its a 2 bolt block

since it is a 2 bolt, i understand that the rpms should be kept below 6000 rpm.. so obviously thats where i want my power, well maybe a bit below

im looking for 500+ hp if it is possible.. but im going for MAX

streetability isnt a concern.. the car will be a max street/strip car, it will maybe see 100 miles a year street use.. its not my daily driver, im not concerned about having to buy race gas.. but it does have to be able to actually drive

personally i would like to get a comp cam 292 cam, or the 305 magnum series (hydraulic is what i was looking at.. but a comparable solid cam is fine)

so tell me what you guys think on heads/intake/rotating assemblies

price is a factor here.. stick with the stuff that can be found in jegs/summit/sdpc books, im not looking to spend $3500 on a set of custom race heads

i do prefer dart/afr heads, and i generally dislike edelbrock stuff.. but if it will make the most power, its fine

not sure what tranny will be behind the engine, but its either going to be an m22 or a built th350 w/ 3500 stall

and just a question.. this block has a 2 piece rear main seal, correct? and is it possible to use a "383" crank to use a normal 350 flywheel/balancer?

2 bolt is better than 4 bolt on 400's

6000rpm limit :noway: I've been 7000 more than a few times :D

Stud the bottom end and maybe do a short fill on the block.
5.7 or 6" rods
Forged crank would be best, but a cast will live (3.75 or 3.8" stroke) Scat or Eagle will work
light weight forged pistons (weisco ?) Compression is up to you.
220cc or 230cc heads (steel is fine and cheaper...RHS is good IMO)
I would rather see a solid roller in there too.


Use the th350 and 3500 stall (4500 will be better for max performance)

400's a 2 peice seal

unless you get internal balance you can not use a 350 balancer or flywheel

383 crank is a 400 crank in a 350 (just one way to do it)


This is just my take on things.

I talked to a guy with a 69 Camaro at the drag strip that had run a 400 SBC the year before. It sounded like he drove the car during the week and raced it on most weekends. He said you can wind a stock crank to 6500, just not every weekend. he had switched to a 454 cuz the crank broke at the end of the last season. That might be where that type of input came from. I think the aftermarket cranks might hold up better,

Jeff

I talked to a guy with a 69 Camaro at the drag strip that had run a 400 SBC the year before. It sounded like he drove the car during the week and raced it on most weekends. He said you can wind a stock crank to 6500, just not every weekend. he had switched to a 454 cuz the crank broke at the end of the last season. That might be where that type of input came from. I think the aftermarket cranks might hold up better,

Jeff

probably, i just have a block sitting here, so everything is gonna be new!

2 bolt is better than 4 bolt on 400's

6000rpm limit :noway: I've been 7000 more than a few times :D

Stud the bottom end and maybe do a short fill on the block.
5.7 or 6" rods
Forged crank would be best, but a cast will live (3.75 or 3.8" stroke) Scat or Eagle will work
light weight forged pistons (weisco ?) Compression is up to you.
220cc or 230cc heads (steel is fine and cheaper...RHS is good IMO)
I would rather see a solid roller in there too.


Use the th350 and 3500 stall (4500 will be better for max performance)

400's a 2 peice seal

unless you get internal balance you can not use a 350 balancer or flywheel

383 crank is a 400 crank in a 350 (just one way to do it)


This is just my take on things.

thanks i was looking between 12.5 and 13.5:1 comp ratio

is it hard to turn these blocks into roller blocks? i hear it can be pretty costly in a 350 chevy

If it were mine and I wanted to cruise it and race it I would look at a set of AFR 210s or Dart 215 heads a soild roller cam with 260-270 dur at .050 and around .680 lift for all mule a 106 lobe sep for a small shot 110 lobe sep.Have the comp at 11.5 to 1 max for pump gas or higher if you want race fuel. Intake it seems the world products single plane does well with the big inch motors and for a carb 950hp or 1000 hp. use a header with 1 3/4 primary a set of magnaflow mufflers. In the rear a 4.10 gear with a 28'' tire and for the tranny a 4500-5500 rpm stall.:cool:
I would also make the motor internally bal. and use a 5.85 or 6.0 rod.

Why is 2 bolt block better than the 4 bolt in the 400 ?

