rmag

I've got a '96 993 race car and blew the motor at Sebring last weekend. Going to have my shop backdate the car to a '95. If there are any DIY'ers out there that want to swap their non varioram intake/ecu/harness for my varioram intake/ecu/harness, it's available, otherwise just going to purchase the parts. (Gratis picture of car and blown case )

race911

Sorry to see. Know exactly what happened yet?

rmag

Lots of carnage inside, but best shop can tell the #1 rod snapped first, then took out case, cylinder and head. Rod bolt broken also, but even with that rod was still connected to the crank so they think that was effect, not cause.

bobt993

Ryan,

You likely dropped a valve and the piston met it in the cylinder. I have a complete plastic intake for a 95 if you need it. The weakest link is the keepers.

NP993

Ryan -- if I'm not mistaken, you don't even need to swap harnesses. A guy on the list put v-ram on his '95 and didn't have to. Hopefully he'll chime in, he's the expert in this procedure.

bobt993

Back dating a Vram is actually very simple since you are deleting the tuning runners and only using the resonance flap. I believe there are some engine harness differences at the sidewall plug in. Check with someone with a 95. I do think there are other changes required to meet PCA scruit and the heads on a 96-98 have slightly larger intake valves. It is common to use the plastic intake to drop the added weight on the motor. You lose low end torque, but if your shorter geared the engine will always be in the higher rpms where the added torque benefits are not available.

rmag

Yep I saw that thread. I want a '95 ECU because it is programmable (I'm running prepared class), while the '96 isn't. I figured if someone wanted the varioram, they could take the ECU and harness so would work perfect in their car, while giving me the bonus of being able to program/tune the new motor.

rmag

Exactly. Also the ecu for 95 is 55pin vs 88pin for 96-98(non euro), hence need to swap harness also. I emailed Walt and he's good with it as long as I have the 49mm intake valves also. I have the 4.0 R&P so low end torque less of an issue as you said.

geolab

wait,,,, downgrading to smaller valves as well ? with 4.0 liters ?
more info would be swell.

mongrelcat

Wow!

bobt993

If you read this again you will notice 4.0 R&P (ring and pinion). The 8/32 R&P tightens up the shift band.

geolab

ooops, final drive ratio, got it thanks
I am still curious about the valve sizes.
exhaust and intake, new heads or rework ?
subscribed

Mark in Baltimore

I thought Todd paid A LOT of money for a 4.2 liter motor??

rmag

I'm no mechanic, just kinda regurgitating what my shop says and what I've picked up reading about all this stuff. But yes, new case, heads, and at least one cylinder/piston. From what I gather, the shop is bascially going to salvage what few pieces if any are still good from this motor. The good news they said was when the rod let go it immediately took out some part of the internal oil system, where it stopped the flow and metal didn't have a chance to get throughout the motor and oil coolers. But tear down isn't complete, so will know more on that soon.

rmag

If that was a 4.2 motor, all us 993 Stock class 993s are in trouble! I knew when I got the car, motor has a rebuild in its future. I was hoping to get one season out of it, not one race Watch the first 3 laps of qualifying here. The 2 964s I catch on the back straight first lap are both G cars, and they pull me by probably 8-10 car lengths! (That's why I'm not to upset about having to rebuild)