Twin cam conversion donor engine

Neil · Post by **Neil** » Tue Mar 18, 2014 3:15 pm

Is it better to use a N/A Galant 4G63 or the Galant VR4 turbo - talking about all the accessories (alternator/p-steering etc) and the head.

Starion VR4 · Post by **Starion VR4** » Tue Mar 18, 2014 3:44 pm

Get the N/A... cheaper & you can't use the VR4 manifold anyway. :beer

OLD FART · Post by **OLD FART** » Tue Mar 18, 2014 4:46 pm

Remember they are both narrow blocks and you can't fit a Starion or RX7 box to them .
I used the NA Gallant GSR head,front cover and a Staz water pump on a 6 bolt wide block on my car

ProZac · Post by **ProZac** » Wed Mar 19, 2014 8:35 am

Use whatever is cheaper, but if you can find a small-port head, go for that instead. The VR4' s and most of the N/A stuff use tricky switchable manifold runners to keep air velocity high at low RPM, but also unrestricted at high RPM. The heads themselves have maaaahoosive intake ports. As you probably won't be using a tricky switchable intake manifold, your low RPM drivability will suffer with the big ports.

all EVO's and apparently some of the RVR's have the small port heads. Plenty of people are making massive power from the EVO's with pretty much untouched heads, so the smaller ports aren't going to hurt your peak power.

Don't limit yourself to just 4g63's in your search either, DOHC 4g61's from Marages/Colts, in either turbo or N/A form, will have all the accessories and head you need, it'll be a small port head too.

I've got a DOHC 4g67 from a 1990 Galant sitting downstairs to rob accessories, pulleys and engine covers from, it's got a big port head on it though.

JDSTAZ45 · Post by **JDSTAZ45** » Wed Mar 19, 2014 6:56 pm

Starion VR4 wrote:Get the N/A... cheaper & you can't use the VR4 manifold anyway. :beer

I trust you can use a VR4 cyclone inlet manifold on a N/A Gallant head with large ports? Or is it a no-go?? What's all this tricky air flow?
Will a tuner be able to dial/tune this low rev stuff out?

ProZac · Post by **ProZac** » Wed Mar 19, 2014 7:31 pm

The vr4 throttlebody is on the wrong end of the factory manifold. You could use it with some modification. The 'cyclone' part is a variable runner system, to use long runners at low engine speeds to increase air velocity, and short runners at high rpm to remove the restriction of the long runners. The system relies on vacuum diaphrams and such, and are mostly a bit stuffed by these days.

No amount of tuning will fix the problem of too-large ports, low air velocity and thus not as good cylinder filling at low to mid engine speeds. It's why manufacturers all switched back to smaller intake ports after the mid 90's.

However, most of this is just bullshit 'internet racing'. Find a twincam head, from a 61, 63, or 67, put it together and enjoy it :-).

As far as accessories go, yes, any DOHC 61, 63 or 67 motor will have what you need. You'll have to do some custom work to make it all work anyway, so if something doesnt fit, you get to come up with ingenious methods of making it. :-).

ProZac · Post by **ProZac** » Wed Mar 19, 2014 7:35 pm

Please note: Take what I say with a grain of salt, as I'm just back from dinner at the in-laws, and am about 8 ciders deep. On a school night none the less!

Starion VR4 · Post by **Starion VR4** » Wed Mar 19, 2014 7:57 pm

JDSTAZ45 wrote:
Starion VR4 wrote:Get the N/A... cheaper & you can't use the VR4 manifold anyway. :beer
I trust you can use a VR4 cyclone inlet manifold on a N/A Gallant head with large ports? Or is it a no-go?? What's all this tricky air flow?
Will a tuner be able to dial/tune this low rev stuff out?

Yep for sure... as for tuning it out? I can be done. :beer

fugazi · Post by **fugazi** » Wed Mar 19, 2014 8:37 pm

My (on the shelf) 4g61 DOHC-head has an intake-port bigger than the EVO, but smaller than the 4g63 (galant GTi)... which will make it trickey to use without a matching intake-mani.
And the cumbustionchamber is smaller than the 63-head.

And... there are a couple of Hundai-heads useable too.

And then there's the EVO4-> motors for u RHD-guys.

Neil · Post by **Neil** » Wed Mar 19, 2014 10:00 pm

How about the RVR HyperGear? Isnt it meant to have (basically) an EVO 3 donk? Could this engine be used as a head and accessories donor as well?
I have read it may use a crank & cam angle sensor as well - but would this even matter in our situation? As I would be converting to rwd and using an aftermaket ECU?

redzone · Post by **redzone** » Thu Mar 20, 2014 7:43 am

If you can find the rvr motor with the front mounted cam angle sensor then grab it with both hands!

Starion VR4 · Post by **Starion VR4** » Thu Mar 20, 2014 6:43 pm

Neil wrote:How about the RVR HyperGear? Isnt it meant to have (basically) an EVO 3 donk? Could this engine be used as a head and accessories donor as well?
I have read it may use a crank & cam angle sensor as well - but would this even matter in our situation? As I would be converting to rwd and using an aftermaket ECU?

If you get an RVR head, I will swap youa VR4 head with cams !!! :beer

thrash · Post by **thrash** » Fri Mar 21, 2014 11:51 am

ProZac wrote:The vr4 throttlebody is on the wrong end of the factory manifold.

This is a little confusing to me.. don't all the early gen dohc intake manifolds have the throttle body on the wrong end?

Neil · Post by **Neil** » Wed Mar 26, 2014 7:48 am

Thanks for all the comments.

I have tracked down an RVR hypergear engine.
I asked if it had a front or rear CAS. The guy said did I want a rear or front CAS on it as he has both...and that you can place a plug over the rear.

Now I got some pics and it looks like it had a rear CAS.

Does anyone know if you can have either on these engines? ie change from front to rear and vice versa if you have all the hardware?

Starion VR4 · Post by **Starion VR4** » Wed Mar 26, 2014 4:44 pm

That pic is a rear CAS engine, no you can't change it from front to back without welding & doing some machining. If it was me I would get the Front CAS engine. :beer

Austarion

Twin cam conversion donor engine

Twin cam conversion donor engine

Who is online