wastegate pivot loose

[rlvelin]

I just completed my version of a homemade boost control but can only achieve about 10psi of boost no matter how tight the spring is adjusted. I did notice that the wastegate pivot has considerable freeplay in it, it can rock fore and aft about 1/8th inch.

Can this cause a poor enough seal around the wastegate that the pressure is bled through instead of spinning the turbine resulting in lower than optimal peak boost? Does anyone know of a fix for this, maybe the pivot can be replaced and/or bushings installed in the turbo housing? Can the wastegate be removed from the turbo in order to facilitate repairs?

Thanks for any help.

[Marty Lau]

A bushing can be installed by a machine shop.

[gmctd]

You should have it fixed, but the 'gate flapper is on a pivot, such that it will seal even with wear.

Danger is exhaust leak

[MTTwister]

Speaking of wastegate pivots - "we" were tossing around the idea of using an Aircraft - high temp grease to lube the pivot. DO they make grease that will stand up to those high exhaust temps? Where's Greg L?? or you other aircraft engine guru's?

Rlvelin - hey Great weather we're having, huh? Thinking about pulling and gutting the CAT - but not sure what I'd be letting myself in for.

[DennisG01]

Twister-

I just gutted my cat - ended up not using it, though. Pretty easy to do. I used an old 18" socket extension and a hammer to knock out the middle of the "stuff". Then I was able to hammer/scrape along the sides and it started to come out in big chunks. The "stuff" is very soft - a hole saw with an extension would work great.

[MTTwister]

Totally O/T now - I've got the front 1/2 of the CAT loose, but it's not coming out of the rear pipe. 'Fraid I may have to saw it, but I want to be sure I can get some 3" pipe( 10" or so) to splice it all back together, first. Then, all I currently have is a Hack Saw - this looks like a nasty job.( I know, go buy a SawsAll...)

hmmm no word on the High Temp Grease? gratutious back to topic.. smile.gif

[rlvelin]

MTTwister

Have you got your cat gutted? If not I have a heat wrench (Oxy Acetylene torch) and a come-along. I have successfully dislodged stuck cats with this setup in the past.

It would be interesting to know if there is a high temp grease out there that would be applicable. I wonder if graphite would stand up to the temps? I'll have to look up the critical temps or melting temp for carbon and maybe try some when I get my wastegate fixed.

[MTTwister]

ryan - O/T - Thanks for the offer. ( Hmm, would a propane torch get it hot enough to loosen up?) Current plan -I have a 10" length of 3" pipe, and am planning on cutting the pipe behind the cat, and splicing it back together again. Got the pipe from Dick's Exhaust - and they have a Way Cool Aero Turbine muffler that I might look into, once I get this done.