Whats hard in using a roller cam The only thing you will have to do is set the cam shaft end play I have the comp cam tming cover it makes it very simple.

2 bolts have more meat around the main cap bolts.

roller in a non roller block...

roller cam, retro-fit lifters,cam button,and springs to match cam.

all thats needed.

Plus .100 longer valves.

roller in a non roller block...

roller cam, retro-fit lifters,cam button,and springs to match cam.

all thats needed.

Whats hard in using a roller cam The only thing you will have to do is set the cam shaft end play I have the comp cam tming cover it makes it very simple.

cool, thanks for the cam info.. now i have heard that roller cams dont sound as good at idle as hyd/solid cams do.. is this true?

If it were mine and I wanted to cruise it and race it I would look at a set of AFR 210s or Dart 215 heads a soild roller cam with 260-270 dur at .050 and around .680 lift for all mule a 106 lobe sep for a small shot 110 lobe sep.Have the comp at 11.5 to 1 max for pump gas or higher if you want race fuel. Intake it seems the world products single plane does well with the big inch motors and for a carb 950hp or 1000 hp. use a header with 1 3/4 primary a set of magnaflow mufflers. In the rear a 4.10 gear with a 28'' tire and for the tranny a 4500-5500 rpm stall.:cool:
I would also make the motor internally bal. and use a 5.85 or 6.0 rod.

thanks a bunch.. how much hp do you think that setup would have?

i was looking at the jegs book, and saw that they say their heads (canfield) with a 13.5:1 comp ratio made 620hp

that sounds great and something i would like to have

heres my deal, i like doing everything myself, but i dont really understand what to do when porting heads, so i would like something where i wont have to do that like grind stuff down

if i was running 13.5:1 comp with aluminum heads what octane could i get away with using? I was thinking of using a mix of race fuel and 93 octane.. what octane number would i need? I know it will be lower considering a high duration cam like you suggested would have a lot of bleed off

also im assuming piston to valve clearance wont be a problem?

actually im thinking of turning to alcohol.. its pretty cheap.. is the carb the only thing different when using it? (i will have different fuel lines so those dont matter) can a carb thats set up for alcohol run on gas too, or is it either one or the other?.. now that i think about it.. i probably cant run alcohol on the street.. huh, so i guess scratch that idea

Solid roller, you be the judge

http://i10.photobucket.com/albums/a130/Dougs68Camaro/th_DSCF0001-3.jpg (http://s10.photobucket.com/albums/a130/Dougs68Camaro/?action=view&current=DSCF0001-3.flv)

Solid roller, you be the judge

http://i10.photobucket.com/albums/a130/Dougs68Camaro/th_DSCF0001-3.jpg (http://s10.photobucket.com/albums/a130/Dougs68Camaro/?action=view&current=DSCF0001-3.flv)

it sounds more "hollow" than my hydraulic IMO

this is almost exactly what mine sounded like YouTube - Camaro 81 with 355 chevy

without the mufflers though

edit, although these sound great: YouTube - 1970 Camaro SS/RS 406 idle

YouTube - My 70 Camaro - roller 406 - idle and rev

if i could get one to sound like those i would have a never ending smile on my face

It has more of a growl to it, still has some lope, and way easier to hit 500+HP

If you are wanting around 600 hp I would step up to a set of dart cnc 227 heads I have a set of these out of the box on my 434 it makes around 640 to 650hp. in a 3400 lbs car on pump gas it will go 10.00s on motor. The canfield heads are ok I think you will be better off with a set of dart or afrs and for the fuel with that much comp I would run no less than 100 oct if you only drive it a couple hundred miles a year it wont be that bad on cost.

thanks.. so basically these dart heads are like a ported head.. so in a way i am buying ported heads that will need to work?

Yes the cnc 227s from dart will work out of the box. Just check the springs will work with the cam you decide to go with. You will be very happy but thay do cost a little more than a set of 215s.

DISCLAIMER: These are my opinions based on years of building, experimenting, destroying, etc... take it for that and make your own opinions :-)

400 SB Chev is one of the best "all-around" platforms created, it does however have a few caveats.

Yes, 2 bolt main is more desirable in almost all cases, it does have more iron in the cast around the main bearing journals. The 2 bolt main can be made to go into the 8500+ rpm range if you purchase splayed 4 bolt main caps for it and have it machined to accept them. Pretty costly to do so, but a great base if done.

