hudman

A friend and I went to a Vette Rally about an hour outside of town today. It was cold, but sunny, so we thought we would have some fun. Rally started and we went off third. My friend cant follow directions at all, and we immediately missed a few turns. I was working the car pretty hard to catch up and punched it in 4th to pass a Cadillac. I ran the car up from 50-80 or so and heard a bad knocking noise. I thought I was dreaming it (a nightmare actually) but no such luck. We pull the car over and sure enough, something major has gone wrong. There is definitely a very noticeable knocking going on inside the engine. We called a roll back and headed for home.

The car is now at my mechanics. I am somewhat perplexed because a year ago the motor received a new valvetrain and cam, and just several months ago the oil pump gave out and the bottom end was pulled off and checked. The Plasti-gauge showed that all rod caps and main caps were in tolerance and none of them had any scoring to deal with. So who knows. All I know is the car is laid up and I am facing a huge bill.

If it is terminal, what do you guys think about going with a ZZ502. My mechanic has a slightly used one available for @$5000. Can I get that under the stock hood with a manifold adjustment. The original appearance is important to me and I do not want to go with an L88 hood. I have to believe that they may be a better route and just crate this motor and fix it later. I like the idea of a period correct 427, but my car is not matching numbers anyway. Is this a bolt in situation, or will a lot of work need to be done to get everything to work.


[Modified by hudman, 3:17 AM 1/12/2003]

mapman

hudman,

How long can you wait?

The 2003 GM Performance Parts Catalog shows a Vortec 496 cu inch, 525 HP / 560 Ft Lbs, port fuel injected motor available in late 2003 the "HP3 8100".

Also available in late 2003, the "ZZ572/620". Tall single plane intake manifold with 850 cfm Demon carburetor - 620 HP / 650 ft lbs. 9.6 to 1 compression ratio.

PB82CE

:mad :mad :mad :banghead: :banghead: :cuss :cuss :cuss

'79ProwlerOrange

but those are both going to be way more than 5K. id buy his motor and stick the 427 in storage and plan to make it a builder.

JoeC427

:iagree:

Solidlifters

I assume your car is a big block now. The ZZ502 will require an aftermarket intake, or whatever's on your car now. The alum. heads on the ZZ502 are oval port, rather than rectangle like all GM's other alum BB heads. The short waterpump from your present engine should bolt on also. With the ZZ's one piece rear seal, the pan from your present engine won't interchange, but the one with the new engine should fit. Also, there's no provision for a fuel pump on the ones I've seen (although the newest Mk VI blocks apparently have em again). I can't think of any other issues except for the loss of performance from losing the ZZ's intake.

As far as GM's new engines for 2003, the grandaddy will be the new 572 cu in crate motor, available in either 610 horse for pump gas or 710 race gas. It should become available any day now. For those people that haven't seen it, here's a link: http://www.sallee-chevrolet.com/Sneak/Previews.html

Chuck Harmon

Hudman,

I think I might question the true condition of the "slightly" used ZZ502 if this is the same mechanic that gave you a clean bill of health on your motor earlier. $5000 is a lot of money to lose if you later find that you should have bought a new one in the crate instead.

If nothing let lose, you may be quite a bit ahead of the game to have a proven engine builder (perhaps your mechanic is one, or maybe not) rebuild yours with higher grade parts, especially if it is not the original anyway. do you really want another engine lying around the garage taking up space. They are too tall to fit under the bed, I know, I've tried!

Chuck

Larry B.

With the 68-72 C3 BB's you MUST use the stock Corvette sunken intake and the correct drop base air cleaner or the hood won't close The stock manifold won't work on heads with bigger ports so your choices are limited.

Love My 72 and 77

Hudbud,
Take the time to get your original moor rebuilt correctly. you can't always trust mechanics talk to people around your town see what they have to say about other machine shops and mechanics. Drop your current mechanic if he is the one that has been taking your money to stick parts in your motor. The bad news is you will have to spend money to do a complete rebuild but the good news is you will have a completely fresh motor you can depend on. I would think you could get your motor rebuilt very nicely for under $5000 even if you had to ship it to a reputable engine builder.

Marks69BB

Hey man that sux! Hope it's not something that trashed the block!

If it were me, I'd get in touch with John West in Raleigh who is the man for :chevy big blocks. If you're going to spend the $s, get someone who knows them and has the rep to back it up. Let me know if there is anything I can do to help. Good luck with it.

72rdstr

Just my two cents here...
A "slightly" used 502 will need rings at the very least. They come with very "loose" rings and burn a little when new and it only gets worse (see SD's site for more info). Additionally, you'll have to install an electric fuel pump for the 502, they DO NOT have a fitting for the mechanicla pump.
It would probably be much cheaper to do a quality rebuild on your current engine.
Just my opinion.
Todd

hudman

I think I have decided to stick with what I have and either repair or rebuild depending on what I find out is the problem. I just do not want to deal with all of the headaches associated with the hood clearance problems etc. At least I know that what I have fits. It may not run worth a s**t, but it fits in the car.

'79ProwlerOrange

A 502 should be exactly the same physical size wise. so it would sit the same a the 427. my rebuild on a 427 would cost waaaaaay for than $5000, but then im a power-nut. i think you could probably get yours rebuilt for a little less than 5K if you do everything stock, or only mildy increase performance. my mild rebuild on my 350 was about 3K, but i got some really good parts. a big block is much more expensive to build though.

8T1-7T9 BIONIC VETTE

Does anyone have a cost for the 572 ci 610 HP GM big Block yet? :seeya Cappy

MikeC

From the noise you describe it sounds like a spun bearing. Hopefullly you haven't chewed up your crank too much like I did my my 350 this fall.

I would question the condition of the 502 unless he's willing to warranty it :lol: