at Kassabian Motors in Dublin for about 2 months up until recently when the owner pulled it from their showroom - they had it marked up waaay too much and didn't even know how to drive the thing around the block. It was sad. I am now negotiating directly with the owner for a much better price. Yes, it is a helluva car and my only issue is the race fuel. I just would like to drive it more often. 100 octane is avail for about $6.75/gallon a few miles from where I am at a 76 station.

I just researched quick and it looks like the only public e85 station ( out of 4 in Calif) is in San Diego. There is supposed to be one built in Madera in late 2006, but that isn't close to me either (I'm in Nor Cal).

Maybe down the road though.....



It was at Kassabian Motors in Dublin for about 2 months up until recently when the owner pulled it from their showroom - they had it marked up waaay too much and didn't even know how to drive the thing around the block. It was sad. I am now negotiating directly with the owner for a much better price. Yes, it is a helluva car and my only issue is the race fuel. I just would like to drive it more often. 100 octane is avail for about $6.75/gallon a few miles from where I am at a 76 station.

Yep, that's the one. It was blue if I recall. Looks like it was done right from the pics. Good luck on the purchase, I hope it works out for you.

I don't know if a water/alcohol injection kit will allow it to run on 92 octane or not, but you just might look into it as a way to run it if possible?

pdq67

Changing the compression on that kind of motor would be like sucking the life out of it. Cylinder pressure is what makes power.

Everthing on that thing appears to be built around high compression...cam, heads, pistons, intake, etc. You'd just be buying a block, heads, and part of the rotating assembly...everything else gets thrown away for it to work right on 91. It sounds like alot of time and effort got put into it (if it really was dyno'd), and you'd be screwing it all up.

My vote is to first run of 50/50 mix of race and pump fuel and run it for a while. If it costs too much, change all that stuff later OR sell the entire motor and buy something more like what you want. Anyway, I'd run it like it is for now.

I used to run a 50/50 mix of 92 and 108 octane years ago on a 11.5:1 iron headed 406 sb and that seemed to be about the limit. You think 50/50 on this thing will be okay and not cause too much detonation? I may have to back off the timing a little maybe huh? That actually might be doable if it works...

Yep, that's the one. It was blue if I recall. Looks like it was done right from the pics. Good luck on the purchase, I hope it works out for you.

Yeah it is a really clean car done right. Has all the right parts and is a really clean Pro Touring car - Baers, DSE and Hotchkis suspension, and a stock looking interior. Price seems good too... hopefully I can make this work. Thanks for the kind words.

I don't know if a water/alcohol injection kit will allow it to run on 92 octane or not, but you just might look into it as a way to run it if possible?

pdq67

Hmm... I don't know anything about that really, but it's worth researching.. thanks for the idea.

How about getting all the specs and run the DCR program on it and see if pump gas is doable. Tody's 92 octane is like the old 97 octane.

How about getting all the specs and run the DCR program on it and see if pump gas is doable. Tody's 92 octane is like the old 97 octane.

Forgive me - I don't know what the DCR program is or where to get it. Help?

And I think 91 is the highest pump gas avail around here.

thx

check out these two dynamic compression ratio calcualtors

http://www.rbracing-rsr.com/comprAdvHD.htm

http://members.uia.net/pkelley2/DynamicCR.html

DCR = Dynamic Compression Ratio, the second link provides a pretty good explanation, but essentially it calculates where the piston is in its stroke when the intake valve closes and gives you a more accurate idea of the possibility of running on pump gas.

you also want to consider your quench. quench is the distance from the top of the piston at TDC to the top of the head gasket/bottom of the head. this should be between .035 and .045 and closer to .035 if possible.

Also the first link provides a variable for altitude, I too am at altitude and 91 octane is all that is available, however my theory is that because there is less oxygen at higher elevation our engines are less prone to detonation and therefore we can run a slightly lower octane fuel. I equate the 91 I have here with the 93 I had in Florida.

Fwiw, I think I've read where SONOCO 260 which was the BEST pump gas back then and was used in the 12.5 CR. 427 L-88 and 13.5 CR. MOPAR 426 Max Wedge Ramcharger engines was only like 97 or so octane!

