Toyspeed.org.nz Message Board

by **trdfxgt** » Thu May 18, 2006 9:27 am

hi i have both a small port 16v head and a big port 16v head im trying to decide which im better to use the block is a super charged one so it has the oil drain tick for the small port head. also there is the tvis which from what i can see would remove most of the benifit of the big ports ?? i also have both inlet manifolds so again im unsure which will be best to use any thoughts ???
to add this is not about all out power i want good power but with maximum reliabilty i want to have around about 200 hp i have a good turbo and running the blue cams in which ever head i end up useing

by **Mr Revhead** » Thu May 18, 2006 9:35 am

whats the engine for?
rest of engine specs?
how boost you aiming for?

by **trdfxgt** » Thu May 18, 2006 9:40 am

engine is for racing so it will get worked hard but not reved above standed

Click here to see "My Black Hole" · by **Stealer Of Souls** » Thu May 18, 2006 9:43 am

I would have to vote for big port with no TVIS.

by **trdfxgt** » Thu May 18, 2006 9:45 am

how do i remove the tvis and if i do the inlet manifold still has 8 small holes ???

by **Drifter4ag** » Thu May 18, 2006 10:41 am

small port head gets my vote

by **EVLGTZ** » Thu May 18, 2006 10:48 am

Small port head gets my vote as well.

Only 200hp sounds like low boost application but since for racing will be hard worker etc

by **trdfxgt** » Thu May 18, 2006 11:40 am

200 hp @ the wheels if i can get it to much hp in a front drive means trac loss and with trac goes time

by **crnkin** » Thu May 18, 2006 1:29 pm

Definitely smallport, have a look at some of drifter 4ag's set ups on garage dori, smallport for sure.

by **Bazda** » Thu May 18, 2006 4:19 pm

big port

by **Drifter4ag** » Thu May 18, 2006 4:41 pm

yeah .. for 200hp at wheels stock redtop head would be awesome.
Bluetop cams
and not even that much boost

Click here to see "My Black Hole" · by **Stealer Of Souls** » Thu May 18, 2006 5:25 pm

Hmm...
I'm confused by the responses. Why do people say smallport head?

Surely if it's a racing engine you wanna optimise flows and efficiencies in the upper RPM band.
Max cylinder filling at upper RPM. So bigger ports for reduced pressure drop across ports/head?

by **sergei** » Thu May 18, 2006 5:36 pm

Bigger ports actually slow down the charge, the benefit of speed is that air has got inertia and with higher velocity more air will enter, thus taking advantage of longer duration (remeber the valve is still open when piston starts compressing the air, to allow more air to enter due it's inertia). Even with turbo the flow of air is not continous, so wave physics plays more than people give credit to.

by **crnkin** » Thu May 18, 2006 6:21 pm

smallport - smallport

SMALLPORT

by **EVLGTZ** » Thu May 18, 2006 7:40 pm

quite simple really aint it

by **crnkin** » Thu May 18, 2006 8:37 pm

SMALLPORT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

by **ezy10s** » Thu May 18, 2006 9:04 pm

small port will keep the velocity up in the port at lower rpm giving better responce.
as the engine is only 1600cc there is no real advantage to using the big port over the small port at all

by **crnkin** » Thu May 18, 2006 10:24 pm

SMAAAAAAAAAAAAAAAAALLLLLLLLLLLPORTTTTTTTTTTTTT

by **Mr Revhead** » Thu May 18, 2006 11:19 pm

bah use the big port, methanol, 45psi and aim for 600hp

by **Drifter4ag** » Thu May 18, 2006 11:24 pm

heres the bizzo ...
same setup

9.2:1 engine 14psi big port head was 176kw @wheels
same engine 8.0:1 small port head 183kw @wheels

nuff said

Toyspeed.org.nz Message Board

best turbo head what do you think

best turbo head what do you think

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