Portwork from Hell

[Roman]

You'll find most guys running stainless hardened valve seats are getting 1000 km's on a ti valve setup for the street. Berillium is the way to go but alot of headshops dont feel like getting fatally ill by breathing in the toxic material.

I will use either Nickel-aluminium bronze or cast iron seats as the Stainless is far too hard. 1000 km is approximately what I drive each year as we have a short season here. I live at about the same alutitude as Anchorage, Alaska and it is a weekend warrior, not a daily driver.

[Udo]

Roman, Ti valves are iffy on the street IMO unless your using Berillium valve seats.

I bought 8 brand new Ti valves from E-bay for $150 so it is a rather cheap test. If it doesn't work I'll just change.

Hi Roman

That is cheep . But if a valve breaks it will be very expensive !! 7 mm for titanium is a very big risc !! I like the 11/32 stem .They are strong and the keepers are very big !

Regards udo

[Roman]

These valves came from a Nascar team and they use them 500 miles full throttle with higher power output. Some of the top Nascar teams today even use 6 mm stems!!
Somebody got to try, that is what is driving technology forward. If everybody built engines like Berg we would have 7:1 compression and 90.5 bore...

[Rasser]

Somebody got to try, that is what is driving technology forward. If everybody built engines like Berg we would have 7:1 compression and 90.5 bore...

perhaps one day people will use T4 engines too    ;-) 

[ugly duckling]

nto. when i mean thik seat i mean small ID. thers 3 cuts on the seat 30/60/45. 60 is your first cut. i leave the ID small to create air speed. the more you open this area up and the port the less you have. i radius the 60deg angle on the bottem to a minimum. if the head comes with guide boss i leave it in( air speed excelirator) and better guide structure. alot of people will mow this out. then what you have is a port volume head. ive seen and done more heads that have flowed conservitly that have stomped on big # heads. torqe is what gets you down the track and street. goood cam choose and rod angle have alot to do with it also. but that is a totaly differnt subject. my thery is if you can make it down at a low rpm the better you are its not (wankle) its a vw but thats ME sure i love hearing a hi reving vw they sound bittchen how long they last is something else some people are RPM fanatics thats cool just my two bits. UD.

[Udo]

These valves came from a Nascar team and they use them 500 miles full throttle with higher power output. Some of the top Nascar teams today even use 6 mm stems!!
Somebody got to try, that is what is driving technology forward. If everybody built engines like Berg we would have 7:1 compression and 90.5 bore...

OK , that sounds good. But with this lightweight valvetrain you don't need much spring pressure .   

[ugly duckling]

one of these days jim. sometime this summer im sure.let me put my hillborn barrel valve system on. will have to see how streetible that set up is. will see . UD.

[n2o]

nto. when i mean thik seat i mean small ID. thers 3 cuts on the seat 30/60/45. 60 is your first cut. i leave the ID small to create air speed. the more you open this area up and the port the less you have. i radius the 60deg angle on the bottem to a minimum. if the head comes with guide boss i leave it in( air speed excelirator) and better guide structure. alot of people will mow this out. then what you have is a port volume head. ive seen and done more heads that have flowed conservitly that have stomped on big # heads. torqe is what gets you down the track and street. goood cam choose and rod angle have alot to do with it also. but that is a totaly differnt subject. my thery is if you can make it down at a low rpm the better you are its not (wankle) its a vw but thats ME sure i love hearing a hi reving vw they sound bittchen how long they last is something else some people are RPM fanatics thats cool just my two bits. UD.

So if I understand this correctly, you could have chosen a 49-50 mm valve, and still make the same numbers and airspeed? And if it was a SS valve it would be the same weight (as the TI you are using), it would be cheaper, and lasted longer (more street miles).

I am not trying to be rude, but I am trying to find out secret behind choosing the 52mm valve...

Thanks
Roar

[ugly duckling]

hello nto. i discoverd years ago when i use to use the flow bench on a regular basis that when you unshrowed the chamber intake side closest to cly wall to much you loose on the lower lifts 2/3/4. if you leave it choke up a bit like i have the lower lift cfm is there.( 52MM). dose this anwer your quistion.   UD.

[n2o]

Sorry UD  , maybe I'm slow learner, but I guess this effect is possible to get with a smaller valve also? Just unshrowed less, and you choke on lower lift, but you will still be able to make the numbers/speed above 0.400?

Thanks
Roar

[n2o]

Picture of the exhaust....