I do know that E85 will be like 105 to 107 octane here in the midwest which I figure is good for up to 13.5 to 1 CR., but finding the darn stuff outside the midwest where we make it is HARD!!

But look how big those two engines cams were and how much cylinder pressure they bled off down low...

pdq67

DWG, This won't be a daily driver right? Hobby car correct, maybe a 1000 miles a year for fun.
If so, I would leave it like it is, as stated by others.
Mine needs race gas too, appox every 6 month I get a new 55 gal drum delivered to my house and pump it out as needed.
My dynamic compression with boost figured in, is over 14 to 1. For the street I mix about 60/40, VP103 unleaded with 91 with a little less timing. At the track almost 100% VP.
Price per gal or miles per gal, doesn't really matter to me. It's the FUN per mile that counts most!

check out these two dynamic compression ratio calcualtors

http://www.rbracing-rsr.com/comprAdvHD.htm

http://members.uia.net/pkelley2/DynamicCR.html

DCR = Dynamic Compression Ratio, the second link provides a pretty good explanation, but essentially it calculates where the piston is in its stroke when the intake valve closes and gives you a more accurate idea of the possibility of running on pump gas.

you also want to consider your quench. quench is the distance from the top of the piston at TDC to the top of the head gasket/bottom of the head. this should be between .035 and .045 and closer to .035 if possible.

Also the first link provides a variable for altitude, I too am at altitude and 91 octane is all that is available, however my theory is that because there is less oxygen at higher elevation our engines are less prone to detonation and therefore we can run a slightly lower octane fuel. I equate the 91 I have here with the 93 I had in Florida.

Thanks for posting the calc and info link. I think I have every number needed except for "Inlet Valve Closes ABDC"... where can I get that? I don't have the cam card if that's where it's supposed to be - I just have the duration/lift numbers on a spec sheet for the carb mods. Man, there is so much I don't know!



Fwiw, I think I've read where SONOCO 260 which was the BEST pump gas back then and was used in the 12.5 CR. 427 L-88 and 13.5 CR. MOPAR 426 Max Wedge Ramcharger engines was only like 97 or so octane!

I do know that E85 will be like 105 to 107 octane here in the midwest which I figure is good for up to 13.5 to 1 CR., but finding the darn stuff outside the midwest where we make it is HARD!!

But look how big those two engines cams were and how much cylinder pressure they bled off down low...

pdq67

Damn, we need some E85 here in Calif soon!

DWG, This won't be a daily driver right? Hobby car correct, maybe a 1000 miles a year for fun.
If so, I would leave it like it is, as stated by others.
Mine needs race gas too, appox every 6 month I get a new 55 gal drum delivered to my house and pump it out as needed.
My dynamic compression with boost figured in, is over 14 to 1. For the street I mix about 60/40, VP103 unleaded with 91 with a little less timing. At the track almost 100% VP.
Price per gal or miles per gal, doesn't really matter to me. It's the FUN per mile that counts most!

Correct, this will be a weekend and once in awhile weekday/night car, although I would like to drive it some distances once in awhile (maybe 80-100 miles one way). Not sure if that's possible though but that's why I'm looking into it here...

I think you may be right about this cuz I don't want to compromise a well-configured engine that runs like crazy... and it gets up there and goes... altho not quite as much as your crazy ride I'm sure!

I actually priced a 55 gal drum of 100 the other day at about $360, so if I can get it to mix with 91 around 50/50 I can probably live with that. I am just trying to balance driving it more often that just a day or 2 per week for a few miles. I really want to cruise as much as possible in it and would be willing to sacrifice a little horsepower in order to do so. I wish it had a pump gas 502 in it - easy to make 600+ hp with that!

Fun per mile is quality. :hurray:

Thanks for posting the calc and info link. I think I have every number needed except for "Inlet Valve Closes ABDC"... where can I get that? I don't have the cam card if that's where it's supposed to be - I just have the duration/lift numbers on a spec sheet for the carb mods. Man, there is so much I don't know!


