I have a chance to purchase a 64 Corvette from an old friend. He has been sick since the early 70's when he put this car in his parents garage and never drove it again. He has decided to sell it, today he is in a wheel chair. I do not mind refurbishing the brakes, fuel system etc but I wonder how this engine will run with todays fuels? Does anyone run this engine today in stock form. I know it still has the solid lifters and 11.25 to 1 pistons. My friend is the second owner, I also know the guy that bought this car new. The car unfortunately is a mild custom. It has front and rear fender flairs, full rear spoiler, lower front pan corners shaved of the parking lights. The car looks great painted in a Mopar plum crazy type color. As a convertible it really looks tough with the roof down. The engine does concern me, I do not want to get into internal changes. What do you guys think?
Bill

i dont know if they make lead additives any more!! at least not down here!! somebody will know though...sounds like a nice ride with a stout motor!!

Lead isn't the issue getting it to run on 91 or if you can get it 93 octane is the problem.With a slow timing curve and eletronic ignition you may be able to run it ok.But I don't think it will be great.If the price is right get it if it wont run on the crap they call gas swap in a lower comp. 350 and enjoy it.

Bill

The 11:1 factory rating was with steel shim gaskets. If it's been torn down and has standard rebuilder head gaskets in it the compression will be more like 10.25-10.5:1 depending on head chamber size and overbore.

I'd mix in a little 110 octane race gas for piece of mind and go. :thumbsup:

Mark

This is my opinion with an Original Rare Engine.

It is my experience an original engine that is 45 years old, regardless of mileage, should be torn down for inspection and thoroughly cleaned. If the bore is within specs, honed and new rings installed. Valves and Seats touched up and NEW springs, oil pump bearings, seals and gaskets. Don’t expect the Old Dried Out Seals and Gaskets to work.

You will no doubt find out what you have.

At this time you can do what ever is necessary to lower the static compression or choose a cam to bleed it off without sacrificing bottom end.

Simply installing a thicker Head Gasket may not work as you will increase the quench and promote knock.

If the Bore, Pistons and Pins pass inspection, I believe you could replace the 58 CC Fuelie Heads with perhaps 64CC 68 Turbo Flows or go after market to lower the Static to around 10.25 and choose a cam to achieve a DCR of around 8:1 to run 91 Octane Safely.

This new gas is nothing like our old gas and most times you can not detect or hear ping that is detonating our old engines, until it is too late.

Bill, sounds great- please post a photo. I can't remember the last time I saw a custom Vette at a cruise!

I think it will. That engine is the same spec as a 302 with a longer stroke. The duration of the 30-30 cam is soooo long that the "dynamic" compression is on the low end of the scale. The stock 302s with good tuning run fine on 92 octane. I use California 91. Hopefully JohnZ will comment.

i dont know if they make lead additives any more!! at least not down here!! somebody will know though...sounds like a nice ride with a stout motor!!

Octane Supreme 130. I must admit I use a little to take the 91 to 92 octane but I have run the engine on straight 91 octane. I don't drive a lot of miles.
http://www.batterystuff.com/fuel-treatments/OS6q.html

If it's original it will have 461 or 462 large valve 64cc heads. The old TRW pistons will have a .125 dome which is only about 5.3cc.

If someone took the heads off back in the day it may already have .039-.041 head gaskets in it which would give you around 10.25-10.5:1.

And as Gary stated, the old 30-30 cam will lower your dynamic compression.

Check everything out. Mix some 110 octane in with your premium and fire that puppy up. Guaranteed to put a smile on your face. :thumbsup:

Mark

Make sure that you have steel shim head gaskets (stock or 0.015" felpro # 1094) on that motor. The QUENCH is essential to proper combustion and detonation suppression on a wedge head engine.
Unlike like the incorrect previous post about using the 0.040" thick blue felpros and dropping the compression to 10.25:1, it won't and it will cause detonation with a normal 0.025" deck height. The thick gaskets at most will drop the comp 0.1-0.2 points.

That big lazy 30/30 cam will be fine with 11.25:1 compression and 93 octane gas.

Make sure that you have steel shim head gaskets (stock or 0.015" felpro # 1094) on that motor. The QUENCH is essential to proper combustion and detonation suppression on a wedge head engine.
Unlike like the incorrect previous post about using the 0.040" thick blue felpros and dropping the compression to 10.25:1, it won't and it will cause detonation with a normal 0.025" deck height. The thick gaskets at most will drop the comp 0.1-0.2 points.

That big lazy 30/30 cam will be fine with 11.25:1 compression and 93 octane gas.

Good lord, using the rebuilder gaskets wasn't a recommendation. And yes, it does make a significant difference in static compression when compared to a steel shim gasket. Recheck your math.

Using 64cc chamber, stock bore and 5.3cc dome:

.015 gasket-10.97:1
.039 gasket-10.25:1

That's just a shade more than the 0.1-0.2 drop stated in the incorrect previous post.

Mark

... And yes, it does make a significant difference in static compression when compared to a steel shim gasket. Recheck your math. ...

Mark

^^^ X2 :thumbsup:

I was just adding 'the math' for him when you added it to your post Mark :beers:
Tom, Head Gasket thickness very definately effects CR - Engine Math 101 ;)
Same as changing chamber size, deck height or dome volume :yes:

I own one.. I built the motor to spec with true 11.25 to 1 compression using shim head gaskets and cutting the heads to achieve the true ratio... not just guessign with the OE pistions.

I have the 30-30 cam in it, and it runs all day on pump premium (generally 92 or 93) i have points, and a very fast ignition curve... initial is at 14 and 24 additional comes in by 2200 rpm... full manifold vaccuum.

i have AC46 plugs in it... which is very hot, and generally would really cause it to be a marble machine... but the carb is jetted appropriately for a stout cam like the 30-30 it runs like a dream and has no knocking what so ever.

the hard seats is BS... unless you are pulling a trailer, you can run them with the OE seats, and a tank of the Leaded stuff once every two years, and you'll be fine. Honestly, the risidual lead thats probably already in the chamber from years past will probably suffice. :D

DO NOT DROP THE COMPRESSION, and DO NOT REPLACE THE 30-30 CAM (that is if it hasn't been done already)
you can put a dial indicator on the pushrods and determine the lobe lift to see if you have the .485 lift Duntov 30-30...

true that the L76 is basically a stroked version of the DZ302....
or the DZ302 is a destroked version of the L76 ... the Z motor has a better intake, and a larger holley... thats it.

but the additional 25 cubes, and the 2.5 ramshorn manifolds make a world of difference in the way it will run in tuned stock form vs a tuned stock DZ302.

i have both, both are blueprinted, and run to their maximum potential... both run on 92-93 in 90degree weather without issue.
i say go for it.. i love mine.

do a search for Aaronz28 on the corvetteforum.com you can find videos and a photo documentary of my complete paint and mechanical restoration on the car.

A

This car has not been run since the early 70's. Just before the car was "parked" the lower end had new bearings installed, the heads were not removed, I have to assume the shim gaskets are still in place. A friend of mine did the bearing swap. I know this engine still has the original heads with 62cc if I remember correctly. The original Holley and correct intake are still in place as are the 2 1/2" cast iron exhaust manifolds. If I purchase this car it would probably be worth while installing flat top 4 valve relief pistons like the 300 horse version of the 327. This will lower the compression to a more reasonable 10 to 1 compression. Horsepower will be slightly less, but the engine should run great with the 30-30 cam. My friend is taking bids for the car, I'll let you all know what the final outcome is.
Bill

Aaron,
I read your threads in the Corvette forum, very interesting. My question to you is, dropping the compression to 10 to 1 will have what affect when using the 30-30 cam? The obvious is a lower dynamic compression because of the cam overlap, and secondly a drop in engine horsepower. What else am I missing here if anything?
Bill

Fwiw, my stock chambered big valve -461 heads cc at 66.0 and 66.+ cc's b/c of the factory intake valve chamber de-shoud plunge-cut.

And right, the old 30-30 cam should run fine on 93 or so octane, imho. And they used .020" thick GM/Mr. Gasket type steel shim headgaskets as did just about everything did back then.

pdq67

i own 2 cars with 11-1 compression and I run them on a 50/50 mix of pump premium and cam 2. i have been doing this for years now and it works out great.

