engine rebore

[Noel K.]

I purchased a frame off restored numbers matching '65 roadster approx 6 months ago from a recognized mid-year dealer. Having driven the car less than 1000 miles since purchased, I have just noticed white smoke coming from the left tail pipe. Assuming I either had a blown head gasket or a cracked head, I had my mechanic pull the heads.

I now wish my first guess was correct. I have discovered that when the engine was rebuilt approx 3 years ago the engine was bored .060 over. When the engine was put back together the No 7 cylinder piston pin was not installed properly and the pin has worn a groove in the cylinder wall, to the extent the water jacket is now compromised and the cylinder is pulling antifreeze causing the white smoke.

Any thougts about how/if the cylinder(s) can be be resleeved or other suggestions would be greatly appreciated. My mechanic is doubtful the cylinder can be resleeved because of the depth of the groove and the fact the cylinder has been already been bored to .060 over. If this is not possible, I will no longer have the correct numbers matching block for my car and am left with a nice "driver" and a diminished value of at least $15,000. Certainly not what I anticipated when I purchased my first mid-year !

I live in Central Indiana.

Thanking all in advance

Noel Kendall

[lyndon sharpton]

Re: engine rebore

I would think that you could save you block for less than $15,000. that is the great thing about sleeving. is for a block that has a deep groove in them. you can save that block. find you a good machine shop that has resleeved some blocks an talk to them. tell them that you want to save your # matching block.good luck!

[Bryan L.]

Re: engine rebore

I agree, you should be able to sleeve it and save the block. Plus you don't have to deck the block just for 1 sleeve. You might try emailing Clem Zahrobsky who is a regular here. He used to build engines and could give you some ideas about how to find the right machinist.

BL

[mike mccagh]

Re: engine rebore

block almost certainly salvagable. just make sure the machine shop does not run their rotary broach across the engine pad. if they do so, it'll be akin to your gradmaw getin one of her mammary glands caught in the ole maytag ringer washer.mike

[Mark #28455]

Re: engine rebore

If the pin wore a groove in the block, then it neither extends to the deck surface nor to the bottom of the bore so the sleeve should still seal well at the top and bottom of the bore. I have used sleeves in my racing engines after blowing a huge hole through the wall (1" x 3") and they still held up well.
Good luck,
Mark

[Bill Farmer]

Re: engine rebore

Noel,
I can certainly feel your pain. I bought a 66 matching big block coupe, drove it for 2 weeks (a few times) dropped a valve, punched a hole in the piston and the head, and scored #5 cylinder wall. The engine was already bored 100 over. After asking on here and calling 20 corvette folks, the concensus was: it could go 125 over (is your car a small block? maybe different for sb). So, we are sleeving #5, they are able to fix the head as well. I don't know the grand total yet but the engine builder says 5K should be close. One good point for both of us, our engines are screwed up on the drivers side....so our engine pads are safe! Good luck let me know how it comes out. Bill

[Michael H.]

Re: engine rebore

That's a sad big block experience but it happens all to often. For anyone that purchases an early big block, I STRONGLY recommend trailering the car home for immediate replacement of all of the valve springs, retainers and locks. These early 1st design parts have been consuming big blocks for 40 years. The latest GM springs and retainers are quite durable and you won't have any problem with them. I don't have a newer parts book handy for the current GM numbers but I'm sure Joe Lucia can provide that if needed.

[mike cobine]

Re: engine rebore

I'd begin shopping machine shops. I'd hit the local cruise-in for the next few weeks and find who is impressed with which machine shop. This is a one-shot deal, so you have to have the right guy.

If that doesn't pop up something, then I'd hit Indianapolis Raceway Park and check with every drag racer and every circle track racer you can find on who does the best machine work.

Then go talk to them with your block and see what happens.

For $15,000, you can afford to drive a few miles, buy a few burgers, and supply a few drinks in exchange for information.

Didn't you notice massive oil consumption and blow-by? My Suburban broke a ring landing and cut a groove like that and it began immediately blowing back out the valve cover vent and using oil like a big block. The blow-by out of the vent covered the underside of my hood.

[Bryan L.]

Re: engine rebore

That's a good point about changing out the valve springs and retainers. I now intend on doing that before I fire up my fresh 427 which happens to have original GM valvetrain pieces.

BL

[Michael H.]

Re: engine rebore

Bryan,

I well remember all of the brand new 65-67 big block Corvettes (and Chevelles etc) that lost their original blocks in the first few weeks of their life. Typically, when a valve spring or retainer fails, the valve is dropped into the cylinder at a very bad time in the cycle. The head of the valve usually breaks off and is trapped between the rising piston and head. The result is usually a cracked head, at least one crack in the cyl wall, a bent rod and a bent crankshaft. All of this can happen even at low RPM. Far more big blocks departed this earth because of valve problems, in the 60's, than connecting rod failures. New springs and retainers are a cheap insurance policy.

The springs with the single fat wire and flat coil dampner are the dangerous ones. The latest GM springs have two separate coils, inner and outer, with a flat coil dampner. Dampener? Dampnr? Hey Duke, how's that go again?

Michael

[Noel K.]

Re: engine rebore

Thanks all for the suggestions. After copious amounts of medicinal Crown Royal I can now vocalize short monosyllabic sentences and will hopefully be able to convey the issue to local machine shops.

I have a client who is a team mechanic on a Indy racing car team and think I will give him a call. I also have another friend who is a recognized expert on Mustang restoration (I know, the ugly FORD word ) and will probably give him a call.

