Building 911 Race Engine, 3.4L (from a 3.6) - options?
08-27-2002, 09:55 PM
#1
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Join Date: Aug 2002
Location: Los Gatos, CA
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Building 911 Race Engine, 3.4L (from a 3.6) - options?
Application: 911 Race Engine rebuild, 3.4L (objective is PCA GT3R race class)
budget: $12,000 (Total)
Starting with:
-1996 993 Engine, 3.6L basically stock motor
-Bought it with 485 miles on it
-Installed Jerry Woods Valve Spring kit, raceware rod bolts.
- converted to solid rockers from stock hydrolic
- updated cam oil spray bars
-motor currently has approx 200 hours on it, and a few overrevs up to about 8000 due to missed shifts so I'm obviously due for a rebuild.
exhaust: headers + phase 9's.
Injection: '92 964 C2 Cup injection w/ Motronic DME, rev limit set at 7500
"The Program" DME piggyback computer system
This injection setup was chosen due to the fact that I had no brain w/ the engine and the VarioRam needed at least a 1996 brain which I could not locate at the time we installed the motor. The system works amazingly well. Jerry Woods installed it, tuned it, and the engine dyno'd at 292hp. I also still have the original VarioRam system which, as it turns out, I could have used with the piggyback unit although the jury is still out on what the benefits would have been had we used that.
Objective is to not go crazy with the rebuild and keept total costs in the $10-12K. Some assumptions I'm making:
- lower the total displacement to 3.4L, increase the hp
- have a solid, reliable at least 50 hour (1 season) motor
- would like better low-end torque (ie, lower rpm limit)
- I'll be dismantling the motor (as I did previously) and having various machining jobs farmed out as needed.
- if possible, keep the current injection system. HOWEVER, not sure about the limitations that places on my choice of a decent cam. Significant I suspect.
Lowering the displacement either means new PC's or sleeving the current cylinders and reducing the size of the pistons from 100mm to 97mm. If it's new PC's, my first inclination would be to use a 3.0L crank w/ 70.4 x 100mm JE PC's, carillo/pauter rods, new valve springs, flowed heads. doing all that leads me to want a decent cam which points me down the path of a new injection system like 56mm TMWs and an engine mgmt that would serve the purpose like Halltech (sorry, Motec is outside the budget).
so many choices, so little $$!! Any help and advice appreciated in a big way. Oh and any rebuilt 3.4L race motors for sale might even be an option.
Jeff
Bushwacker Racing
<a href="http://www.bushwacker-racing.com" target="_blank">http://www.bushwacker-racing.com</a>
jeffs@bushwacker-racing.com
budget: $12,000 (Total)
Starting with:
-1996 993 Engine, 3.6L basically stock motor
-Bought it with 485 miles on it
-Installed Jerry Woods Valve Spring kit, raceware rod bolts.
- converted to solid rockers from stock hydrolic
- updated cam oil spray bars
-motor currently has approx 200 hours on it, and a few overrevs up to about 8000 due to missed shifts so I'm obviously due for a rebuild.
exhaust: headers + phase 9's.
Injection: '92 964 C2 Cup injection w/ Motronic DME, rev limit set at 7500
"The Program" DME piggyback computer system
This injection setup was chosen due to the fact that I had no brain w/ the engine and the VarioRam needed at least a 1996 brain which I could not locate at the time we installed the motor. The system works amazingly well. Jerry Woods installed it, tuned it, and the engine dyno'd at 292hp. I also still have the original VarioRam system which, as it turns out, I could have used with the piggyback unit although the jury is still out on what the benefits would have been had we used that.
Objective is to not go crazy with the rebuild and keept total costs in the $10-12K. Some assumptions I'm making:
- lower the total displacement to 3.4L, increase the hp
- have a solid, reliable at least 50 hour (1 season) motor
- would like better low-end torque (ie, lower rpm limit)
- I'll be dismantling the motor (as I did previously) and having various machining jobs farmed out as needed.
- if possible, keep the current injection system. HOWEVER, not sure about the limitations that places on my choice of a decent cam. Significant I suspect.
Lowering the displacement either means new PC's or sleeving the current cylinders and reducing the size of the pistons from 100mm to 97mm. If it's new PC's, my first inclination would be to use a 3.0L crank w/ 70.4 x 100mm JE PC's, carillo/pauter rods, new valve springs, flowed heads. doing all that leads me to want a decent cam which points me down the path of a new injection system like 56mm TMWs and an engine mgmt that would serve the purpose like Halltech (sorry, Motec is outside the budget).
so many choices, so little $$!! Any help and advice appreciated in a big way. Oh and any rebuilt 3.4L race motors for sale might even be an option.
Jeff
Bushwacker Racing
<a href="http://www.bushwacker-racing.com" target="_blank">http://www.bushwacker-racing.com</a>
jeffs@bushwacker-racing.com
08-29-2002, 04:55 AM
#2
Instructor
Very cool website - and a very cool car!
Did you see this thread - see the third post down:
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=10&t=000604" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=10&t=000604</a>
Can you sell what you have for $6k?
Did you see this thread - see the third post down:
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=10&t=000604" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=10&t=000604</a>
Can you sell what you have for $6k?
08-30-2002, 09:26 AM
#3
You might want to contact Mike Bavaro at <a href="http://www.bodymotion.com/" target="_blank">Bodymotion</a>, he has been racing a setup similar to what you describe for a few years.
10-01-2002, 08:27 PM
#4
Addict
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My thoughts would be to use a 3.0 crank with custom long rods to put the stock piston back into the correct place at TDC. A mild cam like the Jerry Woods "carb conversion" special will work with your pistons & springs, although I would not change the intake system that you have, the TWM's in my opinion are way too large.
I also suggest that you discard the piggy back and spend the other half of your budget on a motec or similar system instead. You must use larger injectors to get proper sequential injection, you will be wasting your time with the stock injectors. Our STANDARD 3.6 RS engines give 318-324 bhp and 295lbft with Motec and big injectors.
Pay a lot of attention to compression and squish, basically run the pistons as close to the heads as you dare!
To qualify this our last 964RS 3.6 with stock pistons, similar cams, small throttle bodies (42 tapered), motec & headers gave 324 at the wheels.
I can also recommend Mike Bavaro at Bodymotion incidentally.
Good luck
I also suggest that you discard the piggy back and spend the other half of your budget on a motec or similar system instead. You must use larger injectors to get proper sequential injection, you will be wasting your time with the stock injectors. Our STANDARD 3.6 RS engines give 318-324 bhp and 295lbft with Motec and big injectors.
Pay a lot of attention to compression and squish, basically run the pistons as close to the heads as you dare!
To qualify this our last 964RS 3.6 with stock pistons, similar cams, small throttle bodies (42 tapered), motec & headers gave 324 at the wheels.
I can also recommend Mike Bavaro at Bodymotion incidentally.
Good luck
10-03-2002, 10:58 PM
#5
Rennlist Member
Jeff,
I can set you up with a DTA fuel and ignition mgmt system...full seq on both inj an dspark.
See <a href="http://www.dtafast.co.uk" target="_blank">www.dtafast.co.uk</a> for more details
cost complete is $1590 and you build the harness.
email me privately for details..
Marc
DEVEK
I can set you up with a DTA fuel and ignition mgmt system...full seq on both inj an dspark.
See <a href="http://www.dtafast.co.uk" target="_blank">www.dtafast.co.uk</a> for more details
cost complete is $1590 and you build the harness.
email me privately for details..
Marc
DEVEK
