Here is my situation. I just got my block back from the machine shop. Crank grind along with new bearings. Ive had this machine shop do crank work before. The last time the bearing clearances were .0015 using acl standards. Now im using acl .025 and had the crank ground 010 (not sure ill have to check again). Last night I was doing assembly and my plasiguage 0015-003 hadnt even smashed. So I did the math and its coming out between .006-.007 on my main clearances. Is that possible to run? I havent checked rod bearings yet, just because Im not wanting to get to deep if there are some major issues with machining. Anyone know if this is runnable?

 

i have a friend that is running .020 clearance. it is in a gsr and he plugged all the oil jets in the bottom end to compensate for the oil pressure drop. but that is on a race motor only that hes using it on. good luck

 

I am definatly not an all race engine.

 

I would not run the clearances you have on any honda motor.

 

that s kinda what I wasnt wanting to hear, but I knew it was what I would be told. Im going to go out and measure it for the 10th time. Thanks for the help, if anyone has any other suggestions Im open for them.

 

good luck

 

just got back in. The weird thing is, the part number for the main bearings are diff. but they are coming out to be the same thickness. the orig part number was 5m19590/S10-std. The new part number is 5m1959- .25. Im just really confused as to what is going on.

 

haul that bitch back to the machine shop and tell them to fix the **** up that they did. we have some piece of **** shops around in my area that dont understand that its not a chevy motor you dont just slap it together and expect it to run

 

well first off its ERL, second its the second time they have done work to the engine, the first time was flawless. Not to mention its 2 hours away and I had it shipped so I could have it built and installed this weekend, so I could have it in and tuned by next week. Just a crappy situation that ill have to sit on till monday morning. The whole reason I sent it off was because all we have around here is chevy ppl and they havent built and engine this tight in there entire life.

 

did they bother checking any of the clearances before they shipped it?

 

it came with a tag specing all of the rod and main sizes. Honestly it doesnt look like they checked to see if it would work properly. They also did a .5mm overbore which is dead on. Im just going to have to call them tomorrow and see what is up and what they are going to do about it. Wish they were there today, I would have already of called.

 

You are leaving too much out of the story. Why did you have the main journals reground in the first place? Did they really grind .010" (.25mm) off the mains or was it .020"(.5mm) ground off? 5M1959 is the standard bearing and 5M1959.25 is the oversized number for .010" ground off.
Last but not least, you cannot measure bearing thickness with anything but a BALL mic. Regular mics do not work and calipers can be tricky also. You mus only measure the bearing in the very center of the U. If you are measuring near the tang, you will get false readings.
BTW, you cannot run your crank at .020" like someone else said. Probably about .002" max.

 

well for measurement of the actualy clearnce I used green plastiguage (.0015-.003) after seeing that the plastiguage hadnt even been squished I measured the bearing with a standard mic (which could have been off but I measured 10 or so times). The reason the engine was in for a crank grind and over bore was due to me detonating during the last engine tuning. melted the tops of the pistons near the ring lands and had minor scoreing in the bearings, so we opted to just replace it all. The engine was orig machined by them, (sleeved, line bored and honed, creating the orig 10 over) since we had to grind the crank again due to scoring it was another 10, so that is why the new bearings are .25. I will go out and the journals to see if the size they wrote is the actual size that the crank came out to. But does plastiguage lie???


when I say 10 I mean 0.010

 

You can measure 100 times with a normal mic but it won't give you close to the right answer for bearing thickness. One side of the mic has to be shaped like a ball.

 

ok Ill take your word on it, but wouldnt plastiguage tell me if the clearnce was incorrect?

 

also here are my specs

the main housing bore should be 2.3340

the journals are as follows
2.1550
2.1550
2.1549
2.1550
2.1548

That is the specs they gave me, as well as I confirmed with my mic that it "appears" to be the same to me, wouldnt that suggest that the .25mm would fit correctly.

I know that the orig thickness of the std10 was approx 0.0838 which is what they measured and the journals were 2.1650 all the way across the engine. As of right now I dont know the current thickness of the new bearings, due to my lack of tools.

Ill take the bearings to work tommorrow and use one of the ball mics we have there. Do you happen to know what the thickness is supposed to be?
This is only my 4th engine Ive ever built so Im pretty new to it, I have a decent amount of money invested and I really prefer to do thing correctly. Good news earl the valves I bought from you are doing superb.

 

From the numbers you have supplied, I think you need standard bearings. They should give you .002" (approx) clearance. I don't think you have a reground crank

 

Try plastigaging with a set of standards and you are right in saying "plastigage never lies"

 

Are you thinking they just polished, that was the orig plan but then it later changed. If I had a new set of standards Id be fine but I dont. The only thing I have is my old used set, with some marring. would that be ok to use.

 

polish them with some Scotchbrite pads and use them for a test fitting

 

i run .0017 on my main clearances.

 

will do... what should be the max im looking for?

 

max is just like earl said .002

 

i just build mine on the loose side of factory specifications.

 

well still no luck using the std bearings. the plastiguage is still showing over .003.