JAS's Rebuild and twincam conversion. 302kw atw baby!!!

[enthuzed]

I've made a change to my previous post, the right four are castor rod bushes, no question. Sorry for any confusion, dirtygalant is spot on...we've both replaced them very recently so we both know what they look like...

[Junkers]

Wow it's really coming along well. Can you give us a run down of whats needed to convert to a b2600 gearbox? Are non turbo s4 gearboxes similar?

[JAS]

Wow it's really coming along well. Can you give us a run down of whats needed to convert to a b2600 gearbox? Are non turbo s4 gearboxes similar?

Most of the info is on Project Zero G. But heres what I know/ done.

I used a B2200 box as thats all I could find at the time. But a B2600 box made between 1987 and 1988 should be right. It will bolt to the wide block, the input shaft and shifter possion should be spot on.
A RX7 box with the B2600 bellhousing will bolt up but the shifter is about 6 inches further back than it should be. It can be moved forward but Im not sure if it can be shifted the 6 inches needed.

Heres what i have done to fit the B2200 box,

Bought a B2600 belhousing new from mazda.
Had the box stripped and checked. Replaced bearings, machine the input shaft as its to long, and had the back of the input shaft modded for better oil flow (bit of a week area in these boxes).
Ive also bought a new slave cylinder. Next Ive got to make the cross member once the box is in and bolted to the motor. It looks to be an easy job as the cross member mounts on the box are just about in the same spot as the factory starion.

Differences between the boxes that I know of are;
B2200 box has a longer input shaft that needs machining down.
B2200 and B2600 has the ratios most like the factory starion's. Also has the oil filler bungs higher as its designed to sit on an angle, as it will when fitted to the starion.
Rx7 box has the shifter 6 inches further back, but can me changed. Has taller gearing than the ute's and starion boxes. Will hold a little less oil when mounted in a starion(as above)
Each box seems to mount differently to the cross member as well. Even the S4 and S5 boxes are different.

I do remember reading somewhere that the RX7 boxes had better syncro's. According to my gearbox guy some boxes had a one piece syncro and some have a 3 piece syncro. But each box be it either RX7 or ute could have either. And you have to pull the box completely apart to see what its got. The 3 piece ones being a little better he did say that it made little difference and you can't swap the different syncro's between boxes.

All the boxes have the same spline on the input shaft and is the same as the starion. So you can use a starion clutch!!!
And even the speedo cable fits the Mazda boxes. But depending on the box the ratios will be out.

Then its just a matter of getting a drive shaft made up and your in business.


My brain hurts...... :roll:

[Junkers]

Cheers for that mate, excellent stuff.

Got a noob question for anyone out there. Can you use a evo 4 inlet manifold (the reversed type) instead of having to modify the evo 3 one?

[JAS]

Cheers for that mate, excellent stuff.

Got a noob question for anyone out there. Can you use a evo 4 inlet manifold (the reversed type) instead of having to modify the evo 3 one?

Yes you can. You have to cut a little off one end of the flange, But its an easy job.
You could also use the EVO4 on Exhaust mani, that would mount the turbo where the alternator is, which means relcating that. Not a bad job tho. And this way you can leave the power steer pump where it is.

[JAS]

Got the engine back :D



And putting the manifolds on

[FST4RD]

Very nice!
Now get it in the car and running :D

[groupAralliart]

So what are the details on the motor/turbo/intercooler sizing you are running. Looks great, you must be getting excited as you get all these bigger items finished.

[JAS]

So what are the details on the motor/turbo/intercooler sizing you are running. Looks great, you must be getting excited as you get all these bigger items finished.

Starion block, VR4 head, Wisco forged pistons, Eagle rods, balance shafts removed and everything balanced. T3/T4 turbo. 0.63 Ex and 0.70 Comp plain bearing. 38mm HKS Ex Wastegate. 4 paddle brass button clutch. Evo 6 560cc injectors, aftermarket fuel pressure reg. Link computer. Intercooler is a bar and plate item. A little longer than the standard one but much thinker.

Starting to get excited, but I think Ill realy get excited once the motors sitting the engine bay :D

[groupAralliart]

sounds like you have put together a very strong package. What boost levels are you looking to run?

[JAS]

sounds like you have put together a very strong package. What boost levels are you looking to run?

Not realy sure. Up to 20PSI I guess. But around 15 for normal use.

[S0LJAH]

looking good man

i thought u were guna run a 64 block?
or was i just dreaming that
should be a nice strong package anyways, running any cams?
i think thatl be my next mod

love the fact ur engine stand is 4g specific LOL

[JAS]

looking good man

i thought u were guna run a 64 block?
or was i just dreaming that
should be a nice strong package anyways, running any cams?
i think thatl be my next mod

love the fact ur engine stand is 4g specific LOL

Yeah I was going to run a 64 but chose the easier route. But looking back I should have just gone with the 64. Never mind...

Standard cams so far, but that will be an upgrade later on.

lol I made that engine stand cause I can't bolt a block onto my other one if the motor has a flywheel on it. Its quite handy as with a motor on it, it rolls under my bench :) :beer

[JAS]

Ive also been having dramas with the torque. But Ive found a great way to fix them.
Check this thread out http://forums.austarion.com/viewtopic.php?t=11125

[JAS]

Motor and box is in!!!!!!!





Tomorrows job is to make a gearbox cross member as the factory one is just not going to work.