IHADAV8.com - Turbo Buick Tech, and Nonsense

Tech Area => General Buick Tech => Topic started by: Scoobum on September 16 2018, 01:44:31 PM

Title: Puck Sealing
Post by: Scoobum on September 16 2018, 01:44:31 PM
While the engine was out this year I swapped in a new exhaust housing...cuz the other one was pitted to hell from the race gas on the flange affecting puck sealing. I smeared orange silicone on the puck this week and mocked it up to port the wastegate hole. What I found is the puck was sealing no more than a 16th of an inch around the 4 to 5 o'clock mark. I'll assume Precision drilled the hole a little off from my old exhaust housing. I took the DP to a local machine shop this week and had them drill the DP flange holes slightly larger. I was able to move the DP towards the right bottom corner more. Checked it again for seal...and I had a full 1/8th inch sealing at the 4 to 5 o'clock mark. If you ever swap exhaust housings with the same manufacturer check it. Don't assume the hole is drilled in the exact location as the previous one.


A quick thanks to Dan Keller for supplying the new housing to me free of charge.
Title: Re: Puck Sealing
Post by: Steve Wood on September 16 2018, 04:36:27 PM
I have not seen many that were out quite that far but they are usually not centered.  I think they just ream out the existing hole and stay on center...would not take much to be off for sure.
Title: Re: Puck Sealing
Post by: earlbrown on September 16 2018, 06:41:46 PM
My GT3255 with a stock hole was waaaaaaaay off from my THDP (a real one).

I was so bad I pulled the housing and put it on a mill.   If I'd just enlarged it, it would have ruined the housing.
Title: Re: Puck Sealing
Post by: good2win22 on September 16 2018, 09:54:49 PM
I have yet to see one that is centered even somewhat closely.
Title: Re: Puck Sealing
Post by: Grumpy on September 18 2018, 05:32:35 AM
RJC has a plate for that  :cool;
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