Austarion

Hi there, what is the general feeling on the strenght of the sirius dash bottom end? (is it any different than a normal sirius?) also i've tried searching but not yeilded any useful info as to whether vr4 rods are compatible or for that matter worthwhile to put into a sirius block with the intention of building a (very) strong dohc motor.

at this stafe i have an N/A dohc motor but am looking for future options.

AFAIK the DASH engine is a normal SOHC 4g63 with a 12 valve head, thats the only difference. And yeh I think VR4 rods (and pistons for that matter) will fit any 2L SOHC...they are far stronger too.

yeh I think VR4 rods (and pistons for that matter) will fit any 2L SOHC

Okay has any one done this and can back it up?

Thats what i want to know as well. at this stage my plan consists of: balance std dash crankshaft, vr4 rods, forged slugs, DOHC N/A head, big mother turbo (dunno what yet, open to suggestions) external WG yadda, yadda, yadda. you get the idea anyway..

gotrice? wrote:

yeh I think VR4 rods (and pistons for that matter) will fit any 2L SOHC

Okay has any one done this and can back it up?

VR4 Rods 99.9% certain, would need VR4 rod to sample any weight/metalugical differences, but looking like DASH Pistons until I have a VR4 Piston to double check from what I can tell going by photo's, they are two different pistons.

theyre def different pistons, dash has 3 valve releifs, vr4 has 4, i am interested in the sizes of the wrist pins and also bearing journals, if they are the same then its a straight swapover job if not then things get hairy..

A DASH motor has forged pistons too. :drool:

Guys I'm fairly certain a DASH engine is very similar, if not the same as a 4G63 VR-4 16 valve bottom end. It sounds daft I know, but the pistons have indents for FOUR valves. The DASH engine was pretty much an R&D engine for the 16 valve VR-4 engine. The internals are somewhat strengthened to allow it to run the 12~14psi factory boost it does.

These are a brilliant engine. Thats what i have in my Starion, on 15 psi and 7000rpm cut. I cant get enough of these engines and the bottom ends dont need to be changed at all. These babys with a TC06 and T3 wheel are a weapon.
They do need an adaptor plate for the staz box however.

has the dash got the girdles accross the bottom of th crankshaft from no1 main to no2 main and from no4 main to number 5 main? also does anyone have the size of the big ends and also the wrist pins.

vr4 sizes:big end OD 45mm

wrist pin OD 21mm

note these are factory sizes as specced in chiltons.

i have a DASH motor in my cordia, fitted with VR4 rods, VR4 RS pistons, full rebuild. main thing i dont like is on 13psi it was making peak power at 5200rpm it is running very rich (got to 10.8 afr before backing off at 5500rpm). would this just mean i need a bigger turbo and more boost? (and a tune to sort out the richness obviously, running microtech ecu).
cyas

85_cordia_gsr wrote:i have a DASH motor in my cordia, fitted with VR4 rods, VR4 RS pistons, full rebuild. main thing i dont like is on 13psi it was making peak power at 5200rpm it is running very rich (got to 10.8 afr before backing off at 5500rpm). would this just mean i need a bigger turbo and more boost? (and a tune to sort out the richness obviously, running microtech ecu).
cyas

get an aftermarket engine management system and tune it.

ive got a microtech mt-8 already.. jus needs a tune.. made 117kw@13psi in current tune....very rich..

did you build the motor in your cordia? were the rods bolt on ? or did you have to do sopme machining?

the rods were bolt on, exactly the same :)