replacing opti spark with HEI dist.
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replacing opti spark with HEI dist.
I'm carbing my 93 c4. I need some imput on mounting some kind of timing mark on or near front cover, I plan on using my stock balancer,7 in. The front cover plug that summit sells with timing mark on only fits 95 to 97. Can someone shed some lite on this ???
Safety Car
Joined: Sep 2010
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From: Indiana PA
I hope you don't intend to keep the factory gauges and other items like the ABS/ASR functional at all.
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Well I used my opti as a template, made a bracket out of 1/8" aluminum and fabed a pointer tab to show timing. Also did a clean up cut on my stock balancer will use 7" timing tape to mark degrees . Used a wire in #1 cyl. to find TDC. I have more work on other areas I'll let you know how it ends up.
Melting Slicks
Joined: Sep 2008
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From: Cherokee National Forest TN
There is dwell time as the piston gets to top dead center.
Using a tool made from a strip of heavy flat stock drilled to bolt to the block across a cylinder & threaded in the center for a bolt to adjust the stop height. The piston is brought up & stopped against the tool adjustment bolt. When stopped the balancer is marked at the pointer. Back the engine up until the piston stops against the tool. Mark the balancer again. TDC is exactly in the center of the two marks on the balancer. Adjust the pointer to correspond to TDC.
Might be able to do it with a bolt screwed into the spark plug hole. Don't know, never tried it, never will.
Spark plug thread size is 14mm x 1.25 pitch.
Good luck
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Melting Slicks
Joined: Aug 2008
Posts: 2,082
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From: Palmdale CA
Close but no cigar. Close might be ok for a street motor
There is dwell time as the piston gets to top dead center.
Using a tool made from a strip of heavy flat stock drilled to bolt to the block across a cylinder & threaded in the center for a bolt to adjust the stop height. The piston is brought up & stopped against the tool adjustment bolt. When stopped the balancer is marked at the pointer. Back the engine up until the piston stops against the tool. Mark the balancer again. TDC is exactly in the center of the two marks on the balancer. Adjust the pointer to correspond to TDC.
Might be able to do it with a bolt screwed into the spark plug hole. Don't know, never tried it, never will.
Spark plug thread size is 14mm x 1.25 pitch.
Good luck
There is dwell time as the piston gets to top dead center.
Using a tool made from a strip of heavy flat stock drilled to bolt to the block across a cylinder & threaded in the center for a bolt to adjust the stop height. The piston is brought up & stopped against the tool adjustment bolt. When stopped the balancer is marked at the pointer. Back the engine up until the piston stops against the tool. Mark the balancer again. TDC is exactly in the center of the two marks on the balancer. Adjust the pointer to correspond to TDC.
Might be able to do it with a bolt screwed into the spark plug hole. Don't know, never tried it, never will.
Spark plug thread size is 14mm x 1.25 pitch.
Good luck
there are several degree's of Crank travel before, and after TDC were the piston does not move.
Le Mans Master
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From: Manassas VA
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I know my method of finding TDC is crude , but it will get dynoed and the timing will be adjusted to max power. probably between 36 to 40 degrees total. That mark will be noted. My proform HEI has no vac advance, mech advance is all in at 2400 with total at 20 degrees. initial timing about 18 degrees. I dont think my methods will keep it from starting .
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I know my method of finding TDC is crude , but it will get dynoed and the timing will be adjusted to max power. probably between 36 to 40 degrees total. That mark will be noted. My proform HEI has no vac advance, mech advance is all in at 2400 with total at 20 degrees. initial timing about 18 degrees. I dont think my methods will keep it from starting .
Melting Slicks
Joined: Sep 2003
Posts: 2,270
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From: N. Babylon NY
Well my carb & hei project is complete. 750 holly dbl pumper & GM gen II LT-1 carb manifold with proform HEI dist. On chassis dyno my 93 made 289 HP at rear wheels with stock torque converter. Before this change over it ran 13.30 & 40 at 102 MPH with stock motor and 4:10 gear. Went to maple grove to test. car bogged real bad, like hit your head on steering wheel. Still it managed a 12.96 at 108 MPH. Replaced stock converter with 10 in 3500. WOW ran 12.373 at 108.96 with 1.687 60 ft.With some more tuning may be 11.90 ???
That moving!!
My 92 makes the same RWHP (289) and went a 13.02 @106 mph (1.89 sixty foot) with 6 speed and stock rear 3.4x gears. In the process of having a 9" rear with 4.11 gears installed. I don't think I will go as fast as you-But I am hoping for 12.8-12.9 As soon as it is completed I will take it to the track.
Regards,
Steve
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You are saying 12.37 with 289 HP, 3500 stall converter, and 4.10 gears? What is the weight of your car?
That moving!!
My 92 makes the same RWHP (289) and went a 13.02 @106 mph (1.89 sixty foot) with 6 speed and stock rear 3.4x gears. In the process of having a 9" rear with 4.11 gears installed. I don't think I will go as fast as you-But I am hoping for 12.8-12.9 As soon as it is completed I will take it to the track.
Regards,
Steve
That moving!!
My 92 makes the same RWHP (289) and went a 13.02 @106 mph (1.89 sixty foot) with 6 speed and stock rear 3.4x gears. In the process of having a 9" rear with 4.11 gears installed. I don't think I will go as fast as you-But I am hoping for 12.8-12.9 As soon as it is completed I will take it to the track.
Regards,
Steve
Melting Slicks
Joined: Sep 2003
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From: N. Babylon NY
car wt. with my fat a-- in it 3425 lbs. 700R trans shifts at 5600 and traps at 5800. tire size is 13.50X28.0 M/T. Rear is 12 bolt w/4-link. No tube headders just cast iron manifolds. maple grove time slip reads 60' 1.687 330' 5.020 1/8 7.857 MPH 86.67 1000' 10.305 ET 12.373 MPH 108.96. With EFI and stock coverter my 60' was 1.860. Steve if you can hook it with 106 MPH you should be mid to high 12's.
For comparison my car will also have a 4 link and 4.11 but with a 315x17 DR which measures about 26" x 12.5
Regards,
Steve
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Hey Steve, the 289 HP is with carb & stock converter. The bolt-in 12 bolt with 4 link is from House of Hook. It's a real nice kit, with some assy required. This kit is not for beginners. On this forum he has gotten bad feed back, I had to tweak a few things for a correct fit. It was not due to bad workmanship but variables in the cars from year to year.Others expect to take it out of the box and it will install itself. It worked exactly like Jesse said it would.
Melting Slicks
Joined: Sep 2003
Posts: 2,270
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From: N. Babylon NY
Hey Steve, the 289 HP is with carb & stock converter. The bolt-in 12 bolt with 4 link is from House of Hook. It's a real nice kit, with some assy required. This kit is not for beginners. On this forum he has gotten bad feed back, I had to tweak a few things for a correct fit. It was not due to bad workmanship but variables in the cars from year to year.Others expect to take it out of the box and it will install itself. It worked exactly like Jesse said it would.
Mine is being installed by a local racecar shop. If we are both making the same power-Maybe mine can go deep into the 12s. I would like to think a stick can go as good as an automatic.
Good luck with it!
Steve