Thanks for the backup 69z28boy.;)

It is kind of funny that ol' Zora designed a cam the way he did.

Make sure that you have steel shim head gaskets (stock or 0.015" felpro # 1094) on that motor. The QUENCH is essential to proper combustion and detonation suppression on a wedge head engine............

Not really so for this combo. I have the GM .028" gaskets and they work fine. Again probably because of the low dynamic compression.

Engine Math 101 [/I];)
Same as changing chamber size, deck height or dome volume :yes:

...and bore too.;)

...and bore too.;)

I heard that rumor too :stirpot:

Bill

I would keep the engine as is. Best engine Chevy ever made. ;)

If you win the bidding, be sure to help your buddy out of that chair and into the passenger seat for a ride. Nailing second gear at 6500 rpms will put a big smile on both your faces. :thumbsup:

Mark

Aaron,
I read your threads in the Corvette forum, very interesting. My question to you is, dropping the compression to 10 to 1 will have what affect when using the 30-30 cam? The obvious is a lower dynamic compression because of the cam overlap, and secondly a drop in engine horsepower. What else am I missing here if anything?
Bill

it will be horrible in a word...

the 30-30 already reduces compression because of the huge seat to seat duration...

you do not want to put this in a 10 to 1 motor... unless you stroke it to 383.

A

Bill,
if you decide to put flatops in, and a smaller cam... you are likely to run into more detonation problems than if you rebuild it to stock blueprint specs..

the 30-30 cam has ridicluously long flanks on it... probably about as gentle as you can get for a +.450 lift cam.

what happens is that the valves move off the seat and kinda sit there and lolly gag about as slow as you can imagine to get to its .325 lobe lift (or whatever it actually is)

all that time wasted does two things... bleeds off compression and makes the engine sound very lopey... it does other things too like keeps your valves and seats around for a very long time, is easy on valve train parts etc...

the 11.25 to 1 factory compression ratio really is required to run tht cam effectively becasue the cam needs the compression to make any low end torque.

now, i know there are guys out there that have run them in 10 to 1 motors, and swear that they run great... but they'll get passed by Grandma's Aerostar until that motor hits about 3500 rpm....

the higher compression really helps the low end and makes the engine much more snappier and effecient.

now... for comparison sake,

a 10 to 1 motor with a tiny cam like the comp 268 or even something a tad bigger, will likely have much more trouble with detonation because they, in effect, let the engine built more compression becasue they keep the valves closed longer and let the piston start the compression stroke earlier.

if you rebuild it, i highly recommend blueprinting and making sure that you have a true 11 to 1, and advance the cam 4-6 degrees in the motor.... it will run forever on pump premium, and you'll haev a blast doing it... plus it will be all stock.

not that you can't make more power using other stuff, and more modern parts to boot, but you already have the best that Chevrolet ever put into a Small Block in the muscle car era... and it runs well...

fly to Michigan, and I'll take you for a ride in my L76. :D

A

Thanks for the backup 69z28boy.;)

It is kind of funny that ol' Zora designed a cam the way he did.

I couldn't agreee more.
Its funny though... if you talk to guys like Jere Stahl, and Wayne Guinn, they even say that it was one of the worst GM cams ever. LOL...

to me, that cam is the best of everything in a OE hi-po setup...

i've got the 140 in my Z now, but that car has headers and all the go fast goodies. the Vette is pure stock and I love it.

A

I couldn't agreee more.
Its funny though... if you talk to guys like Jere Stahl, and Wayne Guinn, they even say that it was one of the worst GM cams ever. LOL...

to me, that cam is the best of everything in a OE hi-po setup...

i've got the 140 in my Z now, but that car has headers and all the go fast goodies. the Vette is pure stock and I love it.

A:thumbsup::thumbsup:

I would like for them to say exactly why it is a bad design.:confused:

And I don't want to hear things like "modern cam designs are better........"