6 inch rods and the 400 are like "peas and carrots", they just go together. Run short skirt pistons for this rod so they don't come very far out of the cylinder on the bottom of the stroke. Short skirts will have a slightly lower life span on the street due to wear increase from he lessened surface area covered with oil on the skirt itself. You may have to clearance the block depending on what rod you run, but the operation is not that hard.

Forged steel crank, don't skimp there. Standard grind for 400 is superb, you can stroke a tiny bit and only have minor clearance issues to machine for, but a factory GM 400 (non-bowtie or GM performance parts) can't handle much more stroke than stock.

Definitely pay the extra money at the machine shop to have the rotating assembly balanced internally. If you have a really good machine shop they can drill out the rod throws on the crank and really lessen the reciprocating weight, which is very very desirable if you plan to run this thing up, otherwise just go with the lightest rod you can afford that is up to the reqs for the compression ratio you desire.

Heads... stay away from camel humps unless you already have a really good set with hardened seats and guides already done in them (and cut out to 2.02s, a requirement for a good 400), otherwise you'll spend enough money getting them up to snuff that you could easily have purchased a good set of Darts and you'd still only have deck thickness that is only about 70% of the Darts. I actually really like the Dart Pro 1 for the 400 application. You can spend a lot of time getting the best piston top/combustion chamber combo for quench issues if you are going high compression so do your homework there, don't get a head with combustion chamber that is so tight and shrouds the valves so much the valves have flow issues (yes, you can buy heads that have this issue from the get go and can only be corrected by CNCing them and opening the chamber back up). If the Darts are out of your price range, I have actually built two small blocks now with sets of aluminum heads from "ProComp" an Australian company putting out what essentially is a "Pro 1" copy. Both of these small blocks have been running hard now for a couple seasons of Friday night fights and street dragging with no issues. I have heard of others who have had less success with them than I have so its kinda of a "up to you".

Intake, MAKE SURE IT FITS UNDER YOUR HOOD! LOL I can't tell you how many intakes I have purchased from people who bought them off eBay or something and didn't realize it wouldn't fit under their hood. Stay away from single planes if you are really looking for a low RPM launch, but if you plan to run up in the 3000+ range a lot go single plane (a good Victor, Vic Jr. or Team G work great here, but seriously, there are many many great options).

Camshaft, get the rest of your components picked, then call Crower's tech line and give them the specs (including head flow numbers) and Crower is awesome to simulate your engine and find the best grind for your desired RPM range.

I have a special place in my heart for 400s even though I have mostly been doing BBs lately, they are fantastic little motors. They DO NOT LIKE TO OVERHEAT, they are very susceptible to cylinder wall distortion when they are overheated, which will trash your new expensive pistons with the special oil rings grooves for the long rods!. I am sure by now you have heard of their "siamesed cyl walls" which is the cause for this heat intolerance.

Anyway, I ramble on.... hopefully some of my "opinions" here are useful to you!

-Adam

thanks, and they were useful

i will only be using the machine shop.. well to get the block machined, i will be purchasing and installing everything myself (except for cam bearings, my machine shop guy will put them in for $40.. including the bearing price.. a tool isnt much cheaper than that)

i am planning on getting the block bored 20 over.. thats all it needs, and they make the pistons for it.. should i get it sonic checked for this amount? the guy who sold me the block told me it would need bored 20 over to remove the ring groove.. but could i just get it honed instead and use stock sized pistons?

after looking at cams, i kinda like this one: http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=310&sb=2

yes a solid roller cam.. if i did purchase the dart pro1 230cc or the cnc heads.. would this be a good cam?

i dont really have a desired rpm range, im just looking for a beast of an engine.. even though i doubt it will see more than 6500rpm.. i would like to get the 4 bolt caps put on it.. how much would that cost for a machine shop to do? i dont like the idea of drilling a block, i would be afraid of messing it up

most of the cranks i am looking at are internally balanced.. so i can use a 350 balancer/flywheel.. does anything else have to be balanced?

