Dohc pistons in sohc

niss720 · Post by **niss720** » Mon Jun 03, 2013 11:18 pm

Hey I'm sure this has been asked a thousand times, but can you use vr4 or dohc forged pistons under the 63 sohc head?

bigmoz · Post by **bigmoz** » Tue Jun 04, 2013 12:25 am

OLD FART · Post by **OLD FART** » Tue Jun 04, 2013 6:06 am

bigmoz wrote:yes

More info The 4v heads are interference =Valves will get intimate with pistons if belt breaks .That won't happen in a SOHC 63/64 so VR4 pistons are ok

redzone · Post by **redzone** » Tue Jun 04, 2013 10:56 pm

It's something i've been telling everyone to do for 7 years.. The benefits are many, i cant believe anyone would actually buy starion pistons when you can get VR4 pistons cheaper and they actually dont break ring lands anywhere near as easy...

ProZac · Post by **ProZac** » Wed Jun 05, 2013 12:53 pm

What sort of compression ratio do you end up with when using VR4 pistons with an 8V head?

niss720 · Post by **niss720** » Wed Jun 05, 2013 6:58 pm

Thanks guys and what compression ratio would 9:0:1 pistons bring with the sohc

pajeroturbo · Post by **pajeroturbo** » Thu Jun 06, 2013 7:12 am

Once I have just finished my engine today I will tell you the whole story.
I have a pajero 89-90 model and I am using a starion motor in it for 10 years now.
The engine is stock motor with a tc-06 turbo. Before 5 years I did a full rebuild of the
Motor and used the 16 valve pistons everything fits ok and the car made 241 hp on 1 bar boost using a haltech e8 and a multipoint injection from the 4g64 motor. With these pistons the engine has a 7.2 compressor ratio and that makes the car having no power on off boost
Last week I decided to change the pistons and put the pistons the l200 used with the1mm dish that makes the compressor ratio to 9.5 I did a drive with the car and man the car of boost goes crazy good. Boost comes up very faster than before. The only thing is that I do not know how much the pistons will last with this set up. If there is anything you can tell me please say it with no problem.

DrDeath · Post by **DrDeath** » Thu Jun 06, 2013 3:33 pm

Im running the 9.0:1 CP pistons on decked block and head with .6mm gasket i think. I think that gives me around 7.9:1 compression. Problem is I don't know how much they took off the head. Its a non jet valve 8v head too. Don't know if that makes a difference to the size of the combustion chamber? Stock length rods and stroke too.
Doesn't feel sluggish off boost anyway.

niss720 · Post by **niss720** » Fri Jun 07, 2013 6:30 pm

So the comp will stay low with any piston under the sohc head. But good to know! thanks for all yor help guys!

Austarion

Dohc pistons in sohc

Dohc pistons in sohc

16 valve pistons

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