Stovebolt distributor

[Don Coatney]

Darin's car, with the Stovebolt HEI, sure does run nice and smooth.

How is his vacuum advance connected? Manifold or ported?

[Normspeed]

Ported.

[Don Coatney]

Ported.

Does his engine ping at all going up the hills?

[Normspeed]

No ping at all. It does seem to require downshifts to second earlier than mine would, seems like less low end grunt, could be the rear gears. but I have a 4:10, and not sure what's in Darin's. His was a non-OD car, so maybe a 3.73.

[Don Coatney]

No ping at all. It does seem to require downshifts to second earlier than mine would, seems like less low end grunt, could be the rear gears. but I have a 4:10, and not sure what's in Darin's. His was a non-OD car, so maybe a 3.73.

If his differential is original he most likely has a 390 or 410. Does he really have an overheating problem?

[Normspeed]

Probably runs a little warmer than optimum, considering it has freshly rebuilt 230 motor, a very nice recored radiator, electric pusher fan. I recall checking the temp gauge using the pot of boiling water method, before he installed it, and it's accurate.

It was a hot day, probably well over 90, and a fairly steep twisty road for several miles of climbing. Gauge was up at the last short hash mark before the top of the scale. Never showed any sign of boilover at all though. It would have been a good test for me to follow him up there with my car and see how hot mine ran. Since the rebuild and fresh radiator mine runs really cool. But I notice the 53 has a whole lot more open space in the grille for airflow.

After that run, we did remove the stat and put in a quart of additive in the radiator, so we'll have to monitor it. Plenty of 90 degree weather predicted for the next week or more.

[47heaven]

Probably runs a little warmer than optimum, considering it has freshly rebuilt 230 motor, a very nice recored radiator, electric pusher fan. I recall checking the temp gauge using the pot of boiling water method, before he installed it, and it's accurate.

It was a hot day, probably well over 90, and a fairly steep twisty road for several miles of climbing. Gauge was up at the last short hash mark before the top of the scale. Never showed any sign of boilover at all though. It would have been a good test for me to follow him up there with my car and see how hot mine ran. Since the rebuild and fresh radiator mine runs really cool. But I notice the 53 has a whole lot more open space in the grille for airflow.

After that run, we did remove the stat and put in a quart of additive in the radiator, so we'll have to monitor it. Plenty of 90 degree weather predicted for the next week or more.

Norm, I took the car out yesterday when it was hot and it stayed pretty cool...not going over 180 the whole time. Maybe removing the thermostat and adding the additive really did help things, but you are right...the real test will be tomorrow or when the 100 degree weather comes around, but without air in the car, I'm sure I won't be driving it too long. By the way...the NHRA Twilight Cruise is tomorrow at the fair. I plan on going to it. Maybe see ya there???

[Don Coatney]

Probably runs a little warmer than optimum, considering it has freshly rebuilt 230 motor, a very nice recored radiator, electric pusher fan. I recall checking the temp gauge using the pot of boiling water method, before he installed it, and it's accurate.

It was a hot day, probably well over 90, and a fairly steep twisty road for several miles of climbing. Gauge was up at the last short hash mark before the top of the scale. Never showed any sign of boilover at all though. It would have been a good test for me to follow him up there with my car and see how hot mine ran. Since the rebuild and fresh radiator mine runs really cool. But I notice the 53 has a whole lot more open space in the grille for airflow.

After that run, we did remove the stat and put in a quart of additive in the radiator, so we'll have to monitor it. Plenty of 90 degree weather predicted for the next week or more.

If it cooled down once over the hill it sounds normal to me. My engine does the same.

[BeBop138]

Greg G---it has an adjustable vacumm can and has a whole new set of wieghts and springs to handle the situation you mentioned. The specs are one degree off from factory and I am running about 10 degrees advanced on the wheel. It pulls strong and starts great, the car runs so much better. The Chev fits so nice in the block and all the parts are readily avaliable. I have it in a 265 and all that was in the way to mount it was the dipstick tube----just bent it slightly and everything cleared. I belive it`s better than Tom`s unit as there is no drift in the mechanical advance----this one has no slop in the shaft to pump so the timing is right on the money.

[martybose]

But Tom is an engineer and everything should be thouroughly figured out. Chevy distributors advance works almost opposite of MOPAR. The mechanical advance has a much steeper curve and the vacuum being on the manifold serves to retard the timing as the vacuum builds. (snip)The ported vacuum of the MOPAR design anticipates the additional advance with the vacuum signal from the carb.

Actually I think you have the vacuum advance description backwards. With manifold vacuum you have the maximum advance when the throttle is closed, and lose advance as the throttle is opened. With ported vacuum, you have minimal advance at idle, but pick up more advance as the throttle is opened enough to activate the vacuum port above the throttle plate. After you reach a certain throttle position the vacuum advance will start to back down as you approach full throttle.

I wish I could find the thread that had the description of the overall advance on a stock Mopar flathead at various road speeds; it made interesting reading!

