New to Corvette ownership

[Bill B.]

Re: New to Corvette ownership

I found this link to be very informative as well as accurate:

http://www.faqs.org/faqs/autos/gasoline-faq/part3/section-1.html

Welcome to the family and Good luck,
Bill Berger


1961 Black/Silver/Red Int. 283/315 FI
power windows. Frame off 65% completed.
1989 White/hard top/Grey Int. daily driver 167,000 miles

"The problem with Liberalism is that eventually you run out of other people's money" Margaret Thatcher

[Jerry W.]

Re: New to Corvette ownership

Just finishing a 62 340 hp rebuild...motor was tired...bored pistons .030 over...turned crank .010 under...used flat top dished pistons...heads were previously milled....combustion chamber 62cc....using similar new cam....using new brass valve seats...using conventional head gasket...hope all this works.

061 below is .042 gskt plus .019 piston below deck

Cylinder Diameter
(inches ex: 4.25)
Cylinder Diameter (mm)Stroke Length (inches ex: 4.25)
Stroke Length (mm)Number of cylinders (4, 5, 6, 8)
Number of cylindersChamber in cc's (ex: 119)
Chamber in cc'sPiston dome in cc's
(Dome = positive #, Flat = 0, dished = negative number)
ex: 22
Piston dome in cc'sGasket Thickness in inches (add plus or minus amount piston is in the hole) ex: .42
Gasket Thickness in mm (add plus or minus amount piston is in the hole)

The displacement is cubic inches or liters.
You also have a Compression ratio of :1

[Peter M.]

Re: New to Corvette ownership

Hello all, Wanted to introduce myself and tell you my story, then ask some advice.
My name is Dave Hurd and I live in Maine...

Rework the heads with the proper valve seats so you can run the car on today's 93 octane gas.

ALSO, did you ever live at Warren Lodge in Cockeysville, Maryland?

[Duke W.]

Re: New to Corvette ownership

Just finishing a 62 340 hp rebuild...motor was tired...bored pistons .030 over...turned crank .010 under...used flat top dished pistons...heads were previously milled....combustion chamber 62cc....using similar new cam....using new brass valve seats...using conventional head gasket...hope all this works.

Wow, brass valve seats, huh? Those oughta last at least 50 miles! "Similar cam": Oh, yeah, there are hundreds of those things to choose from and most are guaranateed to actually fit. Dished pistons, too. You can probably run it on kerosene.

It sounds like you got taken for a typical ride by some "engine builder".

Duke

[Duke W.]

Re: New to Corvette ownership

Rework the heads with the proper valve seats so you can run the car on today's 93 octane gas.

ALSO, did you ever live at Warren Lodge in Cockeysville, Maryland?

Valve seats have absolutely nothing to do with detonation.

Duke

[David H.]

Re: New to Corvette ownership

I have to thank you all for all of your input to this concern of mine. You have all been most kind to reply to this "rookie" corvetter. It appears that Corvettes are a breed all by themselves. (but I already knew that!)

My biggest concern with the car is that I bring it back to life in a fashion that my brother would be proud of and to me that is spelled "original".
You have all convinced me that I should rebuild the original motor as it came in the car even if I have to spend the money on higher octane fuel. However, it does not appear to me that that will be necessary if I can find 92 octane or higher at the pump, and I am determined that I can do that with some help.

thanks again to all!

[Mike G.]

Re: New to Corvette ownership

it will run fine on 93 pump gas with a lead additive. you can buy it from jack podell. my 57 fi car runs fime on it.

[Michael W.]

Re: New to Corvette ownership

It should run just fine on straight 91-93 octane if built correctly. No need for lead, avgas, race fuel, seafoam, STP, zMax or any other magic elixir.

[David H.]

Re: New to Corvette ownership

Just thought I would update this post.
I decided to pull the motor myself, with some help from my nephew Nate (the real mechanic) and a rented hoist. We did that last night in about an hour. Then pulled the pan off to get a look inside. Happy to say I found no rust what so ever! Today I mounted it to the new engine stand and started to pull it apart. I hadn't done this in about 30 years so I took my time. I put all the bolts in plastic bags and labeled them as I did. Took lots of pictures too. Pulled the manifold off first. Again no signs of rust anywhere. Then we pulled the heads and verified that they are original X 461 heads. Looked for a blown head gasket but didnt really find it. One of the cooling channels was totally plugged with crap tho. Did notice that on all cylinders, right around the spark plugs was wet. This motor definately has been out before. New freeze plugs, and no ring ridge at all. Piston caps have markings for which cylinder they go to also. I may not have to do a complete rebuild after all. All in all it looks to be in pretty good shape for the shape she's in. Can anyone tell me anything about the pictured pistons?

[Jim T.]

Re: New to Corvette ownership

Since you mentioned a cooling channel plugged with crap recommend removing the 2 block drain plugs and checking out the cavity. Removal of these plugs when flushing the coolant system assists getting the coolant out.

[Mark Z.]

Re: New to Corvette ownership

Not an expert but from those pictures your intake valve (probably) is 'kissing' the piston and you have water from extreme condensation or mechanical failure (cracked cast iron or blown head gasket, intake gasket leaking into lifter galley). Hopefully the oil soup is from an easy fix.

[Paul J.]

Re: New to Corvette ownership

David, looks like that piston's tagged a valve. There may be some other damage that you can't readily see.

Paul

[Michael W.]

Re: New to Corvette ownership

I'd be interested to know how thick the layer of carbon is on top of those pistons.

[David H.]

Re: New to Corvette ownership

The carbon does not appear to be heavy. I am trying to determine if the engine has had a recent rebuild from talking to my sister in law about it. It looks as if it has been done not too long ago but I was not aware of it being done.
The top of all eight pistons look very similar to the one pictured here. I thought they were made this way but on closer inspection there is some difference in some of them. If this is the piston tagging the valve, it is tagging it pretty hard as the ridge you see at 3 oclock is rather prominant. The larger ridge on the top is on all pistons and the shorter ridge below it only shows on this one piston. I inspected the head gaskets and there were no obvious breaks in them. THe block will be checked for cracks as will the heads. I dont think it will be an easy fix but it will get fixed.

[Duke W.]

Re: New to Corvette ownership

Before you do any more disassemby and possibly destroy evidence, suggest you spend some time researching the archives on forensic teardowns.

Things like measuring head gasket thickness and deck clearance will allow you to compute the current CR and then make required adjustments to lower it as necessary if detonation was a problem.

You should also determine what caused the valve/piston interference. An OE 327/340 should not have this problem due to basic engine clearances, but head/block machining and/or aftermarket cams can leave insufficient running clearance.

Another possibility is a one-time significant overrev. Given the degree of contact I'd be surprised if the valve stem is not bent.

The pistons appear to be the OE forged type and the numbers on the bottom will likely reveal if the are the originals or OE replacements.

Duke