4age 20v head vs 16v head... Big cams and serious flow

[Prime86]

I would think welding the floor if not done very carefully you could warp the whole head. This would be a long process and everything would have to be checked to ensure nothing moves.

They only tend to lift the floor in the intake ports for better angle the exhausts seem to be fine. They leave the floor in the exhaust and tend to go wider and higher. This works really well and if you look straight down the exhaust port you can see the seat clear as. As far as the intake goes you can use a normal intake manifold as such then simply redrill the holes to lift the intake manifold to suit the port angle and port it to suit.

[MAGIC MAN]

no i would never attempt to to weld the port floor that would as you say warp the head beyond being useful. Devcon will be used to fill the port to the desired level. I've seen and read so many theories, discussions at work have even been a little heated as the head war heats up, lol. I want to go a little smaller than what the others are saying. I ultimately want to eventually boost the engine later on down the track so i know bigger wont effect that.
Standard manifold???? is definitely not up for the job on this head, my manifold needs to be as short as possible.
Engine will be dry sumped, TRD dry sump pan has already arrived. Standard length rods will be used to start with then i may change to longer rods later.

[Prime86]

Devcon is fine on the floor of the intake, Sorry must have misread your other post. As far as what I said about a standard manifold I mean an aftermarket quad manifold either injected or twin carb you don't need a custom built manifold that follows the angle of the port to suit as such. Lifting the manifold and redrilling the holes will go a long way to helping with flow into the ports.

I guess if the right questions are asked you get the answers. As far as what I know about heads and what your trying to achieve with yours I have already done it. I have a bare head that is already done to the specs your trying to achieve and the same way lifting the floor of the intake port etc. I know lifting the intake manifold work because its been done on mine. Also the intake ports aren't massive it was more about velocity into the intake port. Exhausts have been very carefully done also but are very large, combustion chambers have also had a lot of work.
Good to see your having a good crack at it and I hope you reach your goal.

[MAGIC MAN]

thank fingers crossed, hopefully i'll get the head on the flow bench this weekend some time and do some testing, i'm lucky as i can measure velocity and cfm, despite the ports seeming big, when compared to other engines looks can be deceiving. if you don't mind me asking how far did you lift your ports? and what sort of figures did you see?
as for intake manifold although what your say would be quite simple, i simply can't do it due to the fact the port is too wide for the manifold

[Prime86]

The floor was lifted up to 12mm where it blends with the intake devider and the lowest part of the port is roughly 6mm higher than stock.

Maybe these will help to see how high and what was done, it was a little hard to get really good pics.

[MAGIC MAN]

nice, so yours is a smallport? well started as one by the looks of it. What did you use to get your port finish like that? I thought you may have went higher on the exhaust port. Looks good though as that is pretty much where i'm going with mine just a bigport though.

I've been flat out this week at work and haven't had any time to spend on the head so i'll have to wait to finish porting before i flow it and test port velocity.

[Matt]

Found this and thought I might share...

[Matt]

Another interesting link on trumpets and the use of bell mouths and affects on flow