ROBZ442

I spun a rod bearing in my 66 442. I am running the original engine that was rebuilt in the fall of 2009. At that time I had the motor line honed, bored .040 and balanced. When the bearing spun I was at the drag strip and lost oil pressure in the shutdown area. The motor was making noise on the return road, I took it back and loaded it up right away and only ran it long enough to get it off the trailer and in the garage. Total run time about 10 minutes, the motor never knocked it just squeaked like a loose belt. When it was pulled apart the main bearings looked fine but a couple rod bearings were spun.The question I have is should I have the block line honed and the cylinders honed? The motor only had 3,000 miles on it since being rebuilt with all machine work and balancing.

Run to Rund

Block is probably OK. Get a true machinist's straightedge and you can lay it across the main saddles and verify that a .0015" feeler gauge has heavy drag pulling it out from any main. If nothing scratched the bores, just have the shop lightly re-hone them for new rings. Check piston skirts for bits of metal embedded. Flush all oil passages thoroughly.

rustyroger

I suggest you replace the main bearings as a matter of course, but more importantly check the rods as they may need resizing, also check the crankpins for damage. The cylinder bores are unlikely to have suffered though.
More importantly, why did you lose oil pressure on the shutdown run?, was it oil surge perhaps?, maybe you need baffles in the oil pan if you frequent the strip.

ROBZ442

I should have mentioned the block is at the machine shop, this was included on the quote. I was just "suprised" (is a good word to use) at the price to repair an engine that I just had redone. I know that it's probably the right thing to do and it's not cheap to play with Oldsmobiles but i just wanted to see what others thoughts are.

ROBZ442

I'm completely rebuilding the engine and it did damage a couple wrist pins as well.

I had a couple of problems with my engine. One was I had a 455 Harmonic balancer with it 400 timing tab, I did not know that they were different. The motor was balanced wit the 455 balancer. The other problem was my oil pan was too small. That is being corrected with a 7 quart pan and a bigger pick up tube.

I have had my car for 27 years but just started racing it 3 years ago and it has been an expensive learning curve. But it sure is fun!

507OLDS

If the motor was balanced with the 455 balancer,and that same balancer was installed,then the balancer should not be an issue.How was your oil pan too small? There are guys running low-10's/high-9's with a stock oil pan.Nothing wrong with the extra capacity though.I'd be more curious as to what the clearances were on the bearings.If they were on the tight side,it will fail every time.The oil acts as a cushion between the rod bearing,and the crank.If you make that clearance too tight,you take away that cushion,and it will eat itself.At the same time,you don't want the side clearances too loose,as this will give the oil a place to flow out of,which will also result in bad lubrication,and failure.

ROBZ442

My original question came from the quote I received for my engine. I was hoping to get some information before talking to the machine shop. After talking to the machine shop I found out that the quote was a worst case scenario. If everything checks out it will not be line honed.

The rod bearings were .003 and the mains were .004 with side clearance on the rods at .016-.018 and I have restrictors between the crank and cam.

The issue with the balancer was that the timing marks are off by 15 degrees between the 455 and the 400. By using the timing tab off the 400 with the balancer off the 455 my timing was 15 degrees retarded from what the tab was showing.

I think the real problem was being retarded it put more pressure on the wrist pins which started to sieze and that put pressure on the crank which pushed the oil out of the bearings, (or something like that). Some of it may have been from a stock pan with a high volume pump but I'm sure that a 50 HP shot of nitrous didn't help at all.

For the next round I am keeping the engine the same as before with 10:5 to compression, a voodoo 60802 cam, roller rockers, B heads and a Torker intake

Upgrades are a 7 quart pan with 5/8 pick up for extra capacity, a 750 DP with a 150 gph fuel pump for the engine and a seperate fuel system with a holley blue pump for the nitrous system.

All I am looking for is a fun street car that I can take to the track a few times a year not to go as fast as possible. I am running an M-21 with 3:91 gears and don't want to get too crazy with nitrous. I have a NOS controller so I can regulate the nitrous without shocking the system too bad on start up. So far I have only sprayed the 50HP jets but will not be running anything bigger than 100HP.

