Rebuild Questions

[Oldsie]

I'm back to working on the Olds again, and making progress. Got the radiator support cleaned, the front frame rails are coated with rustproofing solution (and sealed inside with Eastwood's frame coating), and ready to paint. I'm getting ready to go through the 307, and freshen it up with new bearings, rings, and gaskets. I've got a couple of questions for you.

First , I need to clean up the block and heads, and am debating whether to spend the money on getting them hot tanked. The block is not sludged up, but it is dirty, and the heads have some junk in them from sitting so long. The other option I have is cleaning it up myself with cleaner (after I get all the oil galley and freeze plugs out, not to mention cam bearings). The question is, if I clean it up myself, what would be the best way to wash down the block afterwards and still prevent it from rusting? I was told that WD-40 could be sprayed on the block and in the passages to help remove the water, and then the block could be blown out. I also read in Mondello's book that you could wash the block down with hot water and Simple Green and blow it out...problem is that I don't have a hot water outlet in the garage. If I instead have the block hot tanked, what would be the best way to remove the excess residue from the block?

The next question is about honing. If I put new rings in this, I'm going to need to hone the cylinders. I've read in the book where you should use a torque plate when you do this. Unfortunately, I don't have one, nor do I have the funds to purchase one (maybe on my next build...I picked up a 71 350 2bbl with #7 heads this spring, cheap...don't think I haven't thought about using that instead, with a nice 4bbl intake on it!). Is this something I need to do? I want to get this right...been a long time since I've built an engine.

[88hurstolds]

I would have the block hot tanked to ensure that the oil passages are fully cleaned out, don't want to be wiping bearings or cam lobes.

WD40 actually will cause untreated metal to rust believe it or not... it has moisture in it.

A torque plate is for boring not honing.
You need to have a machine shop bore with a torque plate if there is a ridge at the top of the bores.

If there isn't then you can just use a hone brush / dingle berry brush to hone in a cross hatch pattern on the bores.

[Oldsie]

It's been a busy weekend. I've found out a lot of things, most not so good. Starts out, I pulled the heads from the 307, and found a lot of carbon build up on the pistons. The good thing was that the cylinders looked ok, not much of a ridge. I also noticed that the valves didn't look right. I showed them to a buddy of mine, who said both heads needed reworked. The valves are seated pretty deep in the head, not to mention two of them look different from the rest. So I put the 307 to the side, and started on the 350.

I tore the 350 down, and found one head that had a bad valve. The bearings needed replaced...they were thin enough that when I had the rods unbolted, and the first two mains off, I could move the crank up and down. I did check the main bearing journals with a caliper, and they looked to be in spec. I pulled the pistons out, and one of them had a tight wrist pin. Another had a bit of resistance, but not as bad as the one did. I'm reluctant to use that again without changing the wrist pin. I was told that they can be loosened up, but how long they would stay that way, who knows...I don't trust it. So, back to the 307.

I was going to finish checking the rest of the 307 (which is not as dirty as the 350, btw). I stumbled on something that made me stop. I read where the 307 VIN 9 was supposed to have a piston that had a horseshoe-shaped dish in it...that's not what was in mine. Here's the pic:



What kind of piston is this? Could it be that a dealer swapped in a VIN Y block? I'm going to pull the cam to check the number, but it is looking to me like they may have used the VIN 9 parts with a VIN Y block...I think they were in a hurry to get it back together. The cam does have the button and spring on it. I'll find out if the cam is right in a day or two when I get back to it.

In the meantime, I'm trying to see where to go next. If I have to have the heads redone, it's going to cost more than I have right now, not to mention the additional cost to replace the pistons to get it right. As for the 350, it looks like I would need to swap out probably two pistons, and redo or replace a head. Both options will probably run more than I have. If I could find some replacement heads at a reasonable cost, I might be able to save one or both engines.

I do have a good, running, non-smoking 350 in my 77 Cutlass, but I hate to pull that out. I've considered trying to find a good, running 403, but haven't seen one lately. I would like to get this problem solved soon, as I'm intending to have the car ready for a cruise in August, I hope.

Thanks for the help.

Oldsie

[88hurstolds]

VIN9 pistons are the same as VINY and do not have a horseshoe shape to them.
The only difference between VINY and VIN9 are the balancer, exhaust manifolds, carb and valvetrain (cam/springs).

I would just replace the rings, bearings and seals, find a pair of used heads that are still in good shape and run it if you are just looking to get the car to a driving state and put as little money into it as possible and save your money for finding a good running 350/403 to rebuild in the future.

[Oldsie]

Thanks for the help, it's much appreciated. Wonder why the aftermarket pistons all show a horseshoe shaped dish? That is really good news, because I did not want to swap out pistons right now. I'll look for a set of heads that have some good valves, and swap out the springs. As for the 350/403, I have the one 350 that could be rebuilt, but I'm kinda leaning toward finding a 403 at some point. As for the 350 in the 77, I didn't want to get into pulling that right now...I have a really bad feeling about loosening those manifold bolts. I broke two off on the other 350 when I was pulling the manifolds...both in the center of the head It's going to take a bigger torch than I have to heat them enough to get them out...it's either that, or drill them out and retap the threads.

