Grrrrrrr!'s Sw20 Tracktoy

[spyderballer]

Hey what cage do you have in your mr2? Looking at options for mine cheers

[Grrrrrrr!]

A shit one, was in the car when I purchased it. Not tied to the body in enough places, does't huge the pillars well enough either, and some muppet made the side intrusion bars removable. A cage will cost you around $3500 for anything decent is what I hear these days.

[spyderballer]

Ah fair enough. Does your one, as it is allow you entry into any extra events that you couldn't go in without a cage?

[Grrrrrrr!]

Yes, its a MSNZ homologated cage, so any race series like ss2000, rally events (all of them?) that require a cage I could enter. Not that I have the budget for that level of event. I also can take passengers on track etc which you cannot do without a cage at most tracks/trackdays.

[Grrrrrrr!]

So after much time of little progress I finally got around to doing something postive this weekend.

So far i have stripped a gen3 NA head of all the useful bits (the entire valvetrain basically).
I've also pulled the head off the gen2 motor and stripped that down so I can pull the pistons out of the block and measure everything up with my new micrometers and telescopic bore guages to make sure the clearances are okay, and to check for out of round after I put ARP rod bolts into the the rods so I can determine whether I need to get the big ends resized.

Some pics.

Gen3 NA intake valve (left) vs gen 2 turbo Intake valve (right)
Gen3 is necked down behind the head, so might give a little more flow. Can never be sure without a flowbench, sometimes the opposite happens. Going to run the gen 3 valves I think


Gen 2 Turbo Exhaust valve (left) vs gen 3 NA exhaust (right)
Not sure there is any difference between the two, they weigh the same and i've already lapped the gen2 ones so they can go back in.


Gen3 NA intake cam in gen 2 turbo head.. almost no clearance with 9.8mm of lift compared to the 8.2mm of the gen2 turbo cam. Feeler gauges put it under 0.5mm, but more than 0.3mm so i'm good to go without having to file/grind the head for clearance.


Gen2 turbo Combustion chamber, untouched at this stage except for having the face machine flat. Might just take the points off the machined edges to help eliminate hotspots.


Gen3 NA head. This thing is a mess, the valve seat machining is horrendous, big edge transistions everywhere, for example the top right side of the valve in the top left..


Gen2 bucket, retainer, shim and keepers


Gen3 equivalent. 10% lighter, not as much of a difference as i hoped. 1zz shimless bucket will knock about 25% off the weight of the gen2 setup.

[JasonFriday13]

Gen3 NA intake valve (left) vs gen 2 turbo Intake valve (right)
Gen3 is necked down behind the head, so might give a little more flow. Can never be sure without a flowbench, sometimes the opposite happens. Going to run the gen 3 valves I think

I just dug out pictures of my turbo engine, the intake valves have the same step on my engine. Looks like the valves are the same between NA and turbo.

[Grrrrrrr!]

so did some more playing round today.. discovered a few things. Gen3 rods wont fit into gen4 pistons, you either need to machine the top of the gen3 rod to make it narrower, or machine the inside of the gen4 piston to make it wider. Neither option sounds good to me, so not going to do either.


Left to right: gen2 rod & piston, gen3 rod, gen 4 rod.



Conclusion.. gen4 rods are piss weak and only good for throwing at people you dont like...And probably okay for the NA BEAMS engines.. maybe.

[Benckj]

I'm even surprised at the small differences between gen 2 and 3 rods. Did you happen to weigh each of them as well?

[Grrrrrrr!]

No, I don't have scales for that sort of weight, the small ones only go up to 100g, and the only other scales I have at home are bathroom scales that go up in 0.5kg steps.

[Wayne]

gen 2 is just over 750 grams a rod

[Benckj]

gen 2 is just over 750 grams a rod

Any idea how that compares to the gen 3 rods?

[Grrrrrrr!]

I ended up weighing those parts out at the FSAE workshop one night a while back

Gen4 rods, with bolts & bearing shells are 690g
Gen3 rods, 780g
Didn't weigh a gen2 rod, but can't see how its lighter than a gen 3 rod looking at them, so the two scales must disagree a bit.

All the standard pistons are about 530g +/- 5g

Anyway, Wayne dropped by today so I pawned some old junk off on him so the garage floor is not quite as chocka with crap. He's sorting out the water outlet on the head of the gen4 motor for me and giving me some abs front hubs so I can get a wheelspeed signal to the Link ecu for traction/launch control. I need to sort either a reluctor -> square wave interface for the front ABS sensor to get a front wheel speed signal to the Link, or replacing the VR sensor with something that gives a nice square wave output.

I've also done a shit-ton of work in looking at the wiring I need to get the Link hooked up with all the sensors I want. Still need to finish planning the loom and order the bits, but at least now I think I have a source for all the connectors i'm going to use. I hate cutting and splicing old plugs into looms, they are just not reliable or nice to work with, so i'll be spending what is probably going to add up to a couple of hundred on connectors, mil-spec wire and heatshrink/loom sheath.

[Grrrrrrr!]

Progress has been made, have an almost complete shortblock on the workbench at work, just waiting on a couple of o-rings and a water pump to show up tomorrow morning.
Also have the head waiting to be cleaned after lapping the valves in then its time to install new valve stem seals and shim the valves, then set the cams up. Could have a basically complete longblock by monday.

Next challenge is deciding what clutch to run, Not sure whats in the car, but the previous owner told me it was something upgraded. Might have to wait till I drop the other motor and see how much life it has left in it, and get the pressure plate tested for clamp force to see what sort of HP its good for.

Also, if you buy a nzgaskets/permaseal gasket set for the bottom end of a gen3 motor, be aware its actually a gen2 bottom end set and is missing some gen3 bits, like the two orings between the oil pump and the oil pan. Still worth buying since you get all the seals (front main, rear main, oil pump) for less than the cost of a rear main seal from toyota (even with discount). Just be prepared to order a few extra bits to make it complete.

[spyderballer]

Are you going to the toyota track day?

[Grrrrrrr!]

I haven't entered yet, been to busy working on motor and planning loom to do anything about it. I probably should.