I contacted the dealer I purhased the car from( that is several states distant ) and informed him of the problem. He commented that as he did not rebuild the engine he could not warranty it. However, he has offered to perform the repairs on a 5/0/50 basis meaning he will split the cost of labor and parts but I will have to get the car to him. (I would think I could get this the block alone as an alternative to transporting the car so we'll see) The mechanic that is working on the car is a 30 year friend that is an ASCI(?)certified technician and I have complete trust in him. He has also said he "would take it easy" on me regarding the cost - so I will have to consider the dealer's offer and weigh his repair (estimate) once received compared to having the engine rebuilt here. In fairness to the dealer, it certainly appears this engine was rebuilt improperly and this issue has continued to develop from day one of the rebuild. Just my misfortune to have it the eventual demise occur after my purchase !

The heads seem to be fine - the valve guides have minimal wear, the valves are all in good shape and seating properly so I don't think I am going to have any repair issues there.

If the block can be resleeved, will it be best/required to have all the cylinders sleeved and replace the pistons, rods, pins, etc. ? I am assuming, at this point, the crank is fine as well as the camshaft. No other problems seem apparent upon initial review.

The car did not overheat nor exhibit any oil burning. We did discover the antifreeze volume was probably below one gallon - but the overflow tank still had fluid in it which is curious. The first indication was approx. a week ago when the car would not always remain at idle after being warmed up- certainly because of the fluid in the cylinder, I'm sure, and effectively running on seven instead of eight.

I will contiune the search tomorrow - and will keep all informed of the continuing saga. Thanks all for comments, reassurance, and suggestions.

Noel Kendall

[Robert Willis]

Re: engine rebore

Just sleave it. This was a problem on the 366 and 427 truck engines and I used sleaves with no problems at all. The steel in the sleave will be better than the original cast iron wall.

Bob .

[Duke W.]

It's DAMPER! *NM*

[Dave McDufford]

Re: engine rebore

Noel,

BES Engines in West Harrison, Indiana (near Cincinnati) does a nice job with engine machine work. I watched them resleave an expensive racing block that had a number of holes in it. They did all the machine work on my matching numbers engine - I did the assembly. I took it there after talking to a number of people in speed shops around Cincinnati.

It is owned and run by Tony Bischoff who is a first class individual. His web site is below.

Dave

http://www.besracing.com/index.html

[Joe L.]

Re: engine rebore

Noel----

You have used the term "resleeved" several times. This implies the engine has been previously sleeved; is this actually the case? If it's 0.060" over now, I really doubt that it was ever sleeved. Regardless, though, it can easily be sleeved (or, resleeved).

As far as whether to sleeve all 8 cylinders, there are "pros" and "cons" of doing that. One of the "cons" is that it will be expensive. Another "con" is that when sleeving is done, the top of the sleeve has to be machined to ensure that the sleeve is absolutely flush with the block. Performed VERY carefully, though, this should not cause any problems with stamp pad broach marks. MAKE SURE THAT THE MACHINEST IS AWARE OF THIS CONCERN, THOUGH.

On the "pro" side, by sleeving, you can get the engine back to standard bore. At 0.060" over, you are pretty much "maxed out" as far as a RELIABLE overbore is concerned (assuming the engine is a small block). So, if the engine is rebuilt again and requires boring, you'll need to sleeve all the cylinders, anyway. If you sleeve just one now, that one will have to be overbored to the same bore size as the rest of the cylinders. This means that if and when you need to sleeve the whole engine, you'll need to resleeve this cylinder.

Another "pro" here is that by sleeving the entire engine, you'll, basically, "erase" ALL of the previous work of whatever klutz worked on this engine the last time. You've already discovered one of the results of his "handiwork"; who knows what other manifestations are yet to be revealed?

On balance, though, I think that just sleeving the one bad cylinder is probably the way to go, for now. Considering the kind of mileage that these cars usually get, the engine may never need another rebuild IF IT'S DONE RIGHT THIS TIME.

It's hard to imagine someone getting a piston pin so improperly installed that it contacted the cylinder wall. Likely, the rod small end did not have the proper interference fit and the pin "worked its way out". Most small block Chevrolets with only a few minor exceptions used pressed fit piston pins which require no piston pin retainers. However, the interference fit of the pin in the rod small end bore has to be right or this method of pin retention won't work. If, by some chance, the "klutz" installed floating pin rods with retainers (like Spirolok), I recommend that you convert back to pressed pin type. I'm not a "floating pin guy"; they work ok for racing applications but I feel that pressed pin are the best for street operation and that's what your engine originally used (and may still use, as I say).

If I were you, while I might just sleeve the one bore, I'd go through the whole engine to make sure the rest of it's right. I would have ABSOLUTELY NO CONFIDENCE, AT ALL, that the previous "engine builder" knew what he was doing. If you send the car back to the dealer for repair, you're likely to get nothing more than the repair of this one cylinder. That would not be enough for me in a case like this.

Also, I think that I'd replace all of the pistons and, especially, all of the rods. At this point, I think that I'd use NEW, high-quality aftermarket rods. Not the "super high dollar" racing type rods; just a high quality set of NEW street rods. You might want to check with Howards Racing Products in this regard. They are supposed to be coming out with forged powder metal rods for small journal small block applications. If they've got them out, that's EXACTLY what I'd use. They'll be relatively economical and they'll be FAR stronger than anything you're ever going to need.