Aaron,
I have a few questions. The 4 degree advance on the cam will have what effect on the engine performance? Will doing this create a situation where my valve to piston clearance may become dangerously close? What about my idle quality, will this change smooth out the idle or make it even lopeyer? I am a novice at understanding all of the little specifics pertaining to cam selection and their effects on engine performanc. Based on everything I am reading, I should essentially keep the engine bone stock and simply use premium fuel. The performance should be good without doing anything else. Thanks in advance, Bill

Advancing the cam will put a tad more bottom end into the motor...
it just builds a bit more cylinder pressure.

generally, advancing the cam does close the piston to valve clearance, but you have plenty of room using the OE pistons with that cam...

i know guys who have advanced them 8 degrees with no issues.

as far as the idle. you probably won't notice any difference... since advancing the cam does build a bit more pressure, the off idle response will be a tad snappier when compared to an identical engine with the cam in strait up.

honestly, you can't even buy a cam these days without the 4degrees advance ground in. I advanced mine another 2 degrees for good measure, and the engine loves it.

i drove the car today in 95 degree weather here in michigan... with 11.25 to 1 compression, 93 in the tank, 3.70 gears, and i was able to take off in 3rd gear without any knock..

that is with 38 total timing....


so you will have absolutely no issues with that cam and 11.25 to 1 using pump premium...

the only time i can even get it to knock is if i put it in 4th at about 15 mph and floor it....

but i don't know of anycar without knock sensors that will pass that test on a 95degree day. :P



when you rebuild... if you rebuild....

make sure to have the heads cc-ed, i've seen the "64" cc versions which should be on your car anywhere from 59 cc to 68 cc on virgin castings...

if your heads have never been off, then you should be in the 62-64 range.

once you know the head chamber size, you can have them milled accordingly to get that 11.25 to 1... you'll want the OE pop-up slugs.... and use the Felpro embossed shim head gasket.... i think it is .015 or .019.... that will keep your quench right, and get you right at that 11.25 to 1 compression.

the only upgrade you MUST do is the rods... those Factory small journal rods are iffy at best.

spend some time on the Corvetteforum and read about it.. I think Crower makes the ideal, rod for the motor, and they won't break...

the steel crank, crower rods, and forged OE slugs will let that 327 spin to 6500 all day every day.... (JUST LIKE MINE DOES) LOL

any whatever you do, don't let anyone talk you into running the LT1 camshaft.... it is a popular change among the vette guys...

i won't get into the performance debate... but if you build your long block to be at 11.25 to 1, the LT1 cam will not run well on pump gas... it has less intake duration and just enough less that it will cause the motor to Detonate...

i had one in my Car when I got it.... and it would ping like crazy....
haveing had much experience with the 30-30 cam in other cars, i knew something wasn't right..

when i pulled the motor apart, it had the thick felpro head gasket and the LT1 cam...

i had the heads milled, put the shim gasket in, and the 30-30 cam..recurved the dist for a much faster ign curve, and voila...

the car runs 100% better and no more knocking...

i raised the compression at least a point with the changes i made, yet the 30-30 cam tolerates the Pump premium, tighter quench, and faster ignition curve much better than the lower compression engine with the LT1 cam...


enjoy

A

:thumbsup::thumbsup:

I would like for them to say exactly why it is a bad design.:confused:

And I don't want to hear things like "modern cam designs are better........"

exactly... and thats all I get out of them...

crap like... that old Duntov cam is a dinosaur and there are much better grinds out there today..

well, you've probably read my cam journeys...and I've yet to find a better set of cams than the 30-30 and the 140 in applications using the GM heads and intake.

not saying that it cant be done with good heads, intakes, etc.... but for my money using the GM castings, i'll stay with those two designs... :D

plus its nice to say... "yep... all stock"

A

And if you really do want to go to the trouble of de-tuning her back to 10.25 to 1 CR, the GREAT old Little Duntov cam, the -097 is an dandy!

It was used in the the big 283 and 340/360 hp/327's w/ the medium valve heads.

I DD it in my old about 10.25 to 1 CR's junk301 and it was a real HOOT!

Now back to what's wrong w/ the old 30-30, NOTHING when installed in the engines it was designed to be ran in and they are all 11.+ CR'd!

The 290hp/302, the 365/375hp/327's and the original 360/370hp/350 MULE engine that GM chose to run the smaller -178 solid lifter cam in for better so-called driveability.

It's just that there are more modern cams now is all is why other's are down on it.