Click on the second link. Towards the bottom of the page is the Pat Kelly DCR program. Plug the duration numbers in and it will spit out the closing angle to use. It is more comprehensive program than the first link.

Water injection and a bit less cam. Possible, thicker head gaskets to drop some compression. Better yet, get all build receipts for engine (if possible) and sell it complete...Put in a crate motor.
Hurry up and buy the darn thing!:thumbsup:

Click on the second link. Towards the bottom of the page is the Pat Kelly DCR program. Plug the duration numbers in and it will spit out the closing angle to use. It is more comprehensive program than the first link.

I just tried that but I don't know the lobe separation or the intake lobe centerline. Damn.....

Water injection and a bit less cam. Possible, thicker head gaskets to drop some compression. Better yet, get all build receipts for engine (if possible) and sell it complete...Put in a crate motor.
Hurry up and buy the darn thing!:thumbsup:

I am meeting the engine builder tmrw morning and hopefully he has more info on it since it is so new. I am going to print out this whole damn thread with all of the ideas and bounce them all of him. This guy builds some pretty crazy race motors around here from what I hear and he supposedly has a good reputation.

The idea to sell the motor and then drop in a big block has crossed my mind more than once. I will be getting something soon, and this one is at the top of my list right now. :thumbsup:

The only problem with E85 is the alcohol content which means dropped gas mileage and the adjustment of the carb to handle the alcohol content.

Changing the compression on that kind of motor would be like sucking the life out of it. Cylinder pressure is what makes power.

Everthing on that thing appears to be built around high compression...cam, heads, pistons, intake, etc. You'd just be buying a block, heads, and part of the rotating assembly...everything else gets thrown away for it to work right on 91. It sounds like alot of time and effort got put into it (if it really was dyno'd), and you'd be screwing it all up.

My vote is to first run of 50/50 mix of race and pump fuel and run it for a while. If it costs too much, change all that stuff later OR sell the entire motor and buy something more like what you want. Anyway, I'd run it like it is for now.

Thanks for the feedback.... do you think I would have to back the timing off a bit to go with the 50/50 mix? I can swallow the cost of the race fuel as long as it isn't 100% race fuel. I need a LITTLE real world streetability here ya know?

Just guessing is all after running your cam through D2k at 298/304 and just .650" lift on both sides at both 114/114 and 114/108 it ranges from 77 ICA at 108 and 83 ICA at 114!

Doing it again at 108/108 gave me 77 ICA again.

So I figure you should use 77 to 83 in a DCR program for starters until you get more accurate LCA/ICA numbers.

As always, hope this helps.

pdq67

Thanks for the feedback.... do you think I would have to back the timing off a bit to go with the 50/50 mix? I can swallow the cost of the race fuel as long as it isn't 100% race fuel. I need a LITTLE real world streetability here ya know?

It certainly wouldn't hurt.

A while back I ran my motor with 12.5:1 and a relatively small cam...245PSI cylinder pressure! It was like a diesel! Even then, I ran a 30/70 mix (30% 110 octane) and backed the timing down to 30 or 32 and ran it on the street. Worked out just fine, never pinged, and saved a bunch of dough on gas. A little 110 goes a long way!

Putting a thicker head gasket in to drop compression is NOT a good idea. You would be better off with higher compression and a better quench. I am not sure I understand the build of the car? If it is a "pro touring" car, why would you build a "drag race" engine for it? The car will not perform well at the track due to the suspension and short, stiff sidewalls. Doesn't soun't like much fun to me if you can't drive it on the street or have to stay within 50 miles of your drum of fuel. Maybe you can build a trailer to haul your race gas around with you? Seriously, think this thing through before you buy. I have been there and done that and running race gas or having to mix gas is a pain in the rear. If you don't mind staying in town or trailering the car, then it's ok. I personally drive my cars on long trips (no trailer) so, they have to run on pump gas.

You lose your whole advantage if you have to pull out timing and play the other games. Maybe the guy will sell you the car less the engine? Then you can take the money you saved and build or buy another engine that is more fit for street use.

