Eagle Rods + Stock Pistons?

[Rennat]

i wanna redo my engine... im not happy at all with it, and im trying to figure it all out BEFORE i do it this time.... :3d_frown:
i would like to reuse my eagle rods as they only have 300miles on them.

I know it can be done, but how? are the eagle rods any different as far as the wrist pin compared to a stock rod?

and if it matters... these are the pistons i plan on buying. i researched and a few people on here run them, and there fine.
http://cgi.ebay.com/ebaymotors/ws/e...RK%3AMEWAX:IT&viewitem=&item=160280384261

 

[Poodles]

Why? The stock rods aren't the weak part, the pistons are...

 

[Rennat]

i want cast pistons for my DD... i'll be at stock HP for a while... so the cast will be fine. and i want to keep my eagles because the stock rods are prone to failure unless they have ARP rod bolts...

and after seeing people hit 400hp... and then 700hp with stock internals... im much more confident in cast pistons. its all about the tune...

 

[IJ.]

Thought you had Probes already?

 

[7MGTEsup]

Thought you had Probes already?

what he said

 

[Rennat]

I do. and i want to change them.... im having oil burning somewhere... and its only getting worse. so yeah...

soo.... can i just put the eagles onto the stock pistons? or do they not work with each other?

 

[benchwarmer]

Changing pistons seems unnecessary to me. If the problem is burning oil then you probably have a bad seal or ring somewhere in the engine. I don't see how your pistons could be causing the problem after only 300 miles.

 

[Zumtizzle]

Why?

Get stock rods or a good short block?

Hell maybe a cressida short block?

 

[CTsupra]

Omg, someone just answer his question.... Let him do what he wants.

 

[QWIKSTRIKE]

Get new rings and maybe a new block and get the blocked bored and honed to the pistons, and then break the rings in properly. DON'T go back to stock pistons because the rings or the bore and hone is your problem. DON'T DARE go back to stock over a ring issue.

 

[Supracentral]

Omg, someone just answer his question.... Let him do what he wants.

Negative.

I'm not going to advise someone to do something I think is stupid.

If I'm going to advise someone, it's going to be the right thing to do.

Finding out what the poor oil control problem is, and fixing it is the right thing to do. Forged pistons aren't the problem here. Poor oil control is.

Puttting stock pistons on forged rods is like putting an 80mm turbo on with a stock fuel system. It makes no sense.

 

[bmoss85]

you are wasting your time to go back to stock pistons. you have a problem elsewhere if you're burning oil. did you check all of you clearances when you put your engine together. how did you break in the engine? was the head rebuilt?

 

[arz]

Did you do a leakdown test? Maybe you only have a few rings that need replacing.

I know I had an issue with leaning out my JE pistons, I did a leakdown and only a few cylinders are bad. Although I am not happy with the oil consumption its not worth me taking the whole motor apart at the moment. When I do, if there is enough material there, I will just fix the cylinders in question.

I have still never seen a fool proof way to make sure its broken in properly. I inadvertently broke mine in the very mellow method, it would require a whole nother post to describe what I did.

Im confident mine was broken in properly, I have the actual moment I leaned it out and it started to smoke on film. Its pretty depressing but the event is a blast to watch. I was chasing down a C6 ZO6 on the scenic drive in Vegas. I still need to convert that video to MPEG.

Pull it all apart, make sure none of the pistons or rings are broken, none of the piston/cylinder walls scored, and find out EXACTLY where the problem is.

If your not confident of the Valve stem seals, it wouldnt be a bad idea to do these in the vehicle using an air compressor, or the rope method. If thats the issue then pulling it apart would be a big waste of time.

Your suspisions are accurate if you know the Turbo is good and all that.

I still vote on doing a leakdown either way.

 

[WhtMa71]

^I vote for what he said! It could be something as simple as an improperly installed valve seal or two. How much oil is it using?

 

[IJ.]

Still would like to know what the issue is with the probes, I suspect incorrect clearence when it was bored could be the problem.

If so would make much more sense to get another block and a machine shop that can read a mic.

 

[Doward]

Agree with IJ here. Poor oil control is your problem - find out where.

What piston-wall clearance was used?

What were the rings gapped to?

Are you certain you have no oil leaks?

 

[Rennat]

everything was done according to the probe piston thread doward.
.0032 piston to bore clearance (as per the thread)
.016 top ring
.018 mid ring
oil rings didnt need any gapping (they were already at .013)
i told the machinist all about the honeing i wanted him to do, and the 30 degree crosshatch... he acted like it was nothing and wouldnt be a problem.

i suspect i was a victim of a 'get it done and get it out job'... because they lagged on me for a week, because they had a guy get sick, and then another guy just up and quit... so one day turned into two... and two days turned into 3... well i got all of my stuff back 5 days later than they told me.
and did i mention that EVERY SINGLE valve is out of spec? my cams make horrid amounts of noise and its beyond annoying...


i have one drop a night, oil that is, (after i drive) from the rear of the engine... which i suspect is the rear main seal.

car idled for a total amount of... 10mins before i went out and drove it in 3rd gear and did 7 consecutive high vacuum pulls down the long road next to where i live.

HKS 3mm MHG torqued to 80ft lbs... and then after 5-8 heat cycles i torqued it to 90ft lbs.

and my issue isnt with the actual probes, is the rings that im concerned about... but im going to see what aaron says about getting me some rings and how much they are going to cost. because i would love to stick with this motor if i can, i just wanted to go stock pistons for the fact i know those will seat properly...

Heres a list of the machine work i got done....
degrease block
boring of 6cyl w/ TQ Plate
resurface block
line hone mains
surface flywheel
basic valve job
add shim
resurface head
R&R guide alum
2 new valve guides
grind crank
balance
exp. plugs

i did everything 'right' as far as machining goes... told them to torque the timing tensioner to 36ft lbs? (i had them write it down when i dropped it all off). Told them to surface below 30RA... and heres a picture of my spark plugs for all of you to enjoy. cylinder 3 is the worst out of the bunch... i posted a close up so you can all enjoy. the gap is still correct... but its got build up on it.

 

[IJ.]

Did you measure anything when you got the parts back from the machine shop?

#3 looks to be a stem seal issue more than rings.

 

[Supracentral]

New rings and a different machinist. I wish you were local, I'd have Bryan Maloof look at it for you. Best machinist I've EVER had. And Jack Merkel used to build my motors, if that tells you anything.

 

[Rennat]

i'll give you a few different scenarios that have happend to me...

(last tuesday) for smog, i show up, and i leave the car running, it idles for about 30mines (temp never changes or anything like that, it just runs perfect. he pulls it onto the rollers and starts to center the car and its shooting greyish/blueish smoke... and then stops. he then starts to perform the test and for 75% of the low speed test its smoking pretty bad. but it stops, goes to high speed and its GONE. NO SMOKE. and i pass smog by one point on the HC... high speed HC was fine. and my NOx was below 30 on low and high speed...

(BEFORE i had my turbo rebuilt) i had my friend drive behind me, said i smoked the most when i would get on it, boost hard, and i didnt smoke at all under vacuum... or while just cruising... but while im cruising, its like i have a 'miss' and it makes the car kinda jerk... its not horrible, but you feel it. but its only while cruising... NOT under boost. and it does it a little during low throttle accleeration.

so what are your guys thoughts? pull my head and take it to a new machinist and do a leak down test before that so i can see if its my rings?