20 valve heads

[Luv_my_mk1]

I was doing reserch on the 4age 20valve and was wondering if the head would fit on the 3sgte block. I have found nothing yet but thought it might work. Also i didnt know how much the compresion ratio would be affected since you have a 2.0 block with 1.6 heads. Any segesttions helpful. Thanks

[Driftin_AW]

no it wont fit

[Paul Woods]

nonne of the 4a series stuff will work on the 3s series as malcolm says.

[superchargedsam]

the 4AGE engine was designed by Yamaha especially the head design and the 20v head comes from thier motorbikes as they all use the 20v design on these engines ! The 20v head is superb but you will never get the power from one of these you will the 3SGTE without massive amounts of money thrown at it !

[adamh]

lets have a sneek peek at the comp ratio if you did that, all theoretical of course and only based on comp ratio's and strokes found on the net.. so it could be a tad out.

using this wee regular formula :D :bounce:
pi x bore sq
--------- x stroke = vol of cylinder in cc's
4

4age 20v comp ratio is either 10.5:1 or 11.0 : 1 for the sake of it..i'll go inbetween at 10.75:1
3sgte comp ratio i think is 8.8:1 i'm not sure exactly.. just info found.

4age bore/stroke 81 x 77mm comp 10.75:1
3sgte bore stroke 86 x 86 comp 8.8:1

assuming both headgaskets are 1mm.

4ge sum:
3.141592654 x (bore squared)
---------------------------- x stroke = single cylinder vol
4

~ pi x (8.1sq)
----------- x (7.7) = vol = 396.780796 cc's
4

ok..so 4age single cylinder is 396.780796 cc's.. multiply that by 4 = cubic capacity of block.. 1587.123184 cc
heres the trick.. divide 1587.123184 by 10.75 then by 4 ,
in theory it should give the volume of a combustion chamber.. as we are compressing the volume in the combustion chamber arent we..
so..
(1587.123184 / 10.75) / 4 = 36.90984149 cc's per comby chamber vol.
inclusive of headgasket, as we assume they are both equal.

3sgte sum.
3.141592654 x (8.6sq)
---------------------- x stroke (8.6cm) = 499.5572142 cc's per cylinder
4

x 4 = 1998.228857 cc of block

divide by 8.8 then by 4 = 56.76786525 cc per comby chamber

got both the comby chamber volumes now, and the block capacitys..
4age 1587.123184cc comby vol 36.90984149 cc (x4)
3sgte 1998.228857 comby vol 56.76786525 cc (x4)

so.. lets stick the 4age head on the 3s block and see what comp ratio turns out to be..
1998.228857 / (36.90984149 x 4) = 13.53452613

there it is.. a comp ratio of 13.53:1
me thinks it blow the head off :D
if it were to fit.

[Paul Woods]

:ha: the guys a genius! mmm now the head blowing off a mk1,that would make a good vid!

[adamh]

thats without the reduced intake temp + compression from the turbo aswell :shock:.. nov 5th just gone , save it till next year :lol:
thats another quesy aint it.. what does the ct26 increase the compression rat too, and thinkin about it.. why does a turbo give better a better power increase.. i thinks i see now.. it adds a power band to the cycle if you like (reduces its normal timed duration if it were sc) , and shifts it up the rev range so you get an injection of compression further up the range.. i wonder why the added compression dosent work lower down in the rev range :-k .. i xperimented before with having the t-vis in my 4age full on through the rev range and the increased air intake by pulling the tvis vsv pipe out of the tvis rail. just killed the power low down.. why is that?..is it a mixture thing?
mayb its because the momentum & torque/weight of the 1.6 / 2.0 aint enough low down to compress the turbo induced extra air.. i guess that may be why the regular motors to supercharge have big litre-age and a v formation cylnder which gives a better torque angle.. who has the answers :D? :-k

[Paul Woods]

i believe its a flow thing rather than a mixture thing adam...more restriction in the inlet makes it suck harder im presuming.

[adamh]

thats another way of looking at the tvis system..its strangled :lol:
its too much aint it!.. i'll stick with the comp ratio :lol: before i spend a week crunching numbers.

[Luv_my_mk1]

Thanks guys. I just figured if u could put the 20 valve on the 3sgte then that would be one amazing powerplant, but i dont really feel like spending $400 on the head to see it go through my engine cover. Although that would be a sight to see.