Water injection would certainly help and might be all you need but, you will have to pay attention and make sure you never run out of water/alky or you will be stranded.

Just some things to think about.

Just guessing is all after running your cam through D2k at 298/304 and just .650" lift on both sides at both 114/114 and 114/108 it ranges from 77 ICA at 108 and 83 ICA at 114!

Doing it again at 108/108 gave me 77 ICA again.

So I figure you should use 77 to 83 in a DCR program for starters until you get more accurate LCA/ICA numbers.

As always, hope this helps.

pdq67

Thank you - yes that def helps. I ran a few diff scenarios and the DCR spit out a range of 8.18 to 8.81 static CR. I need to do a little more reading to see what that actually translates to! :)

It certainly wouldn't hurt.

A while back I ran my motor with 12.5:1 and a relatively small cam...245PSI cylinder pressure! It was like a diesel! Even then, I ran a 30/70 mix (30% 110 octane) and backed the timing down to 30 or 32 and ran it on the street. Worked out just fine, never pinged, and saved a bunch of dough on gas. A little 110 goes a long way!

It def is an option to try it that way, but I need to seriously think about if I want to be playing the mixing gas game and backing off full timing. I did run the 108/92 mix once and it can be kind of a hassle sometimes.

Putting a thicker head gasket in to drop compression is NOT a good idea. You would be better off with higher compression and a better quench. I am not sure I understand the build of the car? If it is a "pro touring" car, why would you build a "drag race" engine for it? The car will not perform well at the track due to the suspension and short, stiff sidewalls. Doesn't soun't like much fun to me if you can't drive it on the street or have to stay within 50 miles of your drum of fuel. Maybe you can build a trailer to haul your race gas around with you? Seriously, think this thing through before you buy. I have been there and done that and running race gas or having to mix gas is a pain in the rear. If you don't mind staying in town or trailering the car, then it's ok. I personally drive my cars on long trips (no trailer) so, they have to run on pump gas.

You lose your whole advantage if you have to pull out timing and play the other games. Maybe the guy will sell you the car less the engine? Then you can take the money you saved and build or buy another engine that is more fit for street use.

Water injection would certainly help and might be all you need but, you will have to pay attention and make sure you never run out of water/alky or you will be stranded.

Just some things to think about.

I think you might have nailed it here. You are right - this car really is half Pro Touring and half Drag Race or Pro Street... I like the combo but you have to question the practicality of it vs. my usage intention. I doubt he will sell me the car less motor, but it certainly is a discussion I can have with him. As I said before I have run 108/92 mix before but back then I didn't take the car out of town, which is what I would like to do this time. I may need to scrap this motor in favor of a big block or just find a different car. I will see what the engine builder says about water injection or some other ideas today to see if this whole thing is feasible for me.

thanks for chiming in.

I'm with Royce on this. It sounds like you have a mismatched engine for the rest of the package (and intended useage)...one thats probably not going to be too happy about low speed cruising. It probably has a solid roller cam in it, which are not known for having too great of a life at "street" rpms. Plus, what would a setup like that get...about 3mpg? ;) Whats that, about 300-350 miles per 55 gallon drum of race fuel (assuming a 50/50 mix)?
If you really like and want the car, it sounds like you would be better off selling the engine out of it, and taking that money and building something more appropriate for what you want to do with it. You can still build enough power to get yourself in lots of trouble on pump gas ;)

I'm with Royce on this. It sounds like you have a mismatched engine for the rest of the package (and intended useage)...one thats probably not going to be too happy about low speed cruising. It probably has a solid roller cam in it, which are not known for having too great of a life at "street" rpms. Plus, what would a setup like that get...about 3mpg? ;) Whats that, about 300-350 miles per 55 gallon drum of race fuel (assuming a 50/50 mix)?
If you really like and want the car, it sounds like you would be better off selling the engine out of it, and taking that money and building something more appropriate for what you want to do with it. You can still build enough power to get yourself in lots of trouble on pump gas ;)

The motor makes this particular car what it is. I don't have a pic of it, but it's just dripping with attitude. A pro-tour style car with a radical small block isn't everyone's cup of tea, but it's one of the coolest cars I've seen available in quite awhile. But maybe it's just me.

