Orange hot turbo on my rb25! I cannot figure out why...

[ANVIL]

same exact sh.it happend to my cas, running no upper timing cover without spacers. dowel broke and the cas shaft seized. picked up a new one on ebay for $100 iirc. took me 3 trys to get it back on the right spot without that dowel.

[Cltchkikr7]

So that dowel is no **** off the camshaft huh? You think that jacked up my timing tho?

[ANVIL]

yes its off the camshaft, and yes, it more than likely jacked up your timing. are you running no upper timing cover?

[Darius]

yes its off the camshaft, and yes, it more than likely jacked up your timing.

+1

This was a long time ago but I thought I remembered someone saying they were able to run without the half-moon piece. They lined the CAS up and pushed it on. It is driven by the teeth so it shouldn't be slipping, but I could be wrong. It hasn't happened to me so I don't have first hand experience here. The tricky part is getting the CAS set on the right teeth.

[Cltchkikr7]

ok turns out the splines on the end of the camshaft were worn just enough to jump splines while running, need a new exhaust shaft, headin up to l.a. tomorrow to pick one up, thx for the input guys

[l0nestar]

Note, there IS a difference between the S1 and S2 exhaust camshafts, specifically referring to the CAS / Keyway / Dowell. The S1 uses a half-circle, and the S2 uses something different. Just wanted to verify with you before you purchased the wrong cams!

I think shocker found this out first-hand (S2 cams on an S1 engine?)

[Cltchkikr7]

thx for the info man, im picking them up tomorrow hopefully and ill call the guy now to make sure

[eh?]

Note, there IS a difference between the S1 and S2 exhaust camshafts, specifically referring to the CAS / Keyway / Dowell. The S1 uses a half-circle, and the S2 uses something different. Just wanted to verify with you before you purchased the wrong cams!

I think shocker found this out first-hand (S2 cams on an S1 engine?)

late late s2's are different. Early s2's are the same as s1's.

[l0nestar]

late late s2's are different. Early s2's are the same as s1's.

I stand corrected. Thank you for this small but important note!

[eh?]

p/n 13020-75T10 93/08-95/01RB25DE 93/08-96/01RB25DET95/01-96/01RB25DE96/01-97/09RB25DE96/01-97/09RB25DET

p/n13020-75T11 97/09 RB25DE 97/09 RB25DET

Just a bit of clarification, 09/1997+ R33 RB25 exhaust cams are different from the rest.

[Cltchkikr7]

so are they different in lift and duration or just in the splines and dowel?

[Bwana]

I'm glad you found a cam. I did some checking around but came up empty handed. If you need help installing it I'll be back out there in March.

[Cltchkikr7]

yeah i just hope its the right one lol. i didnt know there were that many for one motor, but yeah if i dont get it in by then ill definately call you, thanks again for coming out and helping me man.

[zerodameaon]

my turbo starts glowing orange when im on it hard for a while. but its never enough to take a picture of it. but now i really want to find the cause of it now that i know its not just something that happines with these turbos.

[gmac708]

but now i really want to find the cause of it now that i know its not just something that happines with these turbos.

I am a mechanic on aircraft. Some of these aircraft have turbo'd engines. Not necessarily a lot of boost above normal atmospheric pressure, but able to hold that boost @ altitude. Most of these turbos are visible through louvers on the side and top of the cowlings. At night, It is normal for these to glow red hot. I would think this is normal. Most engines are running a EGT gage that shows peak EGT and the crews usually adjust a little richer, or more fuel, of peak EGT. Even when playing around with the mixture in flight, the turbo still glows red.

Some of the operators actually run the engine "past, or lean of peak". Think about it. They pull the mixture back and the EGT actually comes back down to the same temps as it was on the other side of peak EGT.

Anyways... I think it is normal for the turbo to glow red hot, Just make sure you cool it down @ idle before shutdown.