bigger valves

[TheProfessor]

hey does anyone know if the gen 3 heads can be ported for and fitted with larger valves and if so where such valves would be available

[robby1870]

3400 heads have the 1.76 intake valve, but exhaust is still 1.42. Im not sure how to go about fitting bigger valves, but given how close the valve seats are to one another, there's not much room.

[TheProfessor]

yeah i know they are close but so are the gen 2

[TheProfessor]

ok so far what i have found out is that there is are 1.3mm oversized intake and 1.5 oversized exhaust valves when i find out more about them and whether or not they will be usable without major mods ill post

[RacerX11]

See my post in this thread regarding searching for bigger valves: http://60degreev6.com/index.php?name...424&highlight=

Marty

[smilinguy99]

Here's a link that shows just how much room there is to put bigger valves in a GenIII head:

http://www.novia.net/~sparks/heads/GEN3_HEAD_PARTS.html

[TheProfessor]

ok heres what ive found out
you can get oversized valves of 1mm larger for both the intake and exhaust
they can be used without any modifications to the head
so thats 1.8 intake and 1.46 exhaust
now im wondering what the result would be in using these size valves

[RacerX11]

If you don't modify the head by enlarging the throat of the valve seat, or installed larger seats, you won't gain any flow....you will probably end up hurting flow.

Marty

[TheProfessor]

yeah well youll have to do that stuff in order to take advantage of them
what i ment was that they would drop right in and not cause any interference problems

[bszopi]

Any interference seated or during 5k+ revs?

[v6h.o.]

ok heres what ive found out
you can get oversized valves of 1mm larger for both the intake and exhaust
they can be used without any modifications to the head
so thats 1.86 intake and 1.46 exhaust

Woah. slow down there trigger.. Your comparing apples to oranges.

1.76 is INCH. = 44.704mm, thus 1mm oversized valves(which are made to replace valves that in heads that have worn out valve seats so that the new seat can be cut slightly larger) would equal 45.704mm in orange form which then equates back to the apple form of 1.799 inch, which is just .039 inch larger than stock. get a feeler gauge out and measure this amount.

[TheProfessor]

no interference unless both valves are at .400 inch lift or more at the same time
which should never happen unless there are problems with the valvetrain

colin.....so are you saying that it wouldnt be worth trying out larger valves
and what do you mean apples and oranges

[v6h.o.]

no interference unless both valves are at .400 inch lift or more at the same time
which should never happen unless there are problems with the valvetrain

colin.....so are you saying that it wouldnt be worth trying out larger valves
and what do you mean apples and oranges

intake valves are 1.76inch. you posted 1mm oversized valves =1.86 inch i was simply pointing out you were confusing two different forms of measurement and getting them all jumbled around. 1mm oversized equals the number you now edited your post to as i pointed out..

[TheProfessor]

oh ok gotcha
didnt know what you ment
yeah just made a mistake when typing 1.86

[TheProfessor]

Here's a link that shows just how much room there is to put bigger valves in a GenIII head:

http://www.novia.net/~sparks/heads/GEN3_HEAD_PARTS.html

where did you find this
anyway to contact them