I'm with Royce on this. It sounds like you have a mismatched engine for the rest of the package (and intended useage)...one thats probably not going to be too happy about low speed cruising. It probably has a solid roller cam in it, which are not known for having too great of a life at "street" rpms. Plus, what would a setup like that get...about 3mpg? ;) Whats that, about 300-350 miles per 55 gallon drum of race fuel (assuming a 50/50 mix)?
If you really like and want the car, it sounds like you would be better off selling the engine out of it, and taking that money and building something more appropriate for what you want to do with it. You can still build enough power to get yourself in lots of trouble on pump gas ;)

Yes it's a solid roller. And it may be more suitable for my intentions to switch it out for a similar sized hydraulic roller and flat tops to bring the compression down to 10.5 or 11:1. This motor has great internals, great heads and is just a bit over the edge for frequent street trips IMO...

The motor makes this particular car what it is. I don't have a pic of it, but it's just dripping with attitude. A pro-tour style car with a radical small block isn't everyone's cup of tea, but it's one of the coolest cars I've seen available in quite awhile. But maybe it's just me.

This is what's tough! It is NOT like every other Pro Touring 67-69 Camaro, and that is what makes it unique. My thought is to buy it as is and drive it for awhile and see how it goes.... then if I really want to drive it on trips, I can change the cam and pistons and lose a little bit of power.... it's not like it will hook on the street with 640hp or 550-575hp anyway with the 17's!

I just met with the engine builder today and they run a nice operation. To change to hyd roller cam and JE flat tops including parts and labor they quoted me about $4500 - including removing and reinstalling the engine. It includes new rings, hone block, balancing, valve springs, pushrods, gaskets, etc.

It's a good plan B i guess.....

4500 to do that seems a bit steep to me. you can buy a decent crate motor for not much more and then sell the motor in the car.

http://motors.search.ebay.com/sbc_Complete-Engines_W0QQcatrefZC2QQfromZR40QQfsooZ1QQfsopZ1QQs acatZ33615QQsamcmZ6028 for a taste of what is out there. one of the last on the page is a 550hp/550tq 383 for 6k. there are MANY good engines out there for less than what the shop wants to charge you for a cam and piston change.

Yes it's a solid roller. And it may be more suitable for my intentions to switch it out for a similar sized hydraulic roller and flat tops to bring the compression down to 10.5 or 11:1. This motor has great internals, great heads and is just a bit over the edge for frequent street trips IMO...



This is what's tough! It is NOT like every other Pro Touring 67-69 Camaro, and that is what makes it unique. My thought is to buy it as is and drive it for awhile and see how it goes.... then if I really want to drive it on trips, I can change the cam and pistons and lose a little bit of power.... it's not like it will hook on the street with 640hp or 550-575hp anyway with the 17's!

I just met with the engine builder today and they run a nice operation. To change to hyd roller cam and JE flat tops including parts and labor they quoted me about $4500 - including removing and reinstalling the engine. It includes new rings, hone block, balancing, valve springs, pushrods, gaskets, etc.

It's a good plan B i guess.....


Out of curiosity, who's the engine builder? Is it Top of the Hill or Blackstone? They're the only ones in the area I can think of that would build something like that.

DWG, The final word is yours, it's your money. I honestly don;t get it though. As you already mentioned the suspension and tires on the car can't use the HP anyway. We used to call those "Cat cars" because they like to try to climb poles and trees.

It's a toy and it's for your enjoyment if burning rubber and trailering the car is fun to you , then you should do it. The mere fact you are asking the questions that you are tells me you are not really "sure". I have no idea how much you are planning to spend but, I know it can't be cheap. Why would anyone spend big money on a car that is complete and then not get exactly what you want. If you are getting a great deal on the car then that's a different story.

Sit down with the wife and family (if that applies) and figure out how the car will "actually" be used. Once you know the TRUE plans for the car then make a decision. Nobody on this board can answer the questions for you.

