Hey guys, I have my block back from the machinist and I'm getting ready to start putting this beast together. I picked up a good barrel micrometer (with the zero-ing anvils) and I have a bore gauge so I want to double check the work.
I have the Wiseco forged pistons on the stock (reconditioned) rods and I have Clevite P series main bearings coming. In a moment of weakness I bought Sealed Power rod bearings. Should I return them? I couldn't find a set of Clevite.
Anyway, the machinist said he left the piston to wall clearances loose so I could stomp on it here and there so I'm wondering what "loose" really means. I found the specs in the CSM but assume they are meaningless at this point.
What kind of clearance do I want for a street motor that gets stomped on once in a while (maybe more than I should )
And for the rods and cam is the .001" per inch of journal the way to go?
Many thanks!

 

The Sealed Power rod bearings will be fine. Find what Wiesco recommends for those pistons. Hopefully they won't rattle when the motor is cold. Good luck.

 

Yeah, I've been looking but can't seem to find it on the net. I'll call Wiseco tomorrow. I've also been reading about the cold rattle, I didn't know about that. How bad is that for the pistons and bores?

 

Okay, I found the paperwork. It was hiding under the ring box in the piston box. Suggested clearance is .0035". But, like I said, the builder said he was leaving them loose so I can romp on it so I wouldn't be surprised if the clearances are a little more. Is that a bad thing?
I'm going out this morning to check at least a few of them. I got my micrometer zero'd out. That took some time for a newbie like me, lol.

 

BTR says it's difficult to determine the true diameter of the piston because different people measure it at different spots along the piston. Maybe Wiseco can help on where to measure the piston and therefore determine the clearance.

 

ALL piston manufacturers will tell you where to take the measurements.
And that's a 4032 piston, meaning it's designed to run with tighter clearances. If you have more than .004-.0045 then your idiot of a machinist owes you another block bored to the right size. He's a moron.

 

Why call the machinist an idiot and a moron when you have no idea how much clearance he left?

 

Very simply because the op wanting to "stomp on it" does NOT warrant extra clearance, period. That piston will handle waaaay more power at the recommended clearance than his build will ever make.
The ONLY things that warrant that are nitrous and possibly running different fuels, i.e. E85 or maybe Propane.

 

Wiseco does indeed specify where to measure the piston; 1.3" from the bottom of the oil ring groove. I measured a few today and the clearances so far look to be right at .004". I probably won't be able to get to the others until next weekend.

 

That's acceptable, but the reason he did it isn't. I wouldn't use him again.
Jmo

 

I think TRW/Sealed Power and Clevite are owned by the same company. Back 20+ years ago I use to have the machine shop give me 0.0045 piston clearance, never any problems. The material is better now days and some recommend 0.002. Back in the "old days" 45/50 years ago we used to get the factory pistons knurled to take up the slop and re-ring and re-bearing to "freshen" an engine. Money was tight but the engines were loose.No such thing as credit cards for young people. I was into Chevys and they were pretty durable. Around 8 thousandths they would "rattle" a little when cold.

 

Yah, your an old dude, when is the last time you heard of anyone knurling pistons?

 

Thanks for compliment but 55 doesn't feel very young, lol. And the wife won't let me use the credit card for Olds purchases. She's a very smart lady

Now, how about the crank and cam clearances? .001" per inch of journal? Still waiting on the clevite main bearings. Summit said three weeks, then another four weeks. I cancelled and went with Rocket Racing. Should be here this week.

 

Check out page 28 of BTR's Oldsmobile Performance V-8's. Depending on the bearings and coatings he gives the actual crankshaft journal diameters.

 

Again you should've checked with me first. I have sets of Federal Mogul main bearings (which I recommend) sitting on my shelf. I have a few sets of Clevite Rod bearings as well.

 

Mark:

Do the Federal Mogul match the Clevite diameters once torqued? In other words do you grind the crank to the same specs BTR specifies for Clevite? I'm not trying to compare
your way of doing things with this but was hoping you might know. Not trying to steal your thread Mac, thought you might be interested in the answer as it may apply to your build.

Randy

 

Well crud
I'll let you know if something happens and they go on back-order.

No worries, Randy. Info is good for us all.

 

No, the FM will have about .0006-.0008 more clearance, all else being equal.
But they're also only a 5/8 groove instead of a full groove. That'll handle the load better.

 

Hey Mark, out of curiosity, are you using a vacuum switch with your 200-4R? I didn't care for it so I'm just using a manual toggle. And I still need to install a brake switch for safety.

 

I'm a fan of the 0.001" per inch of journal plus 0.0005" for performance use. That puts your mains at 0.0035".

 

Thanks Luke!

 

No, my ECM controls it. Tried all the other stuff, hated it.

