Distributor installation

Just finished rebuilding a small block chevy in our '86 iroc camaro. I think I installed the distributor correctly, but is it possible I installed it 180 dgrees off? It's been many years since I've done this and while I managed to get the engine to sort of run, it's back firing like crazy-a lot of flames shooting out from the headers, and I have to keep pumping the gas pedal and then shuts down. I smell gas in the oil, which tells me I'm not getting full combustion. I forget...Does the crank turn two revolutions to complete one 4 stroke cycle? I'm thinking that perhaps I installed the distributor TDC while in the wrong stroke.

It's pretty easy to install it 180 out. Remove and replace it and try again.

I did the same thing on a 327 in my chevelle........I simply moved number
one wire 180 and went from there..car runs perfect...rdobbs

If this thread is dormant since June maybe I can ask a question. Sadly my new HEI distributor will not clear the firewall in my Bebops 'glass '29 body! The latest strategy is to put in a stock "reman" points distributor (SBC 350) which is cheap for only about $37 at Advanced Auto and has a 4" diameter base rather than the 5" diameter HEI base which "almost" clears. Then I can add a "kit" from Summit to put in an infrared optical pointless breaker system that is suposed to be accurate to 10,000 rpm with a Accel coil that is supposed to be good up to 6500 rpm, that is good enough for me! I will use the Accel kit instead of the Mallory kit because the matching Accel coil is a little cheaper and I will be pleased if the ignition system is reliable to 6000 rpm. Any comments or experience with this type of kit to replace the breaker points in a stock distributor? Any comments DennyW?

Don Shillady
Retired Scientist/teen rodder

I would replace it with a Petronix system. I haven't had very good luck with Accel anything, but I've had good results with Petronix.

NTFDAY, Thanks for the tip! Just for the record, at Advanced Auto the SBC points distributors are starting to get rare, so the search for the part is a bit like the old restorer game!

Don Shillady
Retired Scientist/teen rodder

If you can't find one I'll look around and see if I find a rebuildable one in all of my junk in the garage. If I have one you can have it for the shipping.

NTFDAY, Thanks for the offer, I will keep it in mind. I am supposed to pick up one from Advanced tomorrow morning, but this is the second try. The first try produced a "remanufactured" unit which had one ear with the centrifigal weight bent at about a 30 degree angle! When "we" searched the Advanced Auto network, most stores in Virginia had zero units of that type but one store in Roanoke Va had 13 units, so if I just keep reordering one until I get a good one I should be OK but it is interesting that what was once the "Heartbeat of America" is starting to look like a restorers quest now! The Petronix unit is just slightly more expensive than the Accel unit but the Petronix unit is rated to an amazing 15,000 rpm so it must be a pretty good unit worth the extra $10. Just for discussion on this thread a smaller unit for about $185 from Mallory has dual points and has a base of only 3 5/8" diameter and sure to fit my firewall, but other sources have warned that the dual points have weak springs which will allow point float at a relatively low rpm. So the idea of a magnetic points units for a lower total price seems like a good idea and the Petronix unit seems like the best of the several available units, thanks for the tip.

Don Shillady
Retired Scientist/teen rodder

I have a Mallory dual point in the Mustang and I changed it out for a Petronix unit as the continual adjustment of the points became too much of a hassle. I opted for their matching coil and I did the same when I changed to a Petronix unit in the 73 F100. FWIW, the Petronix unit can wreak havoc on certain tachs, but as I recall there is a unit available to cure the problem.

...ahhhhhh one of the JOYS of a FORD engine - with no dist to firewall clearance problems!!! (yeah the pan.....)

Don, another to consider tho a bit expensive(tho consider how many other $$$ you have invested) is the MSD small diameter, ready to run version

http://www.msdignition.com/Products/...stributor.aspx

OR

Small diameter version
http://www.msdignition.com/Products/...stributor.aspx

I was gonna say the same thing IC2 said: aftermarket small housing; all of the majors make them.

