Engine Builder Advice
 

Hello to whomever sees this. I'm not a pro. Been turning wrenches for 45 years, but never for money. I try to do everything myself to my classics. If I hit a brick wall then it's time to learn! I got a 69 GTO that is a nice car. Pulled the original engine because it was leaking bad out the ass. Was running great otherwise. Tore it apart because, hey, it's 50 years old and I had few records of it's past. Sent the block & heads out to the machine shop. Paid handsomely to get it checked out. Returned to me with a bead hone job, cleaned mapped and crank polished, heads done. Cam bearings installed. They could find nothing wrong with it.

I put new chrome rings in it and 10 over main and rod bearings. Ring gap set at a generous .018--carefully one at a time. Everything was already stamped to match, so I feel parts aren't mixed. Triple checked everything. Plastigauged main bearings -- looked perfect. I took my time.

Engine is beautiful and ready for install, but it takes 60 lb ft to turn it over everything tight and plugs out. Loosened all of the bearings and it went to 50 lb ft. (I even bought a fancy new torque wrench for this project. (Checked it against a friend's). Makes little difference if I loosen up valve train. GTO club told me this forum is where the black belts hang out, so I'm shooting up a distress signal. I think the resistance is excessive, but don't know anyone with more real experience at building old GM. Lots of advice all over the map from the gallery that I don't trust. Your thoughts?:drive:

Related. the topic discussed here:

"Speaking in terms of just the short block I have always use 25 ft lbs as a guide AFTER breakaway to keep the rotating mass spinning with a new rope seal."

"A stock shortblock should take around 35 ft. lbs. to break free and turn over. With the right rings and rear seal I have gotten them down as low as 16 ft. lbs. on a Pontiac 400. With valvetrain hooked up, i would think it might ad 15-20 ft. lbs."

https://forums.maxperformanceinc.com....php?p=4969424


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8 slugs ball honed in are worth 22 to 40 ft-Lb TQ wrench effort

Crank rear Seal is worth 5-7 (silicone/ neoprene) and more for new rope. Front seal worth a 2-3 Ft-LB, but that would presume the Timing chain is on which the Cam may resistive.

It is the#4 Main Cap to be keen on if it adds TQ wrench effort.

So tighten 1 bearing cap at a time, check TQ wrench to reveal if you got a tight Bearing.

OK. I have to ask you some questions to make sure we are on the same page on everything. You mentioned you used your torque wrench and then a friends to verify. Are we talking "click" type torque wrenches or beam style with a needle? I can see an engine put together with a rope seal and high tension oil rings, and assembly lube, especially assembly grease, taking 50-55 lbs. breakaway torque to rotate. I don't like it, but I believe it. If we are talking true rotating torque with a beam, needle torque wrench, that's too tight IMO. Some concern about your hone job and piston rings as well. You said they gave it a "bead hone job"? Not sure what that is, but if you mean a ball hone or dingle ball hone job, that is not a professional way to hone cylinders, that is a backyard method. If it was just ball honed, then chrome rings are a really bad choice for piston rings. Chrome faced rings are very hard and smooth and do not conform well to the random and rough surface produced by a ball hone. The engine will likely burn oil and smoke some and take a very long time to break-in, if at all. A much better choice would be the cheapest, soft iron rings available, like Hastings plain iron rings. They break-in fast and will conform better to the irregular walls left by a ball hone. Limited life expectancy though, 60-80K miles if lucky. If you want, PM me. I am not far away and I probably know all the engine shops in the Columbus Ohio area. Good luck with it . Fill in the blanks and I will be happy to help.

If the heads are on the motor I would pull them and then check to see if you are seeing scratches in the cylinder walls left by the ring ends, and yes even the oil ring rails!

And not to bust Balls but to inform,there is no such thing as chrome moly rings, that’s a type of steel.
Rings are either plain cast iron face, moly ( plasma moly) face, or chrome .
The Chrome face rings need a ruff wall finish to break in and this can take a long time to happen and causes high engine temps and puts a bunch of fine cast iron into the motor, so yes not good!

My thoughts as well, Mike. Chrome faced rings are fine in dusty conditions for Diesel engines and for steel cylinders in aircraft engines but there are far better and longer lasting alternatives for street engines. My question to the OP: why go to the expense of having the heads and crank checked out but not the block?

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Sounds like the rods are in backwards.

I’m less than 2 hours north of you in Findlay I could check it out and run it on the test stand before you put it in the car.

Seems like a lot to us, too
 

As mentioned:

Check for rods backwards.

Loosen mains and tighten one-at-a-time. Especially #4

Verify that the pistons are in the correct holes.

Don't forget that the front cylinder is actually #2.

Sometimes the simple stuff trips us up.

Good luck!

Did the cut the crank undersize or just “polished”?

What are you bearing clearances?

How much thrust end clearance do you have for the crank?

With Chrome rings you MUST break in correctly AND keep running the engine for a while, maybe couple months with 2-3 times a week starts and warm up and various rpm.
If you just "seat" the rings and pack it for winter, you'll be smoking next summer.

Chrome rings and a ball hone ? Asking to be a smoker.

Middle age eyes without the glasses.

If the crank was just polished and not turned to 10 under I would be surprised that the plastigage would show proper clearance with 10 under bearings. I would expect it to show very tight.

Thank You for all the comments! My reply to questions:
 

These comments are great. I'm making a list of things to review. Funny how shining a bright light on something brings out room for error. I'm using click torque wrenches. Borrowed a very nice one from a GM Certified friend to check accuracy of mine to be sure. That 60 foot pounds is the breakaway torque. To be sure it's a little less once going. Engine does not have a rope seal. I installed the BOP one piece instead. A little tight, but I could turn the crank with one hand.
Machine shop told me to use 10 over crank bearings, and I did plastigage to .003.
Rod bearings had 10 over stamped on the back, so used identical replacement.
The machine shop did the bead hone job to clean up. Did not bore the cylinders. New rings were gapped to .018 individually. I pulled the paperwork from Sealed Power for E299K rings that are not chrome, but iron with top ring moly coated, second ring iron and the oil rings stainless. I've turned the motor quite a bit by hand. Took out the pan and windage tray and oil pump to look inside. No sign of even the slightest scratch in any of the cylinders. Have been loosening bearing one by one and checking rotation for a smoking gun without result. Pistons all had a notch that coincided with the Rod ID boss facing forward on holes 2,4,6,8. and facing opposite on 1,3,5,7 (from 69 Motors Manual).
I'm not mistake proof by a long shot. So I'm re tracing every step. Some people watch TV, play with phones or put puzzles together. This is how I keep my mind busy! Thank you for your comments.

I'm Glad you do NOT have Chrome rings. Sounds like tolerances are snug, but make sure you use good oil.
New engines have tight tolerances. Youll be good.
I was/am a certified GM tech from the later 70's and I built, rebuilt plenty of engines with a Beam TQ wrench.
Now we have a stretch %, but unless you are crazy radical, youll be good with a clicker, or beam.
Good luck!

I had a 455 rebuilt and it was always hard to turn over. Eventually I took it apart and another machine shop found that the camshaft was not straight. Not way off but enough to cause excessive drag.

Just my thoughts, I had exact same situation with my 455 many years ago. All bearing clearances where perfect, everything installed correctly just like you are saying. Drove me crazy that the breakaway torque was 60. The engine ran fine but always hot. I eventually figured out that it needed a align hone. Just loosening one bearing at a time didn’t make much difference, it was the combination of bearings all together contributing. Once aligned hone breakaway went way down.