i already had a weiand xcellerator (hi rise) on my old engine, and it fit under the stock z28 hood.. im not sure how much higher the other intakes are.. i can tell you this, a flat hood would only fit if the air cleaner and carb stud were taken off (i was planning on putting a scoop on that hood, and redoing the z28 hood)

i did a "mock up" of my engine earlier, and this is what i came up with:

Pro 1 Top End Kit
CNC ported
jegs# 301-01210004

Eagle Chevrolet 400 Forged
4340 Steel Crankshaft
jegs# 356-440037505700

Eagle 327-400ci 5.700''
ESP Connecting Rods
jegs# 356-CRS5700B3D

SRP pistons?? .020 over

Comp Cams 12-900-9
Small Block 1955-98
jegs# 249-12-900-9

im still not sure what i want to do with the pistons.. i can get flat top to run pump gas or domed to have 13:1 comp.. it would be nice to get gas at the local station.. but race fuel definitely made the engine sound/perform much better

what are the advantages of running 6" rods compared to 5.7?

im already in the $4600 range for this block, just for the parts i listed.. are the dart cnc heads really worth it? how much more hp would i see with them compared to the pro 1 230cc?

also i dont really understand the idea with "quench" but i see a lot of talk about it

also with domed pistons, would i have to worry about piston to valve clearance at all?

the most important thing is, with the assembled heads, will that cam work with them, or will i need to change stuff?

I put a good amount of pump gas motors together stay with the flat tops. and I do think the cnc heads work better but I understand a budget and if I were a lil tight on it I would go with a set of dart 215s over the 230s thay work great and for the cam you picked out I think you will have a great street motor with 10 sec potential.

I put a good amount of pump gas motors together stay with the flat tops. and I do think the cnc heads work better but I understand a budget and if I were a lil tight on it I would go with a set of dart 215s over the 230s thay work great and for the cam you picked out I think you will have a great street motor with 10 sec potential.

why the 215 over the 230's?

is this just a preference, or a reason (intake runners too big?)

and you are saying a 10 second engine using pump gas??

this is with the parts that i listed above, correct?

As many here know, I've ONLY done 400 builds over the past 20 years. It is my preferred platform for many reasons. Always powerful, reliable and relatively lighter. You can make well over 600 reliable horsepower for years to come.

As for heads, if you can afford the AFR's or comparable, get them. But I will say this... I have a set of old iron Crane Fireball heads (remember those?) fully worked that flow almost identical to the Track 1's and AFR's. I had the Fireballs on a 10.5:1 400 combo last year and it produced over 500 hp and dipped into the 10's on a 3300 lb almost daily driver. So in my opinion, don't skimp on heads, but weight (aluminum vs iron) is the only real reason I switched heads this year, not flow characteristics.

Good luck.
Jim

i am planning on getting the block bored 20 over.. thats all it needs, and they make the pistons for it.. should i get it sonic checked for this amount? the guy who sold me the block told me it would need bored 20 over to remove the ring groove.. but could i just get it honed instead and use stock sized pistons?

On the 400 factory block I really do not like to go more than 30 over on a bore. 20 should be just fine. The original owner's clue about ring groove is somewhat on, but you'll also need to make sure the cylinder wall taper is machined out of it (which a hone does not address).


after looking at cams, i kinda like this one: http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=310&sb=2

I LOVE solid rollers! The grind on that cam looks like it would be a very fun street cam. The springs on the heads you are looking at ought to work very well for this cam. I don't see the open pressures listed with those springs but you'll want to be at about 200-240# on-seat and no more than 400-ish# open for the type of lift you are talking on that cam.



i dont really have a desired rpm range, im just looking for a beast of an engine.. even though i doubt it will see more than 6500rpm.. i would like to get the 4 bolt caps put on it.. how much would that cost for a machine shop to do? i dont like the idea of drilling a block, i would be afraid of messing it up

OH YEAH the splayed caps are not a "do it at home" project. The last block I did with them cost me about 400.00 bucks for the caps themselves and about 200.00 bucks to have the machine work done to accept them.


most of the cranks i am looking at are internally balanced.. so i can use a 350 balancer/flywheel.. does anything else have to be balanced?

