Problem. When I get down on it from a stop I get some spark knock and when I'm going over 85 (my speedo only goes to 85mph) I get some knocking there too. I retarded my timing and that took care of it but my car is harder to start and idles real rough at 600-700 RPM.
Can I buy a knock sensor and make it work with this motor? It's a 1979 block out of a truck. If I can, what do I need and how do I do it?

Thanks,

Brad...


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1986 RS Camaro
Mods: Threw 2.8 in garbage, put in rebuilt
350 .060 over, XE268H Comp cam, Edlebrock
Performer Intake and Edlebrock 600 CFM Carb,
Pete Jackson noisy GearDrive (which sounded
cool for about 5 minutes, now I'm sick of it)
Rebuilt TH350, 3.42 slippage in the rear.
Killer Power, OH YEAH!!!!
Gonna blow up that V6 rear real soon

 

i believe the knock sensers are differant for each engine. buy one for a 350 camaro and see if it helps. going to higher octane will help as will timing adjustments. maybe moving around on spark plug heat range will help also.

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ICON Motorsports
1st & 3rd

 

When I buy the knock sensor, where does it go? And is there anything I should know about installing it? I am using high octane gas (92)I'm using Autolite 145 plugs right now. Can you recomend a hotter plug? And I will pick some up today.

Thanks.

 

i'd go with 1 or 2 heat ranges colder on the plugs. the senser screws into the block where the drain plug is, just above the oil pan rail and about mid way between the front and rear of the block. all are on the right side as far as i know, but could be on either side.

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ICON Motorsports
1st & 3rd

 

You can't just screw a factory-type knock sensor into the drain hole and have it work. The factory used the ECM to control spark timing, and a module in the distributor for the knock sensor. You don't have either with your non-CC setup.

You need a complete add-on knock sensor setup, and I haven't seen or looked for one in a long time. Can we assume you don't have EGR? That could be the reason for your problem, and would be easily fixed by recurving your distributor (including both mechanical and vacuum advance). You didn't say what your compression is, but from the rest of your combo it doesn't sound like it would be high enough to cause a problem. No EGR when using an EGR-curved distributor could, however.

By the way, your V6 rear is the same as a 3.42 V8 rear. If it's about to blow, it's not because it came from the factory in a V6 car.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

Well it seems to not knock with the timing retarded, and I think the compression is 9.25:1 The rear is a 3.42, I just figured it wouldn't last long with the extra power of the V8. I have a 1981 Firebird with a 10 bolt posi I could put in it if it does blow. Would be a PITA to do though. How much punishment can the 3.42 rear take? It had 138,000 miles on it with the V6. I'm thinking about adding the Amsoil lube to it, hoping that will prolong the life of it. Gets up and goes pretty good right now, just hope it lasts.

 

9.25 compression shouldn't be causing problems with 92 octane gas. How much did you retard the timing? Do you have the vacuum advance hooked to ported vacuum or full manifold vacuum? Do you know how much mechanical advance you have, and how quickly it comes in? You should know the answer to these questions to fully diagnose your cause.

The AMSOIL gear lube will help your rear last. See the tech articles for a good summary of how to beef up a 10-bolt. Your '81 10-bolt won't bolt into a third gen car, and the guts won't fit.

 

I'm not sure how much the timing is retarded. I have no timing light or the timing mark indicator on the timing cover. My friend said I wouldn't need that cause of the cam I have, he said it would be off. The vacuum advance is hooked up to one of the little vacuum ports on my EB 600 1406 carb. The right port. There is 2 on the front of it.
I have no idea how much mechanical advance I have. Don't know how to tell or how quickly it comes in. I was just out driving it and got down on it from a stop, the motor about died, bogged real bad. Wonder why? Here are the specs for my cam if this will help any.
COMPETITION CAMS CAMSHAFT SPECIFICATION SHEET
Part #12-242-2
GRIND NUMBER: CS XE268H-10
ENGINE CHEV SML BLK 265-400
INTAKE EXHAUST
VALVE ADJUSTMENT HYD HYD
GROSS VALVE LIFT .477 .480
.006 TAPPET LIFT 268 280
VALVE TIMING OPEN CLOSE
AT .006 INT 28 BTDC 60 ABDC
EXH 74 BBDC 26 ATDC
THESE SPECS ARE FOR CAM INSTALLED
AT 106 INTAKE CENTER LINE
INTAKE EXHAUST
DURATION AT .050 224 230
LOBE LIFT .3180 .3200
LOBE SEPARATION 110
THIS CAM SHOULD USE SPRING # 981-16




------------------
1986 RS Camaro
Mods: Threw 2.8 in garbage, put in rebuilt
350 .060 over, XE268H Comp cam, Edlebrock
Performer Intake and Edlebrock 600 CFM Carb,
Pete Jackson noisy GearDrive (which sounded
cool for about 5 minutes, now I'm sick of it)
Rebuilt TH350, 3.42 slippage in the rear.
Killer Power, OH YEAH!!!!
Gonna blow up that V6 rear real soon

 

You need to get the proper timing tab installed. The cam does not affect how the mark works, although it can affect how your timing should be dialed in (due to reduced vacuum, especially at idle). I say "proper timing tab" because some engines have the tab at 12 o'clock relative to the harmonic balancer, and some more like 1 o'clock. The balancer is actually what determines which one you need.

You probably have a gob too much advance right now. Setting the timing based on the idle will always give you too much advance. After you get a timing tab and timing light, set the initial advance at 8-10 degrees and the total mechanical (w/o vacuum hooked up) at 34-36 degrees - you determine the total advance either with timing tape on the balancer, an "advance"-type timing light, or by a distributor machine. After the timing is correct, tune the bog and idle problems out of the carb.

I'm not familiar enough with Edelbrock carbs to know whether you're hooked to ported or manifold vacuum, but it should be ported (no vacuum signal at idle).