You say you would swap the cam and pistons at a later date if needed. The problem with that is, you will then have heads that are way to big for the application. We haven't even discussed the rest of the car and what it is set up for (gears, tranny, etc..). What does it have for induction (carb fuel injected)? What about intake manifold? If you really like the car and want to drive it, I would suggest you try to sell off the engine, work on getting a buyer even before you buy the car. A well matched pump gas engine will run with that race engine the car has (cause if you can't hook, all the HP does you no good).

Out of curiosity, who's the engine builder? Is it Top of the Hill or Blackstone? They're the only ones in the area I can think of that would build something like that.

It is Dave's Engine Machine in Newark. He does some pretty wicked stuff down there. I have seen a couple really nice GM cars around with his engines lately. Heard of him?

The motor makes this particular car what it is. I don't have a pic of it, but it's just dripping with attitude. A pro-tour style car with a radical small block isn't everyone's cup of tea, but it's one of the coolest cars I've seen available in quite awhile. But maybe it's just me.

I can agree with that...if it is a trailer queen or a hanger queen. I thought the whole idea behind this pro-touring thing was a one that was driveable and handles killer and all that. I just don't see how it would be cool to own a car that you cant drive more than 50 miles from your drum of race gas. Maybe its just me, but I like to drive my stuff.
Without knowing the exact specs of the engine, its hard to make any recommendations on how to tone it down a notch or 2. But like I said, you can still build big, stupid power on pump gas, and drive anywhere without fear of not being able to get fuel for it.

DWG, The final word is yours, it's your money. I honestly don;t get it though. As you already mentioned the suspension and tires on the car can't use the HP anyway. We used to call those "Cat cars" because they like to try to climb poles and trees.

It's a toy and it's for your enjoyment if burning rubber and trailering the car is fun to you , then you should do it. The mere fact you are asking the questions that you are tells me you are not really "sure". I have no idea how much you are planning to spend but, I know it can't be cheap. Why would anyone spend big money on a car that is complete and then not get exactly what you want. If you are getting a great deal on the car then that's a different story.

Sit down with the wife and family (if that applies) and figure out how the car will "actually" be used. Once you know the TRUE plans for the car then make a decision. Nobody on this board can answer the questions for you.

You say you would swap the cam and pistons at a later date if needed. The problem with that is, you will then have heads that are way to big for the application. We haven't even discussed the rest of the car and what it is set up for (gears, tranny, etc..). What does it have for induction (carb fuel injected)? What about intake manifold? If you really like the car and want to drive it, I would suggest you try to sell off the engine, work on getting a buyer even before you buy the car. A well matched pump gas engine will run with that race engine the car has (cause if you can't hook, all the HP does you no good).

There will be no trailer and I can handle some race gas I think. Just call all of this thinking out loud I guess. You guys all have cars that go... it's been awhile for me, and last time I was involved with a hot rod I had no money and mismatched parts. Now I can buy something the way I want it, or change it to the way I want it. I like Pro Street, but I really like Pro Touring, so maybe a little of both is actually what I want. This thing is damn close to what I want.

Here is the setup (M21 4 spd, 12 bolt 3.73, fully ported AFR 220s, ported Wilson intake, worked Holley carb flowing 1000+ cfm, 298/304 adv dur, .678/.636 lift, 6" Carillo rods, 12.5:1 JE domed pistons, Super Comp 1 3/4" headers, dual 3" exhaust with Spintech mufflers)

Has 17" torque thrusts all around with Nitto drag radials.

We haven't gotten into how long the M21 will last with all this power.

No wife and no family. You are right about making the decision on this car - the post started out technical but has turned into what I really want. I appreciate everyone's insight as it does really help, but it's on me in the end.

Thanks again.

Have you been over to Larry C's great "Pro-Touring" site yet??

I assume you have.

pdq67

It is Dave's Engine Machine in Newark. He does some pretty wicked stuff down there. I have seen a couple really nice GM cars around with his engines lately. Heard of him?

I haven't heard of him. But, I moved from the area on '03. The price seems about right for quality work in Northern California.

Have you been over to Larry C's great "Pro-Touring" site yet??