They are usually balanced the same as a 350 so you balance the rotating assembly as a 350 then purchase a flywheel and balancer for a 350 application, piece of cake.


i already had a weiand xcellerator (hi rise) on my old engine, and it fit under the stock z28 hood.. im not sure how much higher the other intakes are.. i can tell you this, a flat hood would only fit if the air cleaner and carb stud were taken off (i was planning on putting a scoop on that hood, and redoing the z28 hood)


Great little street manifold, I have run it a few times in the past and would again!


im still not sure what i want to do with the pistons.. i can get flat top to run pump gas or domed to have 13:1 comp.. it would be nice to get gas at the local station.. but race fuel definitely made the engine sound/perform much better

13.0:1 Is a tough row to hoe for a driver. If your quench is perfect and you run aluminum heads with no "hot-spots" you can often get away with 12.0:1 on the street, but if you have no aversion to really pricey fuel 13.0:1 can be fun. However, that being said, the "bleed off" at low RPM on the cam you have selected is not really there for the dynamic compression to be correct for the 13.0:1 CR and that cam grind. You may want to use a grind with more overlap to handle that.


what are the advantages of running 6" rods compared to 5.7?

6" rods make much better use of the power stroke. There is less power deflection (that is the condition when the straight push of the piston is essentially losing efficiency because it is pressing on a rod that is at a great angle in the cylinder and some of the force is lost or shunted to the side instead of directly into the crank throw.). The risk however ends up being that longer rods weigh more usually unless they have been machined out of some exotic material (unobtainium) or by some exotic process so you do have to pay more to get a lighter piston to try an alleviate this condition. A heavy rod piston combo results in more reciprocating weight which is harder to balance and wears out much faster.

CNC heads are worth it in most cases, but when budget is a really big factor going with a non CNC head that has good "out of box" flow numbers is a good alternative. Dart typically can satisfy this with almost all of their offerings.


Quench is a long subject... but in a nutshell it partly describes the flame path and the ignition characteristics of the gas/air charge in the cylinder. Most people mistakenly have the idea that the charge ignites all at once and simply "explodes". In reality there is an ignition point in the charge and the path that flame travels from that point to consume the entire charge is the "flame path". The "quench" kind of describes the way the head and piston interact to control when the ignition is achieved and what direction(s) the flame path takes. The way these two components "control" the flame path is with the distance from the piston to the opposing head combustion chamber surface, the distance from the piston to any "hot spot" on the head and the way these measurements change during compression (IE does one spot get close first then rapidly close the distance around the rest of the chamber thus producing a "guided" flame path etc, as I mentioned a very lengthy subject that I am mutilating here but just trying to get your juices flowing). When dealing with really high compression engines you can create a "quench" interaction that guides the flame path in a desirable way and can minimize low RPM pinging.



also with domed pistons, would i have to worry about piston to valve clearance at all?
Definitely will have to make sure the dome will work with the combustion chamber. Also will have to make sure that where you plan to degree the cam works as well. You will make new friends with definition putty :-) Flat tops are great for the street but given the CR you are targeting you will probably have to use a dome for both lightness and to control piston protrusion.


the most important thing is, with the assembled heads, will that cam work with them, or will i need to change stuff?
The only worry I have is that the spring may be a bit stiff on the "off the seat" side (this means the valve will close very severely and you'll be giving up power to push that spring that could be used elsewhere). Your best bet is to call Dart and give them the lift characteristics and find out what the fully open spring tension would be (they might ask what push rod length, what rocker ratio and what deck height is being dealt with, in your case these are most likely to be all stock if I hear things correctly). There is usually just a part number variation that will order the same part with the correct spring tensions.


Wow, I better actually do some work today! LOL Anyways, as I mentioned, these are just my opinions, there is a ton of other really useful information I have seen in this thread from other people with real experience! Read and study twice or more and buy once! LOL
-Adam

6" rods make much better use of the power stroke. There is less power deflection (that is the condition when the straight push of the piston is essentially losing efficiency because it is pressing on a rod that is at a great angle in the cylinder and some of the force is lost or shunted to the side instead of directly into the crank throw.).

