Thread: My 396 with Nitrous???

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I have had my Chevy for a while.I don't race the car and just like to drive it on special occasions. The engine is a 396 bored to a 402CI.It has forged pistons,crank,rods.The heads are stock ported oval ports with 2.19 and 1.88 valves.Not sure what the compression is but it has never overheated.OK,when i used my Top Gun Nitrous system for the first time about 8 years ago i shifted into 3rd gear and hit the button.I was blown away from that blast of a drive through 4th through my Muncie M-20,I was amazed at the power!!!I had a Holley strip dominator on it then.Now I have an Edelbrock Torker 2 on for better throttle response.I have a slightly bigger cam now(574-588 now> 595-595 lift) and the bigger valves.The strange thing about it was the car was running terrible with the 650 Holley double pumper carb on it.When i put new plugs in it they would foul out seconds after starting the engine up.The cure was getting my 650 rebuilt by TCI or some company with a T in Texas I believe.It flows 785 rather then the 650.It has a 4 corner idling system.My plugs after years finally were not fouling out but when I used the Nitrous it was nothing compared to when I used the untouched 650 Holley!!!.I use a 150 shot of Nitrous.I use 94 octane gas.I am running about 16 degrees at idle and my question is should i back off the timing by 6 degree's???s

Lets just say the power does not even come close to the old rough running Holley!!!!

Was the cam checked with a degree wheel. It could re retarded slightly, that would explain the drop in power? I would back the timing down to 10-12 degree's. It also sound's like that holley might be screwed up . Has someone else check it out.

Originally posted by 327,JET
Was the cam checked with a degree wheel. It could re retarded slightly, that would explain the drop in power? I would back the timing down to 10-12 degree's. It also sound's like that holley might be screwed up . Has someone else check it out.

Yes the guy who built my engine said that he had to retard the Cam for some reason.I always thought when a Cam is retarded that it gives more top end power.When tuned the car does run well but I have never backed ii down to 10-12 degrees for the Nitrous yet.Im using only 94 octane.Maybe the whole problem is the 16 degree's at idle i was running with the Nitrous??? The carb is still the Holley 650 rebuilt from TCI in Texas or TRC but flows now 785??? I have had the car sitting along time with that carb maybe 10 years or close to it.The guy who built the motor knows how to build engines too.I have had no problems with the engine yet.The only thing is I have yet to drive it with the Torker 2 Intake manifold i put on.This is a very occasional street car.

It also could be when you went with a bigger cam , It might have too much duration for your present compression ratio .That would explain why your power dropped off, you may have picked up top end H.P. but you lost your torque which is what you would feel most.The torker 2 is a good intake but I still think your running a little heavy on cam . good luck.

The cam is ok and when I had the car tuned right it was real fast.I remember when i had a 500 lift cam,that had great low end torque but thats not what i want especially with the Nitrous set up I have now. I just have not driven it for a long time and I drove it once with the Torker 2 Intake and I felt alot more low to mid RPM torque.The cam makes power from 2500 to 6500 RPM's which is reasonable on a street strip car.The car always starts for me.But today I go to start it and it would not fire up.It may be out of gas because the Electrical fuel pump sounds really wierd or just a fuel filter.I know one thing Im tired of buying Spark Plug wires that get burned by the headers.I have to get a new set.I always go with the Moroso's.Its a pain in the ass.

If the headers are burning your plug wires they do make shields which will help prevent this problem, my engine has a set of them.

Originally posted by 29Street-Rod
If the headers are burning your plug wires they do make shields which will help prevent this problem, my engine has a set of them.

Thanks for that advice.I never thought that they would work or they were available.What are the best plug wires to use on a Big Block street strip car with headers??? I always buy the Moroso's and there so dam close to the header its almost impossible that they don't get burned without the heat shields.