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Biggest valves for TFS streets?

1154 Views 4 Replies 5 Participants Last post by  rmcomprandy
what is the biggest intake and exhuast valves i can fit in the TFS streets?
they are 2.20 int. and 1.76 exh. in there now. if i can go 2.25 on the intake do i have to change the seats? i would like to go 2.30 or 2.35 onintake and 1.82 exh.

thanks
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I do not know how big you can go....but...2.250"/1.76" does work well ...w/o replacing the seats.
what is the biggest intake and exhuast valves i can fit in the TFS streets?
they are 2.20 int. and 1.76 exh. in there now. if i can go 2.25 on the intake do i have to change the seats? i would like to go 2.30 or 2.35 onintake and 1.82 exh.

thanks
You ain't going to make them into A-heads installing those valves. ;)

:D

Dave
Well the TFS seat i beleive are 2.30 and 1.80. If clipping wasnt a concern then a propper valve job i would think wouldnt be possible, no room for 60 degree cut. You would need a big bore so you could do alot of unshrounding to make a real differance. But i dont think you can run bigger then 2.25 and 1.76 without moving one of the guides angle . I have some TFS streets that best port flowed in the 380s with a 2.20 valve at only 700 lift. I would think 390 cfm @ 750 lift with a 2.25 is doable. Heads arent milled either which should help if done also. Could put a bigger seat on intake and downsize the exhaust is the only way i see it doable, alot of work for maybe a little hp?, dont know.,, Goodluck.., ED
On "out of the box" TFS heads I have used 2.300" intake and 1.770" exhaust diameter valves successfully however, the engine they were slated for had a rather small overlap camshaft.
I don't remember the clearance on those but, as long as there are .045" between the valves on the seats, a big cam can be used.
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