Redzone's how to DOHC your starion block thread

redzone · Post by **redzone** » Fri Jan 06, 2012 9:26 am

Snout length 26 vs 38mm, this is where the crank cam belt pulley goes on

OLD FART · Post by **OLD FART** » Fri Jan 06, 2012 9:43 am

Dave just to clarify things. Does it matter if you use a SN or LN crank in a single or twin cam build as long as you have the correct pulleys??
For example if say a TC came with a SN but it is stuffed and you have a LN can it be used or MUST you find a replacement SN crank,

jedi · Post by **jedi** » Fri Jan 06, 2012 12:29 pm

that helps i just about bought an vr4 rod's pistons standed., and an 7 bolt crank yesterday all came together but noticed the starion crank i got an is 6 bolt so wanna stay with 6bolt so can use my lighten flywheel and clutch because i guess if i used an 7 bolt crank i would have to buy new flywheel and and clutch to match crank., rang up the local mitis dealer just to get price on new piston and rod's and crank man what a rip off better off buying aftermarket parts.

OLD FART · Post by **OLD FART** » Fri Jan 06, 2012 2:58 pm

Just buy an Eagle Wiseco kit and you will be sweet as well as stronger & lighter
BTW the 7 bolt crank has smaller/narrower big ends BUT not sure if the mains are the same as a 6 bolt but I'm sure one of the resident gurus will be able to confirm :)

jk · Post by jk » Fri Jan 06, 2012 10:24 pm

Anyone know if the eagle 6bolt 100mm stroker cranks are short or long nose?

OLD FART · Post by **OLD FART** » Sat Jan 07, 2012 1:12 pm

jk wrote:Anyone know if the eagle 6bolt 100mm stroker cranks are short or long nose?

I have a 64 crank out of an Express cost me $150.00 +$60.00 for crack testing,checking bearing surfaces,straightness & linishing.It was perfect :D
PS have you em'd Eagle with your query or asked them if they can supply the crank you need yet ?????????

redzone · Post by **redzone** » Mon Jan 16, 2012 8:38 am

You can't use a sn crank with a dohc build as the dohc pulleys don't work with the short snout length..

All aftermarket cranks will be long nose, the only short nose equipped cars were early starion's & vans/utes with the 4g63 sohc

enthuzed · Post by **enthuzed** » Mon Jan 16, 2012 5:38 pm

I'm a bit confused by this: The 64 crank from the SOHC must be a really early 6 bolt which would then suit the Starion block. Problem with it is that the snout isn't long enough for the DOHC pulleys.

The later SOHC 4G64 was also a SOHC so suffers the same issue as above. But it was also a 7 bolt crank, and from what I understand it won't fit a Starion block.

The DOHC 64 block would then always be a 7 bolt crank and therefore also won't fit the Starion block.

Being 7 bolt cranks means they've got the girdle and all...

So which specific ones works for the stroker DOHC?

dirtygalant · Post by **dirtygalant** » Mon Jan 16, 2012 6:26 pm

I would say the later 88-92ish SOHC 8V 4G64 would have the long nose crank - if the same era SOHC 8V 4G63 has a long nose then so should the 4G64.

The SOHC 7-bolt 4G64 (1993ish onwards) is 16V with a wide cambelt (almost as wide as the DOHC engines) so also would have the long nose crank. The SOHC 16V 7-bolt in the L300/Express vans are also wideblock, and you could always modify your sump to clear the crank girdle.

redzone · Post by **redzone** » Mon Jan 16, 2012 7:49 pm

enthuzed wrote:I'm a bit confused by this: The 64 crank from the SOHC must be a really early 6 bolt which would then suit the Starion block. Problem with it is that the snout isn't long enough for the DOHC pulleys.

The later SOHC 4G64 was also a SOHC so suffers the same issue as above. But it was also a 7 bolt crank, and from what I understand it won't fit a Starion block.

The DOHC 64 block would then always be a 7 bolt crank and therefore also won't fit the Starion block.

Being 7 bolt cranks means they've got the girdle and all...

So which specific ones works for the stroker DOHC?

64 crank from a sohc 6 bolt are all long nose, they were well past the short nose design by then. notice how a lot of starions have chopped out the keyway in the crank? 9 times out of 10 they're a short nose..

the long nose crank sohc 6 bolt uses the crank timing pulley with the approx 10mm un-toothed section, early starions etc with the sn crank use the narrow pulley with no untoothed section..

enthuzed · Post by **enthuzed** » Mon Jan 16, 2012 9:22 pm

Cool Dave. Explanation clear. I'll double check that but maybe just start with a 64 6bolt block and crank. The squirters are a moot point because our pistons (whether factory or aftermarket) have no galleries to deal with the oil anyway.
For comparison, look at SR20 pistons. They have somewhere for the oil to go with factory ones but not at all for aftermarket. I'll find a photo to show what I mean...

enthuzed · Post by **enthuzed** » Mon Jan 16, 2012 9:29 pm

The photo, factory piston:

redzone · Post by **redzone** » Wed Jan 18, 2012 8:00 am

they're not there to lubricate the piston, they're piston cooling jets!

enthuzed · Post by **enthuzed** » Wed Jan 18, 2012 11:25 am

redzone wrote:they're not there to lubricate the piston, they're piston cooling jets!

Yes, that's right. The engine builder I was talking to reckons the squirters don't really provide that much of an effect.

I'd like that theory to be proved or disproved...Mitsubishi didn't engineer it for no reason though...

redzone · Post by **redzone** » Wed Jan 18, 2012 12:25 pm

Plenty of turbo motors getting around without them, they are a reliability aid though, help to stop pistons melting under extreme conditions..

Austarion

Redzone's how to DOHC your starion block thread

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