Mixing bearings for clearance

[Rich Biebel]

Another piece of advice........ditch the oil accumulator......I really see no reason for one on a stocker unless your playing with very low oil in the pan or it is doing giant wheelstands.......Makes no sense to have one on a car like this to me for the little gain you might get. If you had one on there and were having oil pressure loss issues....something was definately plumbed wrong....

I have one on my dragster (3 qt Moroso) and it has at times shown some erratic operation on the pressure gauge.....I believe it was from mounting clamps that were to tight and in locations on the can that could restrict the pistons movement......I took it off and moved the clamps to the outer ends of the can but have not put it back on to see if it's fixed......

I have no knowledge or experience with the oil system on one of these Mopar engines and as I recall Mopars were a little less trouble free than your run of the mill Chevs.....

[Chris "drooze" Wertman]

Originally Posted by Rich Biebel

Another piece of advice........ditch the oil accumulator......I really see no reason for one on a stocker unless your playing with very low oil in the pan or it is doing giant wheelstands..

The very presence of it was at Mopars guidance for "oiling issue" or reduction of it, its going byebye on the next motor, maybe itll go back maybe not....

Were following Duells lead on this hes not running one either I know a few of the hemis ARE after the Tech bulletin and some prior failures (to ours)

I agree, I dont like it and I dont trust this solenoid and its operation. So its going byebye.....

At this point "were on our own" in regards to motors so, well, I dont have to explain why Im not running something they said to run.....easy..

Thanks

I do have a question in a SBC you are running how much rod offset do you have on a wrist pin from the perpindicular center ? This is a left field question but one for "refrence"

Cheers

Chris

[Rich Biebel]

There is no offset on a small or big block chevy rod. Pin hole and crank pin holes are on center......

I can't think of any common engines that use offset rods. Pistons pushing on rods off center from the rod? I am not familiar with any engine that has this design....

[Chris "drooze" Wertman]

Originally Posted by Rich Biebel

There is no offset on a small or big block chevy rod. Pin hole and crank pin holes are on center......

I can't think of any common engines that use offset rods. Pistons pushing on rods off center from the rod? I am not familiar with any engine that has this design....

Its done in small bore engines all the time in their "street" trim, used to be more common it helps quiet forged slugs during expansion a bit and for example on a 2 stroke, well piston slap is a biggie since hanging ports is a great way to start a new small shiny part collection.

It was my understanding (apparently incorrect) that some of the small chevs did this commonly.

Not rather the rod is offset but from the journal to the pin in straight fashion is sometimes by say .030-070 pistons are also different for the pin offset.

I know in the LS stuff there is now a "offset rod" that puts it on center since the Hemi is using a LS 6.200 .927 rod, I wanted to see what options were available to get the CORRECT offset (as in 0) because the use of the Scat rods does just that it does not sit in the center of the pin, and my bearing sideload will be greater, cap stess on bolt greater at High RPM, and it would really flipping explain what I am seeing now on several motors in regards to the bearings along the radius side where the cranks mic perfect.....but it looks on the bearing like the journals arent square...

Like I said I thought the SBC was this way my bad.

[Rich Biebel]

Stock pistons often have an offset but the rods themselves are not offset. The offset is about .060" on a small block......Maybe that is what you meant and I misunderstood the question......In Stock we often used TRW pistons and turned them around so the offset went the other way...... The TRW forged pistons that were used to build a 350 Stocker engine has the offset in the pin hole......L-2256.....forged flatop 4 valve relief......Hang them on the rods so the arrow that is normally facing forward is toward the rear......

I had a G-H/SA '69 Nova back in the '90's and built a "cheap" shortblock using those pistons.........Dykes rings with spacers......

[Chris "drooze" Wertman]

[QUOTE=Rich Biebel;176267]Maybe that is what you meant and I misunderstood the question......QUOTE]

It was, the answer was worded wrong, I have my kids over and I miswrote what I meant being shot at with a large plastic man from a cannon as well as dressin barbie dolls in between. Its like herding cats right now.


That was it.....I miswrote what I mean ,I used the phrase perpindicular to the center , and that was not even close to what I meant...

Wonder if there is a Leauge for herding cats ? Id be ace...

[Alan Roehrich]

Buy your self a good bolt stretch gauge and use it religiously, forget using a torque wrench on rod bolts. And use it when you check the big end of the round for straightness and roundness. You are doing that, aren't you? Use the bolt stretch gauge when you check the ID of the bearing in the rod, too.

The old rule of thumb "0.001" of clearance for every 1" of journal diameter" will do you just fine until you figure out the real needs of the engine. It holds true in most engines, especially when the rod journals are between 2.0" and 2.3", and when the main journals are between 2.3" and 2.75". This is if you are using any good race oil between 5W/20 and 15W/40. If you run 20W/50 (why?) go a little looser, if you run 0W/10, tighten it up some.

A properly plumbed accumulator will not cause a problem, an improperly plumbed accumulator will blow your engine.

I like coated bearings, I have mine done at HM Elliott. We could do our own, but considering the time and operation involved, we don't. Honestly, they sell me the bearings already coated cheaper than I can buy them and coat them myself, if I consider time, materials, and equipment. They now do the coating for Mahle Clevite. They coat my skirts, if I don't have it done when I buy the pistons.

Avoid the rest of the trick stuff. If it won't live at all without cryo and DLC, it won't live anyway. Yes, you can do that stuff later and maybe find some gains. But right now, you need something that runs and lives. Follow the number 1 rule of engineering, because it applies to racing just as well: KISS. Keep It Simple, Stupid. A wise old racer named Tom Polk once told me "Tricks are for kids, you pour 'em in a bowl, pour milk on 'em, and eat 'em". Some of the best advice I've ever gotten in well over 30 years of this stuff.

You need good solid machine work, and good solid basic parts. All of the other silly stuff will do nothing but cause you problems, at least until you have 3-4 good solid engines you've done that run well and last. After that, then you go fooling with the rest of it.

By the way, you've already met a real good guy to help you through all of this, Bill Grubbs. Talk to him, listen to him, and pay attention. He knows a lot more than he lets on, and he'll show you the ropes. He's no engine builder, and he'll tell you that. But he knows who IS an engine builder, and where to get good advice and information.