I assume you have.

pdq67

Yep, have it bookmarked and I check it every other day probably. That one as well as lateral-g.net.....


I haven't heard of him. But, I moved from the area on '03. The price seems about right for quality work in Northern California.

They do use the best parts money can buy on everything. Who did you have work done by when you lived around here?

Yep, have it bookmarked and I check it every other day probably. That one as well as lateral-g.net.....

They do use the best parts money can buy on everything. Who did you have work done by when you lived around here?

Craig Hill at Top of the Hill Performance. http://topofthehillpc.com. That's my old 5.0 Mustang race car on the website. They acquired Techcraft racing engines a few years back and are now a full service engine/machine shop. Their new shop out in Livermore is unbelievable. If you're looking for quality, that's the place to go.

Craig Hill at Top of the Hill Performance. http://topofthehillpc.com. That's my old 5.0 Mustang race car on the website. They acquired Techcraft racing engines a few years back and are now a full service engine/machine shop. Their new shop out in Livermore is unbelievable. If you're looking for quality, that's the place to go.

Thanks Neil. I just emailed Craig to talk about pricing for switching the pistons/cam out. I told him you sent me.

Thanks for the help.

Thanks Neil. I just emailed Craig to talk about pricing for switching the pistons/cam out. I told him you sent me.

Thanks for the help.

You're welcome. Craig always exceeded my expectations. I haven't talked to him in awhile. Tell him I said hello.

Hey, just to help confuse you more- don't let that cam scare you-- I'd just swap pistons since this sounds like a "weekend car" like most of ours. $600 for a new set of j&e's, plus the teardown and re-assembly, it shouldnt' cost you that much to get down to 11:1 or a hair less which should be fine on 93 (mine is and it is right at 10.9-11:1. Check the stats on my motor in the pro-touring garage link in my signature below-- I've driven it a lot this year, 600 miles round trip to one show, 400 to another. It will do 2 round trips of a couple hours each way to Rhinebeck NY from CT next weekend for a Goodguys show. With the overdrive I managed a best of 15.7mpg highway and I manage 10-12mpg in local driving. (ok, 8mpg beating the snot out of it on one tank!)

My previous 350 had heads and a cam similar in size to what you are looking at and I ran it until this spring and logged over 13000 miles on it. You can tolerate a lot of cam and big volume heads with a manual tranny and low gears. So they can be driven just fine with a big mech. roller, and the power is what makes it so much fun!

Just make sure the motor has lifters with a good oiling system, like Crower's with the pressurized pin oiling. Also, good valve springs are a must, AFR's stock springs are cheap brazilian units.

-Dan

Hey, just to help confuse you more- don't let that cam scare you-- I'd just swap pistons since this sounds like a "weekend car" like most of ours. $600 for a new set of j&e's, plus the teardown and re-assembly, it shouldnt' cost you that much to get down to 11:1 or a hair less which should be fine on 93 (mine is and it is right at 10.9-11:1. Check the stats on my motor in the pro-touring garage link in my signature below-- I've driven it a lot this year, 600 miles round trip to one show, 400 to another. It will do 2 round trips of a couple hours each way to Rhinebeck NY from CT next weekend for a Goodguys show. With the overdrive I managed a best of 15.7mpg highway and I manage 10-12mpg in local driving. (ok, 8mpg beating the snot out of it on one tank!)

My previous 350 had heads and a cam similar in size to what you are looking at and I ran it until this spring and logged over 13000 miles on it. You can tolerate a lot of cam and big volume heads with a manual tranny and low gears. So they can be driven just fine with a big mech. roller, and the power is what makes it so much fun!

Just make sure the motor has lifters with a good oiling system, like Crower's with the pressurized pin oiling. Also, good valve springs are a must, AFR's stock springs are cheap brazilian units.

-Dan


I'm glad you chimed in because your setup is very similar to this 406 I am looking at. Awesome car you have there by the way. :thumbsup: Must be a blast to drive.
You have an even bigger cam that this one, and I see it's a solid roller. That is one of the things I would like to change to make it almost zero maintenance (theoretically) so I don't have to monitor and adjust valves often. How often do you have to do that? I am not as handy as most of you on this board so I need to be careful with what I get into. I am willing and able to do some basic/simple things, but I really want as low-maintenance as possible for a ton of power.