Hopefully I get it right this time.

cutlassefi

I believe you have a few issues here. 15 degrees retarded would make a significant dent in your performance. But I also have to ask why such a small cam for 10.5:1, a Torker and 3.91 gears? And with that cam and 10.5:1 maybe you couldn't run much more timing, what gas are you running?

Having retarded timing builds heat, if you have beat up wrist pins as well that's a sign of not enough clearance, excessive heat (from detonation, or even from retared timing), or it could also be a "light" balance. But normally retarded timing in and of itself won't cause wrist pins to seize, if there's enough clearence.

Your guy needs to go thru everything and double check the wrist pin clearance. If the pins got tight for some reason that's harder on the rod bearings as you said, could make them spin. While you're degreeing the cam you might also want to do a true tdc and check to make sure your timing tab is correct.

Just an FYI, I got a set of KB 886 Icon pistons, they advertise that they are already pin fit. Guess what, they weren't, in fact only had .0002 clearence. We opened them up to .0008, I'm sure they would have seized otherwise.

507OLDS

In addition to what Mark said,there isn't a single part that you can take out of the box & assume it's right,eventhough the manufacturur will talk it up that way.How else are they going to sell it.
That much timing retard would show a significant decrease in performance.The steeper gears might have helped disguise that.

ROBZ442

I think you hit it on the head with: excessive heat (from detonation, or even from retared timing) + nitrous. I ran the motor on the street for the summer of 09 and 10 and it would run hot with an oil temp of 220-230 at a stand still. I forgot to mention that I put a sandwich style oil cooler on it as well, I found out later that was not a good idea.

I agree that the cam is too small. This is the cam that was recommended because the car is my daily driver from April to November. I was looking at the Comp Cams 284 extreme originally. I am open to suggestions.

The engine was machined and assembled by Rocket Racing I got it as a short block. It worked great on the street other than being a little sluggish but like 507 said the 4 speed and gears hid that pretty well. The first time around he installed new pistons and fit them to the wrist pins, this time he is replacing the wrist pins and fitting them again to the pistons.

Like I had mentioned before I think the engine was assembled properly. I just had a poorly executed set up. I killed the oiling system with the cooler and choked the engine with a carb that was too small and a fuel system that could not handle the demand.

If I would have found this site sooner I could have saved a lot of cash.

Thanks for the help and comments

cutlassefi

Rob, you can use a .984 Chrysler pin in the event your pin bosses are scored or the like. Again I would recommend every bit of .0008 clearance in the pin bores.

Have you ever thought of going with a hyd. roller? Don't know what the rest of your valvetrain consists of but it's a viable option.

Run to Rund

Rocket Racing knows Oldsmobiles. This time, be sure to run all the parts of your setup by them and get advice. I agree with the above posts that you need more cam with the high compression to avoid detonation, and probably should run race gas like Rockett 100 unleaded (hardened valve seats) or some Rockett 111 (leaded, for old iron heads without seats). I am nervous about the pistons, pins, and rods given the problems you had. Definitely have .0008" or even up to .0010" clearance.

Nitrous is very hard on the parts, and if the engine leans out from that extra oxygen, you will ruin the engine. IMO, you would be a lot better off with a good gas-only buildup with a real camshaft to make the power, instead of a 98 luxury sedan engine with nitrous.

BIGJERR

Just my .02 but machine work is the same for all engines.......Good machine work will pay for it self in the long run........As you have found out so did I .............Jerr

My combo works real well for what it is.......Nothing fancy just a good blend of parts and solid machine work in a motor that wasnt supposed to live this long.....

ROBZ442

John is going through all of the pistons, pins, and rods, he has the same concerns you mentioned.

The nitrous is something I've always wanted but it may end up on ebay by the time it's all over. If I would have known about the cam that would have been changed as well. If I can afford it I may try and sneak one(the wife's catching onto the one more part thing already)into the rebuild.

ROBZ442

I've seen your car and love it. Thats the type of set up I'm looking for something fun and reliable. I won't be as fast as yours but my main goal is a fun car that can go anywhere. I spent a lot of time talking with John this time and feel like I will have a combo that should hold up to what I want to use it for. I think if I would have spent the time talking to John the first time I would be buying a new interior this winter instead of rebuilding my engine again.