 

Ahh, post rocker-switch technology. Nice.

 

I am still hoping to get mine right, the TCI out of box locked/unlocked like crazy. I adjusted it too much, sometimes didn't lock when I wanted. I don't care for the toggle switch either. I have the same issues with fan controllers, they die at the worst times. Maybe an efi set up from Mark is the answer.

 

Yeah 307, mine's outta' whack too. When I first installed everything, the lockup solenoid was sticking and I didn't know it. I thought it was the switch but it wasn't.
I kind of like the toggle. It makes me feel like I have a manual trans, lol. Although EFI would be way cool, I wouldn't know what to do if I wasn't adjusting my Quadrajet every weekend.

 

I installed the Clevite P series standard bearings and used my micrometer and bore gauge to measure the clearances. I'm coming up with a clearance of .002". That seems tight to me so I called Mahle and a tech guy said they should be from .0008" - .0038" and that .002" is right where I want to be unless I'm running a blower or NOS.
I don't plan on taking it to the track but I do want to have the freedom to take on a tuner (and probably lose, lol).
Opinions?

 

Keep in mind that I don't quite have the feel for the mic on a round surface yet (journals), which is why I'm taking several readings. And I'm measuring the bearings with 120 ft. lbs on the caps (with ARP studs and lube) and at 90* to the parting line.

 

I'm not an expert whatsoever but it is my understanding of BTR's book you would want a minimum of .0035. Even more for higher RPM's. Are you using oversized bearings?
You could get your crank polished, not sure how much clearance you would gain. Hopefully the experts will give some suggestions.

 

You never polish to attain the clearance.
The "tech" at Mahle Clevite was just reciting what's in the book, no more. They seldom have any practical experience.
.002 is tight to me. Are the main saddles round without the bearings in them?
ARP studs take 110, not 120.

 

I ordered standard size, but there isn't any way to know until I pull the bearings, it's not marked on the box. I'm assuming they are but I'll check, of course.

@Mark; I did not check the saddles before installing; I will do that. I could have sworn the ARP paper said 120. I'll check that too but if it said 110, then I torqued to 110 (I wrote the update from school). Maybe it was the CSM that said 120?

So, I guess my question is now, do they make an undersized bearing, thinner than standard?

 

The CSM states the main bearing clearance should be no more than .0035" but it does not give a minimum clearance that I can find. I realize that the CSM may not be the go-to for this clearance these days but I was curious.

 

Yes, as previously stated.
ARP sheet should say 110, not 120. CSM is 120 with stock bolts.

 

So assuming everything is copacetic with the block, the FM's would get me to .0026-.0028". Should be good with that, yeah? How much for a set of FMoguls? And also important: can I resell the Clevites? They have some slight marking from the bore gauge, which I assume, is unavoidable.

Does anyone make a full.001" undersized bearing? Would that be more accurately stated as oversized since a crank would be "undersized" if ground.

 

FM's are about $130.00. Clevite still makes an HX main bearing I believe. That's supposed to give you an extra .001 but is more concentric than their P bearing.
But if you didn't align hone the main saddles after installing the studs it's all pot luck anyway. That's why I asked if you measured the saddles without the bearings in them.

 

Yeah Mark, I saw the HX bearings and they claim they can be used in a street engine but seems on the sketchy side to me.

The caps and saddles were align honed with the ARP studs, at least I assume that's true since he had the studs before the hone.
I only had time tonight to measure a couple. If my micrometer and bore gauge shenanigans are correct, the front two bores, torqued to 110 ftlbs and without bearings, look to be at 3.1845". I zeroed the dial with the gauge 90* to the parting line and checked near the parting line and there looked to be .0001" difference. But dang if I didn't forget to see if it was larger or smaller.

 

Tunnel sizes should be 3.188-3.189. Are there hone marks in the saddles?

 

Gone marks? Gouge marks? No, no gouge marks.
I think the lesson here is that I'm not very good with these tools or either my mic or bore gauge is off, or both. I do have the zeroing anvils for the mic but the bore gauge is kind of cheap.
Tell ya what, I have another, better, dial gauge I can try with my bore gauge but at this point I think I need a pro. Maybe I'll file my piston rings and take everything back to the machinist for assembly. But it won't be near as fun!

 

Would plastigauge do me any good? I have some laying around.

 

Nope, normally not very reliable. Hone marks? Do the caps look like they've been cut on the mating surfaces?

 

Okay, so I'm resisting trifocals. I only have bifocals.

Hone marks inside the tunnel, yes. On the mating surfaces, no. That was a good question and something I wouldn't have thought of. But the machinist would have put it on my invoice and I looked at that very carefully.

Again, most likely cause is user error. I'm not going to make a move on another set of bearings until I know. I'll keep at it. Repeatable measurements will be my mantra for a while.