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1964 Corvette 327/365 horse, will it run with todays fuels?

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sbcBill

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Discussion starter · #1 ·
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
 
#2 ·
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!!
 
#3 ·
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.
 
#4 ·
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
 
#5 ·
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.
 
#7 · (Edited)
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.

SPARKY69 said:
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!!
Click to expand...
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
 
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#8 ·
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
 
#9 ·
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.
 
#10 ·
hhott71 said:
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.
Click to expand...
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
 
#11 ·
mbrekke said:
... And yes, it does make a significant difference in static compression when compared to a steel shim gasket. Recheck your math. ...

Mark
Click to expand...
^^^ 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:
 
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#12 ·
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
 
Discussion starter · #13 ·
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
 
Discussion starter · #14 ·
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
 
#15 ·
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
 
#17 ·
Thanks for the backup 69z28boy.;)

It is kind of funny that ol' Zora designed a cam the way he did.
 
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#18 ·
hhott71 said:
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............
Click to expand...
Not really so for this combo. I have the GM .028" gaskets and they work fine. Again probably because of the low dynamic compression.
 
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#19 ·
Vintage 68;1239214.......Tom said:
Engine Math 101 [/I];)
Same as changing chamber size, deck height or dome volume :yes:
Click to expand...
...and bore too.;)
 
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