Engine oiling

[Don W.]

OK the short block is apart after a full season of racing. Prolly more than 100 passes. Anyway, at first glance everything looks good EXCEPT #2 & 3 mains and all the rod bearings.

So what I'm wondering is, short of a bowtie block, how can I improve the oiling to the center mains?

One thing I'm gonna definitely do is have the dist turned for o-rings so oil is not lost there. I'm gonna look at maybe drilling the oil hole to the mains out a bit. Another thought is 3/4 grove bearings. Maybe a heavier duty bearing?

Another thought would be to drill out the main passage from the oil pump up to the galley.

Comments appreciated, thanks.

If yur interested I can post pics of the combustion chambers, pistons, cyls, whatever. LMK

 

[turbodig]

Re: Engine oiling

What makes you so sure a lack of oil was what killed the bearings?

 

[sharkbait]

Re: Engine oiling

wouldnt rod bearing damage come from detonation?

 

[turbodig]

Re: Engine oiling

wouldnt rod bearing damage come from detonation?

Exactly. Particularly considering the main bearing damage in the middle of the crank.

 

[cloneman315]

Re: Engine oiling

x2?

 

[Don W.]

Re: Engine oiling

Well detonation is prolly the culprit and # 3 main is, by far, the worst. If I were to place a bet I'd say the rods were suffering because of the mains and there may be other issues as well.

All that aside, my question is the same. I wuz just wondering what others might have to say about improving oiling.

 

[SY2455]

Re: Engine oiling

I don't have alot of experience yet with the stock 4.3 but with a stock Oldsmobile you can use oil restricters in the block to keep the oil downstairs. The stock Oldsmobile engine can pump the oil pan dry if you run it over 5000 rpm for too long. With Oldsmobiles the oil restricters are used all the time.

 

[jwaller]

Re: Engine oiling

aside from the newest fancy billete pumps and polishing the rear main cap where the oil enters the oiling system, you are about at out of luck.

as you know the rods are the last in line for oil in the stock system so they will show bad things first. you could do a 4 bolt conversion to help with the main bearing issue but if you are getting detonation then there is no cure for that. it will kill anything you can dream up.

 

[Don W.]

Re: Engine oiling

4 bolt conversion done. Last July I got into some severe detonation and blew a head gasket. During that repair I checked and then changed the bearings. Crank was slightly damaged. Somewhat amazingly the truck raced the whole rest of the year. Now short block is completely apart for corect repairs. Oil pressure was always good.

I was posing the question because I wuz looking for others ideas if any on any improvements I might make to the stock system. Had not thought of the polish routine so can do that easy, thanks.

Will let you know what else I end up doing, if anything.

 

[sharkbait]

Re: Engine oiling

just curious, but shouldn't the alky kit keep you from detonation? or do you think you could have hurt the motor when you were not using the alky?

 

[Big Mike]

Re: Engine oiling

You can detonate if you are to rich too, just because your Afr's are good does not mean it is not detonating.

 

[TYTILIDIE]

Re: Engine oiling

These things ****ing suck!

Don, I will vouch for Wallers statement. The guy that owns the machine shop I use races 4.3's in a circle track car. He has told me that he has done everything under the sun and the poorly designed oiling system on normal 4.3's is something you WILL deal with as long as you run it.

 

[Don W.]

Re: Engine oiling

Thank you Mike, 'appreciate it.

Sharkbate; Yes normally alky will help but not stop detonation. In my case it was, I believe, combination of alky not set right, to much initial advance, 91 octane, and an over boost. Add it up and I guess I'm happy the bottom end stayed together.

I'll stick up some pics to show more of what I'm taking about.

 

[blk00z28]

Re: Engine oiling

The guy that owns the machine shop I use races 4.3's in a circle track car. He has told me that he has done everything under the sun and the poorly designed oiling system on normal 4.3's is something you WILL deal with as long as you run it.

Just wondering here, is this guy running a wet or dry system? I would think if you're going circle you'd go dry sump.. If he has, he's really getting bad oiling still?

 

[bogey317]

Re: Engine oiling

The reason the center bearings wear is due to flexing/bending of the crank, thats why the the stock clearance is so tight.

 

[It's just a six]

Re: Engine oiling

Is there lifters that will restrict oil to the rocker arms & therefore force more oil through the rod & main bearings?

For the most part SBC's get too much oil to the top end & for racing,sometimes you would use retricted lifters.
Not sure if that is available for these roller lifters?

BTW,what was you best time this season?

 

[Don W.]

Re: Engine oiling

I'd have to check but 4.3 oiling system is different. I don't think restrictors will work. Most of the restrictors I've seen say don't use with hyd lifters anyway

Best times this year were 11.6 @ 116.5

Here's some pics:

Rods bearing (all the same):

Piston skirt (all the same):

Center mains, lower shells:

 

[It's just a six]

Re: Engine oiling

Looks like the bearings are taking a good pounding.

Plus possibly some debree flowing through the oil system?

11.6 is nice! GOOD MPH also!

 

[turboj91]

Re: Engine oiling

Plus possibly some debree flowing through the oil system?

Have to agree with debris in the system. Lots of bearing damage but I'm not seeing the discoloration and wear patterns usually associated with oil starvation.

IIRC, the engine was apart before. Was there a bearing issue at that time?