Newton's laws don't seem to bear this idea out, as each unit of force on the cylinder wall has to have an opposite force on the crank, i.e. torque. Jere Stahl, in his long study of the effects of rod length, says:

...Short rod exerts more force to the crank pin at any crank angle that counts ie.--20° ATDC to 70° ATDC. Also side loads cyl walls more than long rod. Will probably be more critical of piston design and cyl wall rigidity...
Piston is higher in the bore when Rod-Crank angle is at 90° even though at any given crank angle the piston is further down. Thus, at any given "time" on the power stroke between a rod to crank pin angle of 10° and ie. 90°, the short rod will generate a greater force on the crank pin which will be in the 70° to 75° ATDC range for most engines we are concerned with...
Note, that even though power is a funtion of air flow and air flow should be roughly constant for the same instantaneous piston speed (neglecting the afore mentioned factors), the power may not be the same because of the lever arm effect between the crank radius and the connecting rod. (As we noted earlier, the shorter rod should have the advantage in the lever arm effect.)

http://www.stahlheaders.com/Lit_Rod%20Length.htm

All that said, a 6" rod with a 3.75" stroke is actually a pretty short rod, something in the 6.75" range would give the same ratio as a 5.85" rod in a 327. I had a Studebaker V-8 with a r/s ratio of 2.04 and those certainly aren't remembered as great powerhouses.

That is a great article onovakind67, thank you!

http://www.stahlheaders.com/Lit_Rod%20Length.htm

Considerations in there that I have not had the chance (or perhaps intelligence!) to ponder :-)

-Adam

A bit more information on the Rod length/Ratio eternal debate (lifted from Horst Hardenberg's "The Middle Ages of the Internal combustion Engine")...

Rod/stroke ratio, an important factor in engine design, is the ratio of the length of the connecting rod to the length of the crankshaft's (or piston's) stroke. An increase in the rod/stroke ratio (a longer rod, a shorter stroke or both) results in a lower piston speed. A longer rod (and consequently, higher rod/stroke ratio,) can potentially create more power, due to the fact that with a longer connecting rod, more force from the piston is delivered tangentially to the crankshaft's rotation, delivering more torque. A shorter rod/stroke ratio creates higher piston speeds, but this can be beneficial depending on other engine characteristics. Increased piston speeds can create tumble or swirl within the cylinder and reduce detonation. Increased piston speeds can also draw fuel-air mixture into the cylinder more quickly through a larger intake runner, promoting good cylinder filling.

This link at wikipedia has a nice section called "output limitations" that contains information specifically about the 400 that may be indirectly related to why I ended up with a 6" rod preference for 400s as most of my , cough cough, "knowledge" was originally lifted off of machinists at machine shops that were willing to talk!!!

http://en.wikipedia.org/wiki/Four-stroke

wow awesome!

i saw two different types of splayed caps.. one from eagle.. they were $90, and one from milodon for $200

is there any HUGE difference between them, or will they both work the same?

i just acquired an extra $200 and i would like to start getting the block machined

Well, Milodon is usually going to be a very high quality part when compared to almost anything, and they have been the only ones I have used. It seems the price has come down quite a bit on them, or you found a great deal! I have used Eagle rods and cranks with fairly good success so I don't have any aversion to the Eagles.

You will need them in hand before machining can take place and if I remember correct, the block can NOT have been line bored prior to this. Make sure you verify price and if your block can be done first with your machinist (also ask them about the Eagle vs. Milodon question, they may actually have experience with the two)!

The reason I would use the 215s over the 230s one for the cam you picked you are not going to spin it up to 7000 rpm and reason # two all the 230s I have seen were a tad bit lazy if you dump some money into them thay will work and the 215s flow great # out of the box and performe well. And yes if you have a car that is 3400 lbs or less I think with the 215s and on pump gas you can run 10s on motor. I forgot to mention with the cam you picked I would run a 1.6 rocker ratio to give it some more lift. Gear Head them crane fire ball heads are great heads its gitting hard to find them with out cracks in them these days but thay made great power and were the choice for a lot ok low buck street racers.

Milodon splayed caps are still nodular caps, Eagles are billet steel. Pro-Gram are the better quality caps, but expensive. I paid more money for my forward Pro-Gram cap than I did for the middle three Eagles.

