ShopTalk Forums | Aircooled VW Tech & Restoration Help

Do you think that this is needed for turbo applications???

Yes. The heat will destroy the part that is exposed in the port and it will come apart. When it comes apart it takes out your turbine wheel. $$$$$$$$$$$$

so, I only need to remove the exposed part? and not the whole thing?

NO. You should not remove ANY of the guide. The guide should be iuntact and complete from top to bottom. The exposed part of the valve stem will be exposed to stress it shuldn't have to, and will fail prematurely.

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*** Teach a Man to Fish ***
Searoy

"I tend to lean toward a tighter gap and a
looser skirt....a little slap never hurt." -- Joe of the West

Speedwheel - Yes only the part that is exposed in the port.

Searoy - Yes the valve will have less support and the guide will not last 50,000 miles. Thats the trade off with this performance stuff. If you only run 7# of boost and your motor runs real cool and is never raced or pushed hard, leave the guide alone. BUT.........
I have seen exhaust guides that look like peeled bananas in the exhaust port.
Just my $.02 and I let my performance speek for itself.

I had my heads reworked by 'the' head specialist from the now defunct Weslakes in the UK and he insisted on removing the exposed part of the exhaust valve guide. My motor has run consistent 12's and has done several thousand road miles with no probs, so far. Appart from solving the deterioration problem, the flow gained by removal is impressive.

Do you all think this would apply to an N/A motor as well?

For instance...lets say you had a pair of bastrd valve sized (40x32) 041's. If you were to smooth out/slightly port/remove valve guides all on the exhaust ports, would this even the flow numbers up a bit?

TomKettle

Go and read about this on Gene Berg's web site..good info... he sez never alter the exhaust guide boss, and besides there is little peformance gained even if it were 'safe' to do so.

Berg is ALWAYS referring to normally aspirated motors. We are talking turbos here and Berg never would condone the use of a turbo or nitrous. He did not think they are safe. The flow characteristics you are talking about do not take into account that the intake charge is under pressure. Much better flow without the guide under pressure. Also Berg is talking about the guide boss. FYI

So is it OK to remove the whole boss plus the guide to give the port as consistant a circumference as possible? Or remove ONLY the exposed valve guide above the boss?

My personal preference is to polish up the boss (but dont remove it) but cut the guide down to the boss. Most aftermarket heads dont have a boss in the exhaust port (FYI).
If you have 20,000 miles with the turbo, I would pull the header and give give the guides a good look every once in a while.
Also, I like to give the heads an inspection every 10,000 miles or so and most of the time the seats need a freshen up and sometimes guides (always springs). VW heads live in a very destructive environment as it is. When you bolt on that turbo you really induce a lot of heat and punishment.
If you now have 40,000 miles on that motor and everything is tight and good (leak down etc) I doubt you run much boost or push it very hard. Thats ok though. A good 2275 with 8 to 1 compression and 7 pounds of boost would make a very good running and reliable street combo that should last a long time. Just keep the heads fresh.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Marty:
<B>My personal preference is to polish up the boss (but dont remove it) but cut the guide down to the boss. Most aftermarket heads dont have a boss in the exhaust port (FYI).
If you have 20,000 miles with the turbo, I would pull the header and give give the guides a good look every once in a while.
Also, I like to give the heads an inspection every 10,000 miles or so and most of the time the seats need a freshen up and sometimes guides (always springs). VW heads live in a very destructive environment as it is. When you bolt on that turbo you really induce a lot of heat and punishment.
If you now have 40,000 miles on that motor and everything is tight and good (leak down etc) I doubt you run much boost or push it very hard. Thats ok though. A good 2275 with 8 to 1 compression and 7 pounds of boost would make a very good running and reliable street combo that should last a long time. Just keep the heads fresh.</B><HR></BLOCKQUOTE>

Marty, seeing how you do not know Bad62 and his driving habits or motor for that matter, I'll enlighten you. It's a 2110cc w/ CB hideaway (new version) and has never been babied nor has the boost been below 10psi. He beats the living poop out of it and runs it on long trips and many weekends with heavy highway runs and quite a few drag races on and off the track.

It all comes down to proper parts and building proceedures. Everyone has a theory and everyone has the answer, funny that way. I run a DLI blower on my 1776cc with heads from Fred Simpson and they are very similar to Berg's in many ways, and the guides are still there! NO PROBLEMS, after aprox 10,000 miles.(?)

Who really knows the answer here, but I'm convinced with actual experience as the proof.

Hope this helps.



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Build what you "want", then you'll see people "want" what you have built.

Great!
He has a very nice car and I am glad he has had no problems. I dont want anyone to have problems. I am also glad you have your guides in. I guess you dont have to worry about pieces of guide running through your turbine now do you? The person that started this thread asked about leaving the guides in in a TURBO application yet people respond with "leave them, Berg says so", and you with a SUPERCHARGER. What hapenned to the original intent of the thread?
If I had a supercharger, I would remove them there also but for a different reason.
Thanks for the help but I did'nt ask.
I'm fine.
Wanna race????????

hay marty what do you think would be better a supercarger or turbo on my automatic digger ? IYO

Give me some more details.
Drag racing?
Asphalt?
Sand?
Stall of the converter?
Legnth of car
Type of trans (Powerglide, 707 etc)
Heads up or bracket racing (if thats the intention)