IC2 and Rrumbler, I did spend some phone time with a tech guy at Mallory and the Tech guys at both Speedway and Summit. Unfortunately I would have had to invest about $200 more for a small diameter distributor for which I would not know if it fit unless I bought it and if it did not I would then have the return-policy hassle, soooo the best suggestion was from my wiring guru "Rick" who is the patient hand-holding tech guy at "It's a Snap" (1-866-462-7628 toll free) who advised to buy a low priced "Reman" Chevy points distributor and if it fits my firewall I could then upgrade it with something like the Petronix kit NTFDAY advised. Rick has a Petronix type unit on his '71 Corvette and he warned that the Mallory dual point 3 5/8" diameter would suffer from point-float and would still need frequent adjustment. At $47 (including paying the $5 core charge for the unit I did not have and adding a new cap) Advanced Auto was by far the cheapest deal in my area out of five different stores. Others wanted about $65 with an added $15 core charge and I still would not know if it fit until I tried it! Well the Advanced Auto deal was the cheapest because the first unit I got was bent really bad and you could not even put the rotor cap on it so I had to wait two more days for a replacement. This morning I stopped in to Advanced Auto on the way home from church (they are open on Sunday) and it was there. A quick change of clothes and a trip to the garage produced the satisfaction of a "drop-in" for the points distributor once I took off the rotor cap and wiggled the base so that the narrow part of the base passed the ledge in the firewall. Just for the record there is PLENTY of room in the Bebops firewall toward the rear indentation and there is plenty of room above the cap for the plug and coil wires after the unit is in the block BUT (!) the overhanging edge of the firewall is about 1/4" too short in the vertical dimension and the base of the HEI distributor forces the shaft forward and the angle will not let the shaft go down the hole vertically! Since I need to prelube the oiling before starting the engine I need an easy way to prime the oil pump right before starting and then install the distributor shortly thereafter, so the alternative of unbolting the trans mount at the rear of the trans and gaining the 1/4" by dropping the trans down a little seemed to be too much work to be practical at the time of the first startup. Now back to the original topic of this thread, the mysterious 180 out-of-phase condition. I had to take off the rotor cap to get the flat part of the advance weights parallel to the firewall and that means I will have to remove the rotor cap to take the unit in or out and that leaves the possibility to remount the two screws of the rotor cap 180 degrees off relative to the offset oil pump key at the bottom of the shaft. I made a small mark with a blue felt tip pen on the advance weight plate to keep the orientation of the rotor as original relative to the position of the shaft key at the bottom of the unit. Maybe that is a source of occasional need to offset the wires by 180 after reinstallation of the distributor. Anyway, I now look forward to installing a Petronix kit with a coil good to 6500 rpm. It was interesting to me to learn that the ballast resistor with a given coil needs to be matched to the desired rpm maximum which I should have realized from studying (and soldering lab circuits) that there is a L-R time constant in an inductor coil circuit. A slightly larger resistor allows the spark to last longer but limits the maximum rpm. For me 6500 rpm seems like a reasonable maximum for street, noting that the Petronix magnetic switch unit can go up to 10,000 rpm, so it is the combination of the coil inductance and the ballast resistor that determins the maximum rpm. Anyway I can probably resell the HEI unit on the local Trading Post and use the small base (4") distributor with the Petronix unit. Thanks NTFDAY for useful information!

Don Shillady
Retired Scientist/teen rodder

Don FWIW, if your tach is an old style like my Sun there is a possibilty the Pertronix will cause it to read low. A variable capacitor or resistor would allow you to adjust the C-R time constant which is what the Sun tach uses as a triggering device.

NTFDAY,

Thanks for the warning. I planned on checking with the tech guy (Rick) at "It's A Snap" where I got my tach. There seems to be two levels of Petronix kits and I hoped to use the less expensive model but I will check with "Rick" aqbout the tach.

Don Shillady
Retired Scientist/teen rodder

Quote:

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Originally Posted by Don Shillady

NTFDAY,

Thanks for the warning. I planned on checking with the tech guy (Rick) at "It's A Snap" where I got my tach. There seems to be two levels of Petronix kits and I hoped to use the less expensive model but I will check with "Rick" aqbout the tach.

Don Shillady
Retired Scientist/teen rodder

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I believe there are three levels and IMHO the first level is quite adequate for your engine which I doubt will hardly ever, if ever will see more than 5000 rpm.

NTFDAY,
That is probably right, but I commute frequently to a place where the on ramp to I-95 is unusually short under a bridge and to get into the right lane I routinely have to wind up my little Sunfire to about 4500 and sometimes higher. With the low first gear in my R700 in the '29 I might occasionally get past 5000, but you are correct that 6500 is past where I probably ever will go with my very mild cam. I will leave the 8000 rpm coil to Mark Martin who needs the extra rpm! Probably those NASCAR rides turn 9000 or more at times but 6500 does seem ridiculous to me unless I rev the engine in the garage just to see how high the tach will go and it is limited to 8000 anyway. So this is just chit chat but I was really pleased that after a fair amount of frustration I got a distributor which finally went into the hole!

Don Shillady
Retired Scientist/teen rodder

I don't think that you'll have to get much past 3500 with the 29 to be able to merge into traffic with little effort. It's great that you were finally able to find a distributor that suited your needs. I look forward to the day you finally get the 29 on the road.

NTFDAY,
Just a quick reply. "Rick" at Its-a-Snap says he knows of no problem with their tach (which I have) and the Petronix kit but he recommends a Delco coil. Today on the way home I had the usual tricky business merging into I-95 at that spot in Richmond with a very short on-ramp and today my Sunfire went briefly to 6200 rpm in low gear before it shifted so I think I need to keep the 6500 rpm range in mind for the '29. It is surprising to me there are not accidents at that site because if you do not make it into the right lane I-95 goes under an overpass of U.S. Route 1/301 with no room on the shoulder under the bridge. You have to merge somehow or else be squashed into the side of the bridge piers. In the past I took no notice of the tach, but it is surprising the little Sunfire revs so high and the red zone is at 6500 rpm. The little 2.2 L Sunfire 4-cyl is by no means a "quick car" but apparently the first gear is low enough to allow high revs if you need it. Of course it is getting annoying to not have the '29 on the road yet but having a distributor makes it seem closer to that day with an easy way to pre-lube the engine before the first startup. I have invested in Joe Gibbs break in oil but I will still need to pull the distributor to pre-lube it just before startup.