Stay away from domed pistons. No reason to run these today. The larger the bore and the longer the stroke the higher the compression will be with everything staying the same. Run a good set of forged flat tops, very easy to build 12 or 13:1 into a flat top 406 with the vast choice of heads out there and zero decking the block and selecting the correct gasket to get your quench in around .040 with steel rods. You'll need more quench if you run aluminum alloy rods. You have cylinder head chamber choices all the way down to 48 or 49cc today. Lots of choices at 55 -62. You can flat mill about 5 cc out of any production head before you run into trouble. That's figuring .006" flat mill per 1 cc. So you can safely cut a set of 64 to 59, a set of 62 to 57 or a set of 55 to 50. There simply is no reason to run domed pistons. If you do it's inviting detonation at the CR you're trying to use.

A bit more information on the Rod length/Ratio eternal debate (lifted from Horst Hardenberg's "The Middle Ages of the Internal combustion Engine")...

Rod/stroke ratio, an important factor in engine design, is the ratio of the length of the connecting rod to the length of the crankshaft's (or piston's) stroke. An increase in the rod/stroke ratio (a longer rod, a shorter stroke or both) results in a lower piston speed. A longer rod (and consequently, higher rod/stroke ratio,) can potentially create more power, due to the fact that with a longer connecting rod, more force from the piston is delivered tangentially to the crankshaft's rotation, delivering more torque. A shorter rod/stroke ratio creates higher piston speeds, but this can be beneficial depending on other engine characteristics. Increased piston speeds can create tumble or swirl within the cylinder and reduce detonation. Increased piston speeds can also draw fuel-air mixture into the cylinder more quickly through a larger intake runner, promoting good cylinder filling.



Piston speed is stroke*rpm*2. Rod length does not alter it, only stroke length or rpm does. A 4" stroke at 1000 rpm will always travel 666fpm irregardless of rod length.

You may be trying to refer to the length of time the piston takes to reverse directions? Or how quickly or slowly it reverses?

Piston speed is stroke*rpm*2. Rod length does not alter it, only stroke length or rpm does. A 4" stroke at 1000 rpm will always travel 666fpm irregardless of rod length.

You may be trying to refer to the length of time the piston takes to reverse directions? Or how quickly or slowly it reverses?

You are referring to average piston speed, instantaneous piston speed is another animal.

You may be trying to refer to the length of time the piston takes to reverse directions? Or how quickly or slowly it reverses?


I like the term instantaneous piston speed. Just don't want it confused with piston speed.

You could call it acceleration and deceleration. Just don't call it piston speed. Because it's not moving for a few degrees. Edit: and it's those few degrees and the dwell time and resultant crank angle that is what's sought after.

The 4" stroked piston will still only travel 666 feet in one minute at 1000 rpm.

you guys are confusing me now!

can you guys (especially the ones who build 400's a lot) give me a quick list of parts you would use if you were in my situation?

i literally have just a bare block sitting here, no bolts no screws, nothing.. the only thing it has is a dowl pin for the transmission.. and only one at that

i just need to know what i should do and buy

just let me say this, the less machine work the better, personally i dont want to get the block decked

right now i need to get it bored,honed, and maybe aligne bore/honed if i go the 4 bolt way this is probably in the $1000 range for that including the price of main caps

You will be fine with the parts you have listed The con. rod I would run 5.7,5.85,or 6.0 length but remember chevy put all of thers out with a 5.565 rod and thay all lived just fine.And as for sppending a $1000.00 on the block you do know you can sell that block for $200-$300 and buy the new dart sportsman block its a step under the LIL M block all you will have to do is finish hone the cylinders to your pistons it comes with splayed 4 bolt mains it cost around $1600 shiped to your door from jegs or cnc offers them blueprinted and shipped for $1800.00 just an option for you.

You will be fine with the parts you have listed The con. rod I would run 5.7,5.85,or 6.0 length but remember chevy put all of thers out with a 5.565 rod and thay all lived just fine.And as for sppending a $1000.00 on the block you do know you can sell that block for $200-$300 and buy the new dart sportsman block its a step under the LIL M block all you will have to do is finish hone the cylinders to your pistons it comes with splayed 4 bolt mains it cost around $1600 shiped to your door from jegs or cnc offers them blueprinted and shipped for $1800.00 just an option for you.

thanks, i would rather not sell the block, i just bought it last week

i think i am going to get it sonic checked soon and then start saving up some money for machine work

And on a side note alot of after market internal bal. cranks have large counter weights that dem it nessary to use longer rods. Sounds like you will have a great running small block.