here at WPVW we are experimenting and developing a modified type-4 cylinder head that has type-1 style exhaust ports so that we can get a larger volume of exhaust gas out of the engine without having to squash the exhaust tube between the pushrod tubes . we have seen the pauter and the remelle heads that cost US$3500 , but not very often you have a spare AUD$5500 just lying around that you can spend on heads . Our heads should be a much cheaper alternative and we will personally test them when they are completed . will keep you posted on our progress .
first pic shows the origional exhaust port welded-upnn[ Edited on 13-8-2005 by hypo-vw ]
Craig Torrens wrote:Are you looking at casting a whole new head, or individually modifying standard heads?
most definately looking into casting our own heads , but haven't been shocked with any prices yet . Will finish 1 pair of modified heads and test them first so that the engineer knows what we are after . He is a very clever man , I saw him make his own V-twin 1100cc 2-stroke engine for a speedway sidecar about 9 years ago . He had his own engine case cast and started from there . It was a huge success until the rider was thrown and got very badly injured . nothing could catch it !!
my uncle told me about that bike.... he runs in the vintage speedway circles in Adelaide, said it was an incredible machine. Sounds like the bloke has his head screwed on right !!!
My father Richard Holzl many years ago went into doing the same thing and made samples to have them cast but pulled out after it was going to cost way too much to finish it off. I think we still have a wooden head with the T1 style exhaust port somewhere.
My father Richard Holzl many years ago went into doing the same thing and made samples to have them cast but pulled out after it was going to cost way too much to finish it off. I think we still have a wooden head with the T1 style exhaust port somewhere.
alex
Yeh Alex i remember your dad showing me that wooden head,JVLRacing
My father Richard Holzl many years ago went into doing the same thing and made samples to have them cast but pulled out after it was going to cost way too much to finish it off. I think we still have a wooden head with the T1 style exhaust port somewhere.
alex
Thanks Alex , I will give him a call tomorrow and see if he can send it to me . Always open to fresh ideas . I spoke to the engineer today and all he needs me to do is finish 1 head to send to him as a sample , and your right , it wont be cheap to set up . I still think that it is a worthwhile propasition though . Will keep ya posted .
This is fun to see. Same problems, same ideas and similar solutions.
In Sweden I did own a TIV engine with seriously modified exhausts to T1 style. The heads were inspired by the rallycrossers who did this type of exhaust modification and also on some they put on watermantles around the cooling fins.
My engine had both.
Second set of heads were traded to me and had MIG welded T1style exhausts. This head was never "stable" with seats moving around. I guess it was simply done in a too rough way. No pre heating and no aftercooling.
If done professionally, it is definatly possible.
A friend of mine in Sweden was so pissed off with quality and design of the T1 heads available....and the prices when in Sweden, that he has cast his own heads. They look really nice and flow like hell right out of the box even before porting. Still in prototype stage but it is just another example of that it can be done if you are motivated.
Good work to keep the aftermarket vw industry moving ahead and improving. I for one would love some better flowing heads for my type IV so hopefully one day they may be available.
Not type 4 heads but apperantly Johannes is now official with his new castings that Ireferred to.
Check it out and his totally stock looking sleeper running 12 s and Keihin carbs. Wheelstander on a good track. this guy knows how to build VW's.
nice eye candy there guys, I like! I like alot :bounce
I'm curious to know if anyone has any alternate suggestions for the down facing exhaust ports for people who want to stay with the pancake cooling? The only things I can think of are tappered pushrod tubes such as what some Harleys run then just inserting some sort of bushing where the pushrod tube sits in the heads. Does anyone think this would create running problems in anyway?
The only other thing I can think of involves casting a whole new head and having the exhaust port sit flush with the base of the head a'la 911 heads, however the pushrod housing on the ends would need modifying. I'd photo-opped a type IV head pic (pain in the arse to find an underside shot in the first place) so show what I'm thinking, but again you would have to drastically decrease the size of the pushrod tubes.nn[ Edited on 19-8-2005 by Cam ]nn[ Edited on 19-8-2005 by Cam ]
I would have thought that head strength is the biggest improvement required.
I don't think the exhaust port is that much of an issue. No, they don't flow as much as a type one port, but that can be worked around with camshaft if required.
Adams streeter shows that the N/A potential is there, and any thing turbocharged always goes fast with correct tuning.
I think the photo that Dave posted is of a type one, cause the T1 rocker cover wont fit the T4 valve spacing considering the cylinders are further appart also.
I think the scat splitport heads can be ordered to fit T4s.
westi wrote:That's mad Alan.
hypo-vwAustralias 1st 10sec street beetle (Jan 2007) 10.49secs@132m
dangerous wrote:I don't think the exhaust port is that much of an issue.
Dave the most major issue that I find with type-4 heads is the exhaust port is far too small for large capacity engines . The guys that run much smaller type-1 engines have the same size ( and sometimes larger ) exhaust ports . There is just not enough thickness in the factory castings around the type-4 exhaust ports to enlarge them to a decent size . Even if you could , the second problem arises , and that is getting decent size primary exhaust tubes out between the pushrod tubes . And then the third problem is the valves are too close together to get a large enough exhaust valve when a 48mm inlet is used . If you consider the volume of gases from an engine with bore size of 105mm , trying to squeeze through an exhaust port of just 38mm , it just isn't efficient . Far from it !!
As far as adam's streeter , it is a credit to him . but if you remember back to 1996 , we were doing 12.8 on the quarter with our 1962 streeter with no slicks . we ran the car on 165/15 kuhmo radials . HEADS ARE STILL THE LIMITING FACTOR ON TYPE-4 ENGINES .
