So the deal is, I tore my motor apart and everything looks good except 2 things.
1) I broke the top timing chain guide in half
2) The lower part of the main bearings are worn down to copper
This all happened within about 2500 miles.
Anyone making a lot of power, please post if you have had similar problems or have any ideas...
Just trying to gather a bit more information before I put this motor back together...
Thanks,
Jeff
--------------------------------
2000 Turbocharged Silver Z24 5spd
Cardomain Site
it sounds like you have an oiling problem. what is your setup? More info needed to give a better response.
99 Turbo Sunfire GT | Ram 2500 | International Rollback | Mr Hanky the Suburban
are you the guy with the stock block and everything that ran like a 12. something????
Thanx Charles
Jeff is running a 2.3 oil pump and I believe he is using clevite bearings....
Hey Jeff, about the upper timing chain guide I am thinking chain is flexing outwardsunder boost putting stress on that sucker.
Maybe it was just a worn out chain that made it happen, but maybe you will have all the problems that Mike Karas had with his chain and I think he did.
Lets hope not.
Lower main bearings being chewed down is simply in my opinion from the pressure, that the pistons and rods are putting on the crank and weak main caps and bolts not being able to hold it up.
You lucky the crank didn't fall out, or even worse, had one of the caps give out and broke the crank.
I would deffinetelly check the crank by balancing it before it goes back in the block since of the problem, and find a way to check the main caps.
Another thing to do to conclude the problem is order a main cap bolt which would cost you like $5 and mike that one opposed to your old one and see how much have the bolts stretched, cause I am almost positive that they have.
A set of Clevites and some min cap ARP studs I am pretty sure would do the trick as for that problem
I am sorry I couldn't give you more input for the chain.
P.S.BTW, get the crank main journals miked as well just to see if they need to be ground due to bearing damage so you can choose proper bearings.
I hope this helped
Good luck buddy, I loved your trap speeds 117 mph! lol
Best time:"""11.946""" @ 114.73 mph @17psi 1.83--60"
11 second daily driver!!!!
Race Related 727-561-9440
Shop of choice for your 11 second J body!
Also, built bottom end and or top end LSJ and L61's available.
13's
----12's
----11's
----10's
Also, one more thing you should look into is of you have a good rep shop around, see if they could weld your #2,3,4 main caps together, so resemble a partial main girdle, but this have to be done with extreme accuracy, because if not the caps with destroy your crank counters, since the back lash between them and the caps will be off, if welded inproperly.
I know the 1st Gen DSM's have #1,2 and #4,5 main caps joined together.
Best time:"""11.946""" @ 114.73 mph @17psi 1.83--60"
11 second daily driver!!!!
Race Related 727-561-9440
Shop of choice for your 11 second J body!
Also, built bottom end and or top end LSJ and L61's available.
13's
----12's
----11's
----10's
Pics of the guide?
Any records on clearances and crank work when 1st assembled?
sig not found
Ok, sorry for the lack of information.
Yes, I did pull a 12.9 on stock motor with a T3 "Super 60" with a 50 trim wheel.
I experimented with timing on night last summer and threw a rod through my block.
I have a built motor that I put in last summer.
Most of the specs are in my reg.
I am using ARP mains and I am using Clevite 77 bearings on everything.
The clearances were checked by a local shop and everything looked good on the main and rod journals.
I do have the 2.3L oil pump conversion.
ALL timing components were bought brand new. New gears, all 3, new guides, new tensioner, new tensioner shoe, new chain, everything new.
I have talked to Mike about his setup and I might be having the same issue he was.
The crank was regound to M - 10 and R - 10.
I can get a picture of the guide for you as well.
Also, on the timing cover (both sides) you can see where the chain was slapping against it on the right side near the right guide. Also, you can see where it was slapping against the housing where the tensioner shoe sits.
Other than these 2 problems everything looks new.
Any more suggestions, feel free to post, or if there is more you need to know just ask.
Just for more information, I did have 2 turbo's go bad on this motor and there might have been some metal shavings that got into the motor possibly? I did not find much in the oil pan besides the normal specks from engine break-in. Is it possible that some metal could have gotten into the bearings, but I would see more damage on the top as well as the bottom of the main caps and possible on the rod journals? But the odd thing is is that there is no damage what so ever on the rod journals, and the crank looks mint and the top portion of the main bearings look great as well...
Thanks,
Jeff
--------------------------------
2000 Turbocharged Silver Z24 5spd
Cardomain Site
Well, the bearings will be under a higher stress concentration with an underground crank. And with that much power, you should probably look into a stock crank. You could also try retarding the timing a tad to put a lesser load on them. Did you have any problems with detonation/pre-ignition during the tuning? This would probably lead to increased wear on the top rod bearings as well though.
You could try having the timing chain/guides and bearings cryo-treated. It's not scientifically proven, and rumors could just be rumors...but it could also help out a lot.
It doesn't sound like you were having oiling/contamination problems since it was only the lower half of the mains, that is pure stress. Oiling would foremost be indicated by the rod bearings. Since the bearings weren't worn all the way through and the wear sounds uniform (I would hope you would mention if the wear wasn't concentrated in the bearing center), there shouldn't be any problems with your main caps and bolts, so no real need to measure them, much less weld them together.
fortune cookie say:
better a delay than a disaster.
I really hate to diagnose anything without any back-up info, but I'll give it a try.
1st bearing clearances... what were they to begin with. Wider clearances will need more oil. Wider than wide will lose pressure at the bearing, not on the gauge.
Bearings are sold for J's in Metric. Cranks are cut Standard.
WIth proper clearances in the .001 to .003", a crank cut .010" under for a clearance of .003" is paired with a bearing that should be cut for a .010" bearing when it is actually a .00984" (.25mm) bearing.
It a small difference, but that not all there is. I have no idea how reputable the shop is. Most shops don't take 4cyl guys too seriously. The work you get is just enough to "get it down the road"
Factor that in, and its easy to see clearances that are 1-2thou. too large. Without checking this during the build, there's no way to know.
Damage to bearing like you described is common for detonation. The crank is loaded on its non-oiled side (bottom). The rods are oiled on the loaded side (oil hole faces up at TDC). Detonation pounds out the oil on the loaded side, the rod gets more pumped in while the crank can't do the same (has to turn to get more oil). Crank bearings get destroyed.
What do the pistons look like? You had to destroy a piston to put a rod out the side and not damage (weld) a rod bearing. I doubt the rod snapped 1st (unless it was just defective).
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