Don Shillady
Retired Scientist/teen rodder

Well the Petronix kit arrived yesterday along with some wiring looms and today I messed with the installation. There is always some fly in the ointment so today I went through the installation steps and found that my centrifugal weight plate is not quite flat (it is "remanufactured" not new) so that the Petronix magnet ring runs up and down more than the 0.060" tolerance so I shimmed the bottom of the shaft with the washer that came for that purpose and I "hope" I reinstalled the gear pin without rotating the gear 180 degrees and I will have to mess with the little shim washers between the magnetic ring and the rotor cap. The instructions say to use the same number of shim washers on each side of the rotor cap but that would not help me because the plate holding the rotor is not level so I guess I will mess with shimming just one side. I am writing this to correct a comment I made above about the interchangeabiliy of the rotor cap screws. Upon close examination the cap has one round pin and a square pin on the other underside of the rotor so you can really only install the rotor one way, but now I have to worry if I reinstalled the gear 180 off? Anyway I am creeping forward somehow. I also purchased the Flamethrower coil recommended by Petronix in the hope of matching the correct coil as specified in the kit, we shall see how it works!

Don Shillady
Retired Scientist/teen rodder

If you're 180* out it will try to fire but will backfire through the carb, not good. Just bring #1 to TDC and check the position of the rotor in reference to #1 cylinder and go from there. Also, do not use a cheap rotor and cap as they have poor dialectic strength and will cross fire in a short period of time.

NTFDAY, Thanks for the further hint. I now have the stock rotor cap so I wonder where to get a performance rotor which will handle the 40,000 volts of the Flamethrower coil. Gee I bought the Flamethrower coil so that it would be compatible with the Pertronix kit. Today I discovered a small set of mini feeler gauge blades with a hole in one end that I can clip off and make whatever thickness shim wasers I need to keep the magnetic rotor nearly level. The small washers that come with the kit are supposed to be 0.032" thick but they are too thick for my situation. Using the end of the small feeler gauge blades with the hole I can make shim washers of known thickness and at $4.75 for the set that is a cheap way to get precision in the shims. I chatted briefly with the Tech guy at Pertronix and he said the rotor will work in the range of 0.010" to 0.070" but with the feeler gauge blade tips used as shim washers I should be able to get it spaced out to 0.030" all the way around the ring. He also said the warranty on the Pertronix kit will be voided if the ring touches the ignitor receiver so the 0.010" clearance is the absolute minimum. I thought maybe the path through the magnetic fields determined the dwell time of the spark but he said it is only a trigger and the kit should work out to a gap of 0.070". As usual this is turning out to be more complicated that if I had just bought a new distributor and I now know the points-type base can go into my block past the firewall but I now have almost as much money in the distributor as a new one but I will keep on trying to get it right. If I get a backfire through the carb I will certainly scrap this troublesome dizzy and just get a new one!

Don Shillady
Retired Scientist/teen rodder

If memory serves me right there is an adjustment when the unit is installed. DO NOT set it with steel feeler gauges, instead use brass as they are non magnetic. Pretonix, if still the same, is based on a hall effect transistor circuit and steel gauges could damage the circuitry.
Most auto parts stores carry a cheap cap and rotor set as well as a heavy duty set or you could go to Summit and order one from them.

I bet that MSD Ready To Run dist looks good now

(sorry - I JUST had to say it:CRY::CRY:)

IC2, I had to creep up on the price since I did not know if the point-distributor base would fit; NOW I know it will (just barely!). Just for the record I will have to disassemble the kit since the only way the distributer will get around the edge-lip of the firewall at the top is if the rotor cap is off and that means I will probably have to remove the magnet ring when I put it in the motor but I know how to do that now! Going the other way I could have wasted more money on the smallest 3 5/8" diameter Mallory dual point setup and then had a rpm limit; still it is good to hear from you, the next time you visit Midlothian please stop in and help with a wire or two. Since I am working mornings to pay for the anticipated top and upholstery I am wiring at a rate of about 1 wire/month! I have spent at least two weeks messing with this distributor thing. Anyway, I have a lot of good suggestions from NTFDAY and today I found some small brass washers at Home Depot (after trying three electrical suppliers in the nearby Hanover Air Park Industrial site!) and put two No. 8 brass washers under the rotor bolts and a single small No. 6 brass washer under the bottom of one of the cap bolts. Now I have a fairly smooth path with a gap of about 0.035+/-0.005" all around within the tolerance of 0.010"-0.060". The washer for the bottom of the shaft took most of the slack out of the worn thrust bushing at the bottom of the gear. Assuming (?) I got the gear back on the correct way I am pretty pleased with the result. I had to remove the pin through the gear to add the new thrust washer and I think it goes through the center of the shaft with no offset????? Thanks NTFDAY! I have been to conferences where the Hall Effect was the subject of discussion but I was fooled by the steel color of the washers that came with the kit, maybe they are aluminum because they scratch silvery; anyway they were too thick and now I have thin brass washers which are better.

Don Shillady
Retired Scientist/teen rodder