sanman000719

see thats productive to me thanx for the answer

nonvtecallmotor

what does the crank an rod look like on that journal (color)?

ashtons300zx

Im using eagle rods with arp2000 bolts and never had an issue with them at 550whp and now going to 700whp in my SR20

If your stretching them your doing it wrong. I checked/measured the bolts when I refreshed the rings and bearings and they were fine. I think you may be overtorquing them or have a faulty wrench that may be overtorquing them.

Plus if you overtorque them enough like I have seen one guy do that actually stretched an arp2000 bolt to where it looked like an hour glass, that is not good for the rod. It will out-of-round the rod and then the rod is junk. Ive seen that happen on more than one occasion as well.

sanman000719

its silver little scarred up from the sount bearing after the bolt let go but other than that its good

i did put over 40 runs on this motor at the track this summer

hello1320

Try doing it your self........if u have the right tools and can understand math......its very easy...do it.you might suprise yourself

sanman000719

some like to do it some just like to drive lol

ashtons300zx

A properly built motor should last more than 40 passes. I had 1 year, 11k miles, 50+ runs, 20+ load dyno pulls, and probably over 300 street pulls pounding the rev limiter every day I drove the car, which was every day, haha.

When i took the motor apart during upgrades to refresh and do headwork the rod bearings and crank were in absolutely perfect condition as well as the pistons, cylinder walls and rod bolts. This was with over 30psi of boost on occasions.

Again like others have said, your either overtorquing them due to a torque wrench problem or a misguidance on the torque spec or something with your crank and bearing sizing is wrong causing the rod bolts to break. Id just make sure everything else is in line. The arp2000 bolts are very very strong.

sanman000719

ok i didnt build the engine a reputable shop did lol

the one thing i am weary of is the crank it was polished to 20under and then they did bearings to match up with it. I was told this wasnt recommended,but went with it so your the first to bring that up as an issue. i was woundering about that. the other journals are perfect (spotless)

doesnt matter its scrapped now took to much of the block out to even think about resleeving. im going to see how long a stock block will last me lol

thanx for all the replies cheers, and happy new years

ashtons300zx

Thats why I do all my own work. I dont like not knowing exactly whats going on. Ive built numerous motors and I like to stick with a good condition used crank rather than a cut or polished crank unless its done by a big name company such as stroker cranks and so on but even then they usually cut the journals to stock specs so a standard bearing can be used.

To me it seems it would be hard to polish a crank down 20 thousands. Polishing is used to just smooth out the surface from minor imperfections scuffing which for the most part cant even be felt by hand. I used a stock crank that was polished up again just to remove every imperfection off the journal. Used a standard size bearing and all was perfect and again never had a problem.

And for the most part most bearings come in .025 and .050 oversize, not in .020. So im thinking something got screwed up causing bearing to spin and knock hard enough to break the rod bolt. It doesnt take but one rev through to high rpms after a bearing spins to turn into a catastrophic failure.

hello1320

you do your own motors ????? 20 over bearings are very common......

hello1320

Cut journal or not if the crush and the oil clearence are right....it will work fine.

ashtons300zx

yes, I build my own motors. And im sure different brands offer different overs as well. Ive seen 10 over 20 over 30 over and so on. You can get almost any size. Im saying the most common are 25 over. Such as what is offered by ACL and even my factory nissan bearings which come in grades and also available in 25 over.

Just stated the most common sizes. lol. Not saying they are not available.

I personally just dont like using cut cranks. you can find good condition cranks that you can just polish up the journals on and not have to worry about cutting for practically nothing. I normally go that route on any motor I build that has a badly scored crank. If the crank in it is free of scaring then Ill have it polished up to remove any imperfections and check it for out-of-round

ashtons300zx

Oh there is soo much more than that involved in building a motor. lol. You can have an oil clearance crush out fine on the plastigauge but have problems with either the journal or the rod be out-of-round and you will have major bearing problems. Rod problems come from motors that have had serious rod knock or the bolts or nuts over torqued. Your top and bottom clearance might be just fine but the side clearance where the two halves of the rods meet will be way too tight and cause the bearing to fail.

This is why if there is any doubt of over torque or rod knock that you check the crank and rods for out-of-round and as cheap as you can get a set of eagle rods for you might as well just replace the rods and replace the crank.

hello1320

Did u say plastigauge......really !!!!

hello1320

Bearing crush has nothing to do with oil clearence

ashtons300zx

lol, I said when using plastigauge it could check out fine if thats the way you go about it. i personally just mic everything. No questions asked every time.

hello1320

No u didn't.

ashtons300zx

Sorry, I know what bearing crush is. And just because the bearing crush is proper doesnt mean you wont have problems if there is problems with the rod or journal being out-of-round.

hello1320

No ****

ashtons300zx

lol, no sense in arguing. All i know is that ive built countless motors and have yet to see one have bearing failures. haha.

Ive also seen what happens when over torquing a rod cap. I had a torque wrench crap out on me and overtorqued a stock sr20 rod. I took them back out and checked the rods and sure enough, it ruined the rod. it was far enough out of round that it would have caused bearing problems within notime. Didnt end up using them and switched them out.

SPOOLINmatt

lol. hello1320 getting all worked up on some plastigauge!

alpha

I'm not an Eagle rod or ARP rod bolt fan. But. Like others have said. I've personally made 1000whp and gone 202 in the standing mile with ARP2000 rod bolts. Something else is causing your issue.

hello1320

that fired me up so bad bro. No BS I shot gunned a four loko after that. New years **** it!!

The sweed

HP does not cause rod bolts to fail. The force from HP comes from the piston and pushes the rod against the crank. RPM combined with low rod/stroke ratio is what puts load on the rodbolts.

L19 bolts are the next step as far as I know of from arp 2000. 625 series is another step from the L19. There might be more options I donīt know of though.

hello1320

Lol...I love coming on here and seeing what I wrote after a night of drinking....