310HPS2k

Ok long story short, my H22a4 was built N/A with high compression pistons, the whole package. One day it just detonated on the road, and the pistons were fried, and scoured up the inside of the cylinder walls. The rod bearings were paper thin and all fried up.
This caused for a rebuilt, i dropped the compression and build for turbo. and 4k miles later it happened again. Opened up the motor and find the damage to the rod bearings again.

Pro Import says its oil shortage to the 4th rod bearing..... chamber? Says that it could be a bad block, but they couldn't find out what is wrong, 2 machine shop has looked at and cant solve that problem.

Anyone else here has this problem?

Now i have to choose, should I put in another set of bearings, and chances are it MIGHT happen again. or get a new block altogether..... VERY TIGHT on money now after 2 rebuilt in the last 8 months.....

Any input would be appreciated.

PS. Tony if you run into this please give them a better description than I did.


Thanks MIKE

Pullig

i bet you got a crank journal outa spec. Did you have the journals micd to see if its within tolerance?

PrecisionH23a

Sometimes when machine shops do machine work to the block they do not clean the block out afterwards and shavings fall into tiny oil passages.

You always run a risk when re-using a block/crank that has had bearings spun previously in it. When doing so setting bearing clearances is very important. I always try my best not to work with set-ups like this for fear of running into bearing failure in the future.

Where you monitoring your oil pressure by any chance? Did you have the 'new' engine properly tuned during the 4000 miles you put on it? What were you reving the engine to? What bearings were used and what were the clearances?

Either way... I would recommend purchasing a new bare block and crank since you have had so many problems with your current engine.

310HPS2k

Quote from Tony who did my motor

"Let me step in to help Mike out. I am the one that built the second motor for him. When we got the car the first time the motor was grenaded. After we pulled it apart and checked all of the damage you could tell that #4 was starved for oil but it had so many other issues from the first rebuild it was crazy. The sleeves were installed wrong, the balance shaft bearings were beat in with a hammer, 12.5 to 1 pistons installed with no knock sensor and he was told to "just run pump gas". I could go on and on. But anyway i rebuilt the engine and both i and the machine shop noticed the problem with #4 but couldnt find any reason for it. The crank was checked and polished and the oil passages were checked. The block was hot tanked so that there would be no debris in it afterwards. All oil galleys were checked and were good. I even went over to the machine shop after work one night and checked the block with him when he said he couldnt find any problems. I use this machine shop because he mostly builds racing engines and he is meticulous about his work. We disassembled the oil pump and checked it. After assembly the engine started right up and ran great for about 2 1/2 months with no noise or smoke and then Mike said he was downshifting for an on ramp and it started making noise so he shut it off. When i disassembled the bottom end the #4 rod bearing is hammered out again. The pistons, cylinders and main bearings still look good but the rod bearing is shot. I usually do sr20's with a few LS vtec's thrown in for good measure so H22A's are still new to me but as i told Mike i think at this point as many problems as he had had with this motor i would be looking for another block. I hate going behind someone else's work because you never know what was done, I mean like the rod caps were not even marked so how do i even know if they were put back in the right place. Of course i have them marked now but i can only put them back where they came from. Mike just wanted me to post the info so he can get some feedback. Thanks in advance for listening."

PrecisionH23a

So did they measure the clearances on the bearings?

twistedbydezign

this thread is reinforcing the tedious task of plastigauging that i will have to do when reassembling my motor....my journals were all within spec so hopefully the bearings im using based on the #'s on the crank/rods/block will still be good....but we havent heard from the op/builder on whether the motor was micd or micd and plastigauged.....

and not to thread jack but my other thread hasnt gotten any response yet, but when plastigauging and disassembling, whats the best method to get the main caps off so that the journals dont get messed up and no pressure other than the main bolts torqued gets put onto the plastigauge to mess up the results...???

PrecisionH23a

Use a rubber mallet to tap them while lifting up at the same time. Wiggle back and forth and use a tiny flat blade to pry them up very carefully.

twistedbydezign

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">Use a rubber mallet to tap them while lifting up at the same time. Wiggle back and forth and use a tiny flat blade to pry them up very carefully.</TD></TR></TABLE>

thats what ive been doin, seemed like it wasnt the best way though, i figured id be ruining something with as delicate as journals and bearings can be....thanks

proimport

Bearings were all plastigauged and all rods were sized. Crank was checked and polished. Not my first rodeo. Dont really have an answer on this one though. I can say that after 23 years of building engines this is the first one to do this that i cant find any reason for.

PrecisionH23a

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by proimport &raquo;</TD></TR><TR><TD CLASS="quote">Bearings were all plastigauged and all rods were sized. Crank was checked and polished. Not my first rodeo. Dont really have an answer on this one though. I can say that after 23 years of building engines this is the first one to do this that i cant find any reason for.</TD></TR></TABLE>

And what were the clearances?

proimport

Clearances ranged from 0.041- 0.048.

PirateMcFred

Um, what unit of measure do you want to ascribe to those numbers? Cubits? Rods? Furlongs? Attoparsecs? I hope you mean millimeters but one can never assume too much.

Pirate

PrecisionH23a

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by proimport &raquo;</TD></TR><TR><TD CLASS="quote">Clearances ranged from 0.041- 0.048.</TD></TR></TABLE>

On the main/rod bearings? Is that in mm or in?

proimport

Lets go with rod bearings in mm

The Weather Man

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by proimport &raquo;</TD></TR><TR><TD CLASS="quote">Lets go with rod bearings in mm </TD></TR></TABLE>

PrecisionH23a

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by proimport &raquo;</TD></TR><TR><TD CLASS="quote">Lets go with rod bearings in mm </TD></TR></TABLE>

From my plastigauge, you are around .017-.020" which in my opinion is fine.