I was looking at using a sohc 16v head off a hj galant, but have also bought
a g4cp dohc non turbo engine [ which i believe is the same as the galant 4g63 non turbo ]
so i'm thinking can i use tie head on the 4g62 [as there appears to be less work involved using
dohc compared with the sohc 16v]
I rebuilt my 4g62 last 12 months ago so would prefer to use this bottom end rather than
rebuilding the nt 2ltr to turbo specs.
From what i can see i will need to get a vr4 ex manifold, and turbo cams? [ do i need ?]
The pistons in the 4g62 are the stock type but 1mm oversize and don't have the valve
fly cuts for 4 valves [ will this be a problem ? ]
I will swap the cam belt gears om crank and oil pump [ belt has round teeth not square and is wider ]
as well as the tensioner pulleys.
Need to mod top engine mount
What is the head chamber volume for dohc head ? If the compression is to high can i run 2
head gaskets to drop compression [ or is this a really bad move ]

Sorry for the long post.... i have searched but cant find much on this.... so any ideas appreciated
Cheers

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the twin cam head is interference so yeh you need the twin cam piston,
dohc pistons can go in sohc but not the other way round i was told

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"hahhahahhaa its good its got straw for a pipe frontn.... the bigger that hole gets the more money falls out of ur wallet... "



Epic i must say.

u can get multi layer head gaskets in diff thickness...dont run two head gaskets,,wont last long ..all the big hp cars use multi layer
also acl used to do custom pistons, maybe worth talking to them
and u will need to swap over all the pullys for the cam belts
also not real sure about sonata head fitting with oil drains lining up
best way is to compare the head gaskets
hope this helps cheers brian
opps ull find the sonata ports are diff to the mits head only slightly
but ud have to use a sonata intake manifold there closer to evo style
then the galant ones.
phew

Thanks for the replies.
I heard the dohc are interference engines, Don't want to get custom pistons as it
would be lots cheaper to rebuild the 2ltr sonata up
Sonata engine uses same manifold and head gaskets as vr4.
Will do a dumby build and plastigauge the piston to valve clearance
Have read that chamber volume of vr4 head is 47cc, my sohc 4g62 measures 49cc
so thats fairly close, will have to work out compression ratio
Will contact ACL if i need a custom head gasket

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you'll find that the intake gaskets off the VR4 fit the Sonata, RVR, and EVO123 but the vr4 has the bigest ports, then the Sonata, then evo 123. the head gaskests are the same (and on alot of other mitys for that matter).
cams, what ever fits without hitting the pistion. there are lots of people who use na cams in there turboed projects.

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with the battery in the boot at last!, next will be to get the rust out!

Cheers Aussie Babsy
but have to buy a new set of valves for head as they are all bent, this is how to get caught out
on ebay........................grrr

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You should not have a problem as the valves do not open whilst the pistons are at tdc. You will find that unless your timming belt slips there should be no problem.

NA cams will work fine. I have never used them myself but have been told they have shorter duration.

Anyhew im sure you will be rotating the assembly prior to startup. This will make it pretty obvious if there was any clash.

Hope this helps

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|VR4 4G63 RS|MicroTech lt8s|Ported TD06sl2-25g|Ported & Polished Head|HKS Front Mount|3" Exhaust|
|Coilovers|Swaybars|VR-4 2pot Calipers|TP rears|Evo3 Master/Booster|Evo 3 front bar|Side Skirts|Rear Lip|

Ummm... NO. This is not a worthless conversion. Upgrading to multipoint and 16valve is diffidently a mod worth doing.

Yes he will need to run an aftermarket ECU, this goes for all multipoint conversions and is easy enough to do.

No shit the entire front timing case will need to be removed. Dose this not apply to the removal of the standard head anyway? I’m sure even retards could work that one out.

LOL "just for a 1.8" whats that supposed to mean? I have a mate with a 1.8 GSR lancer making near 300kw ATW and that’s only a 1.8.

Doing a head conversion will most probably be under a quater of the cost for a vr4 conversion. so yes it is a worthy conversion.

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|VR4 4G63 RS|MicroTech lt8s|Ported TD06sl2-25g|Ported & Polished Head|HKS Front Mount|3" Exhaust|
|Coilovers|Swaybars|VR-4 2pot Calipers|TP rears|Evo3 Master/Booster|Evo 3 front bar|Side Skirts|Rear Lip|

HeavenSENT wrote


Nothing is worthless, the 16v head will flow more than the 8v so i will gain some
performance, but i do realise a 2ltr would also gain me more hp and torque but i'm
keeping it as cheap as i can. If money was of no concern i would have a rs200 or
lancia stratos to play with!! maybe a F40 aswell..........but thats a dream

1. I already have multipoint on this car therefor have a aftermarket ecu.
2. I dont have any of the plastic timing case covers on this engine ( so i just saved 15-20 mins)
3. The flycuts in the standard sonata pistons are very small so i believe there wont be a problem
but as TRQ-STR has said i will be measuring all clearances

I can see that having a mazda would make you an "expert", I know i asked the question
so can you tell me why it's worthless conversion as it should work out alot cheaper, time wise
i enjoy mechanics ( most of the time ). Why did mazda make 1.8 bpt engine?

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I have some sonata valves if you need.

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|VR4 4G63 RS|MicroTech lt8s|Ported TD06sl2-25g|Ported & Polished Head|HKS Front Mount|3" Exhaust|
|Coilovers|Swaybars|VR-4 2pot Calipers|TP rears|Evo3 Master/Booster|Evo 3 front bar|Side Skirts|Rear Lip|

Die in a pool of fire, troll.



Koray, it is Roger.

I have just reported him to moderators, so I have no doubt that he'll cop the full wrath of the banning stick in no time!

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Street/track spec Evo VI GSR in the making...

The head bolts on.
TRQ-STR have sent you a pm
I will only need to port match exhaust as have the sonata inlet mani already.

No worries about hijacking the thread ,
but if some people wish hang shit on others we don't need them!!
If there is good reason for doing or not doing a modification
i am happy to listen provided there is a valid reason for the comment ie
( i've tried that particular mod and the gain was not worth the effort as i got only 1% increase
etc )

Cheers

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I can't see why the head shouldn't fit...............if you use the bottom of the 1.8, keep the timing case and just replace the drive pulleys to suit the width of the timing belt and retain the standard tensioner what's the problem..........the conversion is worth a try.

hey guys just wondering how this conversion is goin sounds interesting

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GENERALLY SPEAKING, YOUR NOT LEARNING ANYTHING IF YOUR LIPS ARE MOVING

It's going slowly at the moment, the head i have needs to be cleaned up a bit
and i still need to get a 4g63 turbo ex manifold,
I will do a dummy bulid on an old engine soon to make sure all is ok [ cant foresee
any problems]
It will be interesting to see how much more [ if any ] power it will make and also
whether the torque curve changes much

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One step closer to the end...........
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A few years ago I calculated the air flow area through the valves of a dohc vs a sohc 4g63.
At the same valve lift, the dohc is approximately 40% larger than the sohc, however the dohc uses a smaller camshaft.
The final result of this is the dohc in stock form makes about 30% more peak power, has a better idle and better midrange due to the smaller spec camshaft.

So based on this you could expect at least a 30% increase in peak power as well as some increase in midrange.