Rickman48

There could be other reasons for no oil pressure in the shutdown area -
High-pressure pump filling the valve covers,
Incorrect pick-up depth to pump, [is it fastened in place?]
Fram oil filter,
All problems we've had!

Rickman48

We've also had RR do some work for us, when his Dad was first diagnosed with 'C'.
Took awhile to get parts back, but very good work.
Question I have; did he suggest align honing?
If it was just done, and no mains spun, he shoud be abe to check if it's really needed!
Have him look at your old receipt to 'refresh his memory' on what's been done - he's a busy guy!!

ROBZ442

I asked him about that and a couple other things but it was just quoted as worst case, he is going to check it first, same with the cylinders. I have had my engine there since October shortly after that his dad had started to have complications. I talked to him on Friday and my engine should be ready by the end of the month. I can't wait to get it back together and running.

As for your other comments I was using a Fram filter and did not check the pick up tube depth on the pan. Those are a couple things that I am chaulking up to rookie mistakes. I know its an issue but not sure how big of an issue, is there a good way to help get the oil out of the valve covers?

MN71W30

What did it turned for a time? Was there a big difference when you hit the gas? Just curious. Good luck with the rebuild.

Rickman48

Cast iron and steel tubing expand and contract at different rates, hence the necessity to weld or solder the pickup to the pump! Also in the right position!
We used modeling clay to set 1/2 to 3/4" from the bottom of the pan, with the gasket. Might check with RR on that figure.
Same error was made recenty, and you could turn the pickup with about 2 oz. of pressure, which is a big mistake!! Almost fell off!!
If you've restrictors in the motor, it's unikley you had all the oil up top!

ROBZ442

So far my times have been fairly slow. I have only been down the track 8 times. My best without nitrous was 14.4, with nitrous it was 14.0. This was with a 725 vacuum secondary carb and a missed gear. I've been told that by changing the carb and timing and fuel system I should be running much faster this year. I am hoping to run in the low 13's, that would make me very happy.

ROBZ442

I was using a bolt on pick up tube but didn't think to check the clearance.

Red71

"Some of it may have been from a stock pan with a high volume pump"

I would bet (from experience) this is the major of the problem.
these do NOT mix well at all. I would also bet John didn't know this was the set up you
intended to use.


"but I'm sure that a 50 HP shot of nitrous didn't help at all"
.... you should be able to throw a 100 shot at that and not hurt anything.

I emptied a 10lbs bottle last year in one day at the track. It was a 100 shot
of N.O.S. on a 455 w/ factory stock engine. the only thing I did was 8qt pan
and HV pump,headers and performer intake ,a Q-jet carb. 13.5s off the bottle and 12.53
on the bottle.

ROBZ442

John did not know about the pump and pan set up, and that was one of the first things he asked when I called him.

I'm glad to hear the nitrous worked out for you, my plan is to run 100 shot once everything sorted out. My set up was ready for nitrous and I should have waited but, I just wanted to try it. Next time around I will wait until things are working better.

Your set up is similar to what I am shooting for nothing to serious but effective. I would be very happy running the times that you are and think with practice I can.

Thanks for the encouragement.

Texas Jim

Was that time at the track(when the engine went south) the first time you beat the engine that hard? My reason f/ asking is that if your high volume pump really drained the pan and inturn caused the drop in pressure which resulted in the internal damage, you'd have seen that happen the first time you beat the car that hard. Years back, I had a '69 SS Nova, blew up the original 396 and then installed a brand new factory 402ci. I installed a Moroso high volume oil pump, when I initally cranked the engine, the pressure was about 85psi and after afew minutes it dropped to zero. I let the car sit f/ about ten minutes, and started it again and the same thing happened. My point is, it wouldn't have taken a number of times at the track before this occured. It would happen each and every time the same way.

ROBZ442

This was the first time I had beat the car that hard. I have always run through first gear into second hard, but never stood into it up to 100mph. On the street running through first and second it was fine. The night the engine went I had made four passes before that with about 20 minutes between rounds. The last run it was about 5 minutes between passes, that may have made a difference.

When I unloaded the car the motor ran fine with no noise but the damage was done and the oil pressure had dropped about 10psi.