I'll let you know what I find out on the cam when I pull it out.

[88hurstolds]

I heard that the aftermarket 307 pistons are wrong and actually have a shorter pin height I believe which means they sit further in the hole and the block needs to be decked just to get back to the stock CR.

[Oldsie]

Well, I know they certainly don't look like what I had. Even 442.com says they have the horseshoe-shaped dish...not sure where they get that info. At least the ones I have will give the correct CR. I'll stick with these.

[Oldsie]

Took the heads to a local machine shop, and let them look at them. They said the valves looked fine, and told me to put some gas or solvent in the chambers to see if they leaked (used some solvent). Only one had a drip, and that went away when I tapped lightly on the valve (probably a piece of carbon). That was good news...didn't have enough to go through the heads, too. Afterwards, I did find out a lot more about the engine:

Checked the mains and rods, and was coming up with undersize readings. I had the same shop check the crank, and it was .020 under on the mains, and .030 under on the rods. I looked at the underside of the bearings, and there was the size....020 on the mains, and .030 on the rods. Also found a date on the bearings (which, btw, were ACL bearings...just read that they're out of business). Date was 25 Apr 93 on the mains, and I think 08 May 93 on the rods. Looks like this was a reman engine he bought somewhere in the mid 90's to replace his other one.

Next thing I found was the cylinder size. I started checking the bore (all I have are snap gauges and a caliper, unfortunaely), and kept coming up with oversize bores. Did some checking, and saw where I should check the piston skirt, and also look at the top of the piston. Cleaned it off, and sure enough, all 8 have .040 stamped on them. The cylinders and pistons measured 3.8375 - 3.8385 (ex. 3.838 bore, 3.8385 piston). Looked like they were with .0005 of each other on each cylinder. Didn't see any evidence of taper or being egg-shaped either, so I think we will be ok with this. Looks like I have a 314, or something like that More cubic inches.

Getting ready to order the new bearings and the other parts. Going to take the block in as soon as the parts come in, and have it hot tanked, and new cam bushings and freeze plugs put in. Will I have to pull the oil filler tube, or can that stay? Not sure how I would get it out...

Here's a short parts list:

Main and rod bearings, and cam bushings: Clevite 77
Rings: Clevite/Perfect Circle
New lifter to replace the oddball in #1
Various hoses and other parts, including new heater valve (if I don't replace it, it will inevitably blow...been there, done that)
New oil pump and water pump

Did these engines come out with a standard oil pump, or a high volume? Also, does this require the water pump for heavy-duty cooling?

I think this will be the last go-around for this engine, as it is already getting up to its limit. I may rebuild the 350 in the future...that could be a powerhouse.

[88hurstolds]

Hmm, I could be wrong on the horseshoe design but my '85 442 engine has a circular dish.
The information on 442.com points to roller motors with 6A/7A heads and the horseshoe design promoted port velocity for the swirl port design for fuel economy.
I just know that there wasn't a difference between Y and 9.

Sounds like you have an aftermarket rebuild, does the VIN match the car?

[Oldsie]

Unfortunately, there is no VIN stamped on the block that I can see. It does have a block number that corresponds to an 87 block, "6509GM5.0L G". Found the code in the Mondello book. Could it have been a replacement block that wound up at the rebuilders, and then bored out? I'm going to go visit the original owner once the car is running. He only lives about two miles from me. I've got a lot of questions, and would like to show him how the car is coming along.

As far as the VIN numbers on the rest of the car, all numbers, from the VIN #'s written on the paperwork with the owners manual to the SPID match. Just wish it had been stamped on the block. It still looks like they used a different short block with the original heads, since the heads were black, and the block had no paint at all. I wish I knew how to decipher the tag on the side of the block.

As far as the pistons go, I'll have to go with what I have...not much money to spare. At least they look ok...the underside and skirts look clean. I think they'll work ok. If I need more power, I can rebuild the 350 that is sitting in front of the car right now...maybe in a year or two.

[Oldsie]

Need some help figuring something out. One of the lifters is slightly different than the rest.



The top lifter was in the intake valve spot on the #1 cylinder, the other one in the exhaust, same cylinder. All the remaining lifters look like the one on the bottom. The diameter and length is the same (sizes are to spec for the roller lifter), but I couldn't figure out why they looked different, until tonight. I ordered a new lifter to replace the top one, and got one exactly like it. Started looking at the lifters again, and realized that the oil bands were different. Why would one have a larger oil band than the other one? Would this cause a difference in the way the engine ran?

Is this a problem that needs to be addressed? It seems like there would be a difference in pressure, given the size of the oil bands.

Also, does it make any difference whether the oil hole points toward the front or rear of the bore? These had the holes pointing toward the front. Just want to get it right.

I'm going to also post on realoldspower...got to get a solution soon, as I am currently cleaning up parts, and will be assembling the engine very soon.

Thanks,

Oldsie

[88hurstolds]

Just saw this and the responses there.
GM did some improvements to the design of internals over the years and the fit/function are the same but looks like they may have improved on oiling.
The engine probably had a collapsed lifter at one point and was replaced.
Why they just didn't replace all of them is beyond me...