#41
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How old r the plugs
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#42
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brand new Frank, just dyno and run time since I had engine in car.
Ill try my 750 Carb if there is no Big change then Ill look into ignition and wiring. I could have broke a ground etc. while installing the Engine.
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"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen US NAVY RETIRED |
#43
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run on after ignition kill is detonation. especially on a carbed car. you have something wrong on one or multiple cylinders. i suspect lean in forward and read cylinders. being a carb intake. middle cylinders fueled well outside ones not so much, especially at low engine rpm/vacuum. use a heat gun to see your exhaust temps. like i sed before. will tell you what cylinders are hot and to look at intake gasket in that area possibly.
what dynamic compression is this motor. i dont care what paper sez for 12:1 blah blah. what is the cold cylinder pressure in PSI. first hit and max psi. as far as cold start sounds like timing. you run a choke? does it fully close? try not closing it completely. big cams are very inefficient at low rpm/idle. not a lot of fuel needed to get it started and keep it going.
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1998 Firebird:buncha parts thats used to make it go fast..... not so much anymore. BAAAAAA!!!!!! |
#44
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no choke pizza.
__________________
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen US NAVY RETIRED |
#45
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After run means not enough octane fuel imho
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2000 SS Procharger 98 Z vert turbo 07 TB SS cai catback and tune |
#46
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Throw some race gas in it. A big cube small block like that I bet is 14:1 or more
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2000 SS Procharger 98 Z vert turbo 07 TB SS cai catback and tune |
#47
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11:1 compression recommended fuel is nothing less than 93 octane.
I just put 5 gallons of 114 in it today after trying out the smaller Carb. Seems to run much better and seems to idle better too. Ill wait till morning and do a cold start to be sure. gonna use temp gun on it aswell.
__________________
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen US NAVY RETIRED |
#48
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i dont think what John is saying is the correct way to say it. but what he means is, 14:1 dynamic compression. "11:1" doesnt mean anything other then the measurements of the components installed. Now how alll those components interact is another story. meaning is the cam big enough to bleed off the added cylinder pressure created from the bore increase alone. so 11:1 would be around 200-225 psi. my car as an example was supposed to be only 11.8:1. I had over 280PSI in each COLD cylinder. 93 octane is JUST about enough to keep the heat out of the motor. With some funky timing tables and cold start tuning it starts and runs. but with out EFI it have to run 100+ octane. Or a new cam. so measure compression. that might be why engine builder sez a MEASLY 12* timing at idle.
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1998 Firebird:buncha parts thats used to make it go fast..... not so much anymore. BAAAAAA!!!!!! |
#49
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well to be fair he did say 32 to 34 degrees at 3400 rpm and at idle the initial will fall where it may.
I saw 12 degrees at idle after setting total at 32 degrees. but I think with smaller Carb it runs much better.
__________________
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen US NAVY RETIRED |
#50
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header temps were 225 to 260, the outer were cooler than the 4 inner cylinders. But she starts right up and no popping or run on so I think its allmost right where it needs to be. also no more gas smell at idle.
__________________
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen US NAVY RETIRED |
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