One old cam that is better is the old Isky Z-30 which is 290/250, 108/108, .485" gross lift whereas the 30-30 is 346 per GM/314, per WBR, and 304 per the late Pat Kelly/254, 114/112, .485" gross lift and both these cams lash at .030" hot!

And the guy's bad-mouth the old 350hp/327 hy-cam, the -151 for the same reasons!

pdq67

Guys I learned an awful lot of valuable information with this post and I must thank everyone that responded. Now all I need to do is wait to see if my offer is accepted or rejected. I wish I could post pictures of the car, but the car is literally buried under almost 40 years of junk accumulation in a very small single car garage. The "stuff" surrounds the car and is in fact on the car as well. The clutter is so bad that with the garage door open a person would never see the classic buried in this mess. I will keep everyone posted on the final outcome.
Bill

And back again, my old junk301 ran who know's what thick beam 283 rods b/c the '55 265 rods that was w/ the crank were way too thin to run. They are like the modern, thin, 262/267/305 rods that GM run's in the low-po smog engines. The 305HO has thicker rods like the 350 if not mistaken.

And don't worry about the SJ rods little bolts b/c the '67 Z-28 had them in it and it would go above 8,000 rpm easy! And I shifted my old junk301 above 7,000 rpm all the time. And w/ new points, at 7,500 for a week! Then the nylon dizzy point cam follower would wear down and it'd only go to like 7,000.

pdq67

Well I did not win the bid on the Corvette. I thought my bid was fair at $20K, the winner took it away for $32.5K. I know the powertrain was original, but the mechanicals of the car needed to be gone through completely. Some people around here have very deep pockets. The car was real cool back in the day and would be equally cool today, I feel it was just too much money to spend for that car. Another car will come along one day, I just need to be patient.
Bill

$32.5K sounds high to me also.

........ 304 per the late Pat Kelly/254, 114/112, .485" gross lift and both these cams lash at .030" hot!........pdq67

Late Pat Kelley? He is deceased?

........ 304 per the late Pat Kelly/254, 114/112, .485" gross lift and both these cams lash at .030" hot!........pdq67

Late Pat Kelley? He is deceased?

Well I did not win the bid on the Corvette. I thought my bid was fair at $20K, the winner took it away for $32.5K. I know the powertrain was original, but the mechanicals of the car needed to be gone through completely. Some people around here have very deep pockets. The car was real cool back in the day and would be equally cool today, I feel it was just too much money to spend for that car. Another car will come along one day, I just need to be patient.
Bill

WOW, i'm trying to get 45k for mine fully restored...

32 is definately too much for a 64 Corvette that needs all its mechanicals checked.

Oh well..
It would have been a fun car for sure.

A

Aaron,
If I had the money for your car it would be in my driveway already! You did a beautiful job on that restore, and I believe your price is fair. We all need to remember the uncertainty that our economy is in at this time. Hopefully things will turn around in short order.
Bill

Yes, Pat's gone now, I want to say posted over on Team Chevelle a while back.

pdq67

The cam overlap does not cause the lower d.c.r., it is the late intake closing point of the 30/30 cam with the new lower 10:1 c.r. that will cause the lower d.c.r. and resulting loss of power due to less cylinder pressure. Cam overlap happens when both the intake and exhaust valves are open at the same time so has no affect on cylinder pressure. The overlap will have more of an affect on the idle, vacuum, and low speed driveability when the c.r. is dropped to 10:1 with no change in cam timing but does not affect the d.c.r. One could advance the cam to help build more cylinder pressure(closes the intake sooner) and possibly regain some lost h.p.

Well, I didn't get here until the horse had left the barn (for way too much money - the guy must have really liked customs), but I'll throw my two cents in anyway. I've had several 327/365's (one was a tanker, shoulda kept it) and '69 Z/28's (my current one is on the new Hagerty magazine cover below), and all of them will run just fine all day long with 11:1 on pump premium with the right jetting, correct advance map, and manifold vacuum advance with the right can, thanks to the 30-30's late-closing intake valves. Leave them alone - dropping the compression turns them into a turd.

:beers:

Yes, Pat's gone now, I want to say posted over on Team Chevelle a while back.

pdq67

Found it here:http://www.chevelles.com/forums/showthread.php?t=265311

I talked to him on the phone once about his DCR calculator. How old was he?