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Engine Specific Info and Questions => IDI Engine => Topic started by: rallydiesel on July 01, 2009, 06:34:32 pm

Title: Bigger valves for frankenmotor?
Post by: rallydiesel on July 01, 2009, 06:34:32 pm: Has anybody found larger valves for the AAZ head that are ready to use? I'm watching a similar topic at tdiclub but people here often have a better knowledge base on the fringe stuff. I know I am obviously going to need to enlarge the valve seats but I'd like to be able to use the stock valve guides. I would like to avoid custom valves if possible.

Any info out there?
Title: Re: Bigger valves for frankenmotor?
Post by: rallydiesel on July 11, 2009, 02:45:17 pm: If I used 2 mm larger valves, would I need new, larger seats, or would the stock seats be able to be ground?
Title: Re: Bigger valves for frankenmotor?
Post by: RabbitJockey on July 11, 2009, 03:06:42 pm: i believe a few people on here have done it. but i have nothing to share other than that
Title: Re: Bigger valves for frankenmotor?
Post by: andy2 on July 12, 2009, 08:32:02 am: I would not bother up sizing the valves unless you have a big turbo to go with them.What size turbo are you using?
Title: Re: Bigger valves for frankenmotor?
Post by: Rabbit on Roids on July 12, 2009, 11:02:56 am: Quote from: rallydiesel on July 11, 2009, 02:45:17 pm
If I used 2 mm larger valves, would I need new, larger seats, or would the stock seats be able to be ground?

im pretty sure the stock seats wont take a +2 valve. what difference would it make what valve you have in there if you have the same size seat. it still has the same size hole underneath the valve. doesnt make much sense to me to use a stock seat with a huge valve.
Title: Re: Bigger valves for frankenmotor?
Post by: rallydiesel on July 12, 2009, 12:51:10 pm: Quote from: andy2 on July 12, 2009, 08:32:02 am
I would not bother up sizing the valves unless you have a big turbo to go with them.What size turbo are you using?

I don't have one yet but I am planning on going big. Either large vnt or possibly compound. I'm just putting this engine together gradually. I was on the techtronics site and they have a few oversized 8v hydro gasser valves.
Title: Re: Bigger valves for frankenmotor?
Post by: Rabbit on Roids on July 12, 2009, 12:56:31 pm: hydro gas valves wont work. dont mean to burst your bubble.

but it just wont work. no matter what.

you need diesel valves. they are alot longer than gas valves. and im pretty sure the diesel exhaust valves are sodium filled.
Title: Re: Bigger valves for frankenmotor?
Post by: rallydiesel on July 12, 2009, 02:03:41 pm: You're not bursting my bubble. I'm asking to get info. I guess I'll have to check into stainless blanks then. Sodium filling is not important to me.
Title: Re: Bigger valves for frankenmotor?
Post by: carrizog60 on July 12, 2009, 03:43:55 pm: g60 valves are also sodium filled.
dont know if the size is right... ::)
Title: Re: Bigger valves for frankenmotor?
Post by: 8v-of-fury on July 12, 2009, 04:58:19 pm: Why are they sodium filled? what does that help with? strength and heat dissipation?
Title: Re: Bigger valves for frankenmotor?
Post by: rallydiesel on July 12, 2009, 05:02:09 pm: As far as I know, heat dissipation. Which is strange, because stainless steel valves are often used in high performance gas heads and they run hotter exhaust manifold temps.
Title: Re: Bigger valves for frankenmotor?
Post by: 8v-of-fury on July 12, 2009, 05:06:52 pm: are these diesel valves stainless steel AND sodium filled? if not SS what are they made of?
Title: Re: Bigger valves for frankenmotor?
Post by: Aki-76 on July 12, 2009, 09:25:42 pm: My new twinturbo engine use 41mm intake and 36mm exhaust valve,both are ceramic coated.
http://s434.photobucket.com/albums/qq68/Aki-76/moottorin%20osia/?action=view&current=13042009348.jpg

This valve is N2 41 stainless steel,very hard stuf.

Early engine use bmw valves,39/34mm,and whit 2.6 bar boos reduse about 200kw.
Title: Re: Bigger valves for frankenmotor?
Post by: rallydiesel on July 12, 2009, 10:00:45 pm: Are those from blanks? What diameter are the valve stems? Did you get new valve seats? Any more pics of your cylinder head?
Title: Re: Bigger valves for frankenmotor?
Post by: rabbitman on July 13, 2009, 12:38:29 am: Quote from: 8v-of-fury on July 12, 2009, 04:58:19 pm
Why are they sodium filled? what does that help with? strength and heat dissipation?

The sodium is in the length of the stem, it melts at running temp and bounces up and down carrying heat from the valve head up to the cylinder head keeping the sealing surface from melting.

If you find a junk sodium valve cut a notch in the stem and throw it in a bucket of water, it reacts and bubbles lots. ;D
Title: Re: Bigger valves for frankenmotor?
Post by: Aki-76 on July 13, 2009, 01:11:33 am: valve is aftermarket,and extra long.about 9mm longer as orginal and i use difrend kind spring.valve stem are 42/36mm,very hard stainless steel 21 4N.
Good but costly :-[
Title: Re: Bigger valves for frankenmotor?
Post by: Rabbit on Roids on July 13, 2009, 10:57:44 am: just keep in mind that VW gasser valves wont work. period.
the gas heads have an actuall combustion chamber in the head. and the valves are recessed up into the combustion chamber. so for them to be the right length to touch the cam, they have to be shorter than a diesel valve, because we have no combustion chambers, except for our prechambers, therefor making our valves longer.
Title: Re: Bigger valves for frankenmotor?
Post by: subsonic on July 13, 2009, 06:20:56 pm: Found this site a while ago and saved it for future day dreaming.
These guys have it all.
Stainless backcut polished sodium filled etc. Super high speed.
Read and drool! ;D
http://ferrea.com/index.php (http://ferrea.com/index.php)