Those mpg numbers are damn good for that much power.. of course the 6 speed helps. This one has a M20/21 4 speed and 3.73s so the 5 or 6 speed conversion is something I could see in the cards very easily sooner or later. I am not convinced the Muncie can handle this much power for a prolonged period of time.

I have been told I will not lose that much power (but definitely some revving ability) by going from solid roller to a similar sized hydraulic roller. This is what I would like to do, but it is quite a bit of money to pull the motor just for a piston swap. But if that's what it takes then.....

I am gathering a couple other quotes from reputable shops in the area now to get some prices.

Thanks again for your input - sweet Camaro you have there.

Thanks,

Unfortunatly You could see a pretty significant power loss going hydraulic roller since the ramp angles are much less aggressive than a mechanical roller-- to give you an idea, my engine builder figured my motor would be 550-560hp on a hyd roller. (Hence why I did what I did- I'm greedy!) But it is less maintanance.

With the Jessel rockers I've seen no lash change. I checked them a few times being that everything was fresh, but for the most part I set them in the spring, check them once in August, then back them off for the winter once the snow flies. If you hear any roller noise then always check them, we caught a friend's motor just in time that had a roller lifter giving up, the lash increases a bunch and you can hear the rocker rattle. (those were with the Comp Cams lifters with the oil grooves, I've had no problems with the pressurized oiling ones with the small feed hole).

As far as compression, the old rule of thumb was 2-3% gain in hp for every point of compression you add. (so going from 12.5:1 to 11:1 should cost you a 3%-4.5% power loss.) but that is just a rule of thumb, every motor is different.

Good luck, feel free to yell if I can help at all. -Dan

Let me throw this out here for everybody to chew on!!

Please consider adding thick enough headgaskets, even stacking them, to get your CR. down where you want it b/c I think that I have read that once you go past .100" AND ABOVE quench, it begins to not matter b/c there becomes enough space in the quench regions so the fuel/air mixture back in the tight areas can start to burn like all the rest in the chamber at fire-off. Which negates' detonation due to quench not being good.

Onna the mag's years ago took a 100 percent open chamber headed MOPAR motor that was like 12.5 to 1 and kept adding headgaskets to see just how much power was lost if everything else was held the same and they came up with the about 4 percent drop for every 1.0 point drop in CR.

The ONLY thing they didn't do was run pump gas in itAND that was only b/c they were araid of rattling it to death at 12.5 to 1CR. AND they said as much in the article.

Anybody know of any completely open chamber headed, high compressioned engine combinations that have proved all this??

The article went on to say that the big cammed motor ran fine in a low CR. mode, but that it was just "soft" was all throughout the rpm range b/c it lacked the CR. to be "crisp" like it was made to be!! Soft to the tune of, if I recall right, 440hp or vs a bunch more in the high CR. mode.

pdq67

PS., I can did the old mag out of my many boxes if wanted, but it will take some time!!

I would sell the engine and buy a new GM Crate Engine. There is a good listing of them at Summit Racing com. They come in many different hp ranges and they all run on 93 octaine. I have one in my 69Z with approx 430hp and it runs like a bandit.
Schoon

How's this thread coming along?

pdq67

How's this thread coming along?

pdq67

I have been pondering the Camaro in question while looking at other cars locally and from distance. I called to followup with this guy last night and he just made a deal to sell the existing high compression motor for 8k to somone, so he is pulling that out and said he ordered a mild 330 hp 350 crate motor. He now said he will sell the car with the new crate motor for $46k?? Hmm.... But would let the car go with no motor for $36k. I am going to meet him again today and talk further. I think he's just frustrated.... it's a killer car and that would allow me to choose my motor but I think 36k is a little high. If he will come down a little then maybe.....

Thanks for everyone's insight and ideas on the high compression topic that initiated this thread. This forum is fantastic.