Marty

[greg g]

Which is why it calls for such a great intial advance setting. Witht he vacuum disconected, the weight flyou even at idle, connecting the vacuum from the manifold retards the high initial setting, then when you accelorate, the centrifigul takes over against the dropping vacuum, as the vacuum builds as the throttle is released the vacuum pull the timing back to a more retarded state.

my manual calls has a chart which gives the advance per rpm for the different distributors. I think a recal 24 to 28 as being max advance, and it begins at to move at 600 rpm. I will dig it out later and post the info.

Both systems will reach a point of equalibrium soewhere in the rpm range. as the vacuum builds at cruise.

[jd52cranbrook]

Which is why it calls for such a great intial advance setting. Witht he vacuum disconected, the weight flyou even at idle, connecting the vacuum from the manifold retards the high initial setting, then when you accelorate, the centrifigul takes over against the dropping vacuum, as the vacuum builds as the throttle is released the vacuum pull the timing back to a more retarded state.

my manual calls has a chart which gives the advance per rpm for the different distributors. I think a recal 24 to 28 as being max advance, and it begins at to move at 600 rpm. I will dig it out later and post the info.

That would be good reading.

[martybose]

Which is why it calls for such a great intial advance setting. Witht he vacuum disconected, the weight flyou even at idle, connecting the vacuum from the manifold retards the high initial setting, then when you accelorate, the centrifigul takes over against the dropping vacuum, as the vacuum builds as the throttle is released the vacuum pull the timing back to a more retarded state.

my manual calls has a chart which gives the advance per rpm for the different distributors. I think a recal 24 to 28 as being max advance, and it begins at to move at 600 rpm. I will dig it out later and post the info.

Both systems will reach a point of equalibrium soewhere in the rpm range. as the vacuum builds at cruise.

Greg,

I'm sorry if it seems like I'm arguing with you, but you still have it wrong! Langdon recommended high initial advance with ported vacuum. With that setup as soon as you stepped on the throttle you would start to pick up more vacuum (ergo more advance) and would start to pick up centrifugal advance (even more advance). When I checked my HEI, I could pick up 19 degrees of advance with vacuum only and 13 degrees with centrifugal only by 2800 RPM. If you started with 10 degrees you could wind up with 10+29+13=52 degrees advance (if it maintained enough vacuum at 2800 RPM, which is doubtful). I tried his setup when I first installed the HEI; it was almost impossible to start the motor, I saw over 40 degrees of total advance just revving it in my garage, and it detonated like crazy on the road. I drove one block, turned around, and carefully idled back to my garage.

Now I'm running 4 degrees initial with manifold vacuum and no centrifugal advance. So I start with 4+19=23 at idle, drops to 4 degrees at WOT, and pulls back to maybe 20 degrees at cruise. A different approach,but it works well for me; no pinging, doesn't heat up at highway speeds, good throttle response. As always, YMMV.

Respectfully, Marty

[jd52cranbrook]

Marty are you still running with the weights tied?

[Don Coatney]

Greg,

I'm sorry if it seems like I'm arguing with you, but you still have it wrong! Langdon recommended high initial advance with ported vacuum. With that setup as soon as you stepped on the throttle you would start to pick up more vacuum (ergo more advance) and would start to pick up centrifugal advance (even more advance). When I checked my HEI, I could pick up 19 degrees of advance with vacuum only and 13 degrees with centrifugal only by 2800 RPM. If you started with 10 degrees you could wind up with 10+29+13=52 degrees advance (if it maintained enough vacuum at 2800 RPM, which is doubtful). I tried his setup when I first installed the HEI; it was almost impossible to start the motor, I saw over 40 degrees of total advance just revving it in my garage, and it detonated like crazy on the road. I drove one block, turned around, and carefully idled back to my garage.

Now I'm running 4 degrees initial with manifold vacuum and no centrifugal advance. So I start with 4+19=23 at idle, drops to 4 degrees at WOT, and pulls back to maybe 20 degrees at cruise. A different approach,but it works well for me; no pinging, doesn't heat up at highway speeds, good throttle response. As always, YMMV.

Respectfully, Marty

Marty;

I dont recall but did you call and discuss this with the engineer Tom Langdon?

[martybose]

Marty;

I dont recall but did you call and discuss this with the engineer Tom Langdon?

No, I had enough of his attitude when I talked to him about jets for the Carter-Webers.

Marty

[jd52cranbrook]

I found this from a previous thread. Is there a chart or info that would show optimum advance for matching rpm?

I'd really like to get this set correct.

[Powerhouse]

Just curious as to what settings you ended up using. Thanks.

[fedoragent]

Just curious as to what settings you ended up using. Thanks.

I'd like to know as well as this is the direction that I would like to go soon.

FG.

[dezeldoc]

No, I had enough of his attitude when I talked to him about jets for the Carter-Webers.

Marty

Ol Tom isin't as sharp as he thinks he is. when i had a problem with mine i talked to him and he was dead set on it being the coil as he says the module never goes bad on these things, and since i was running a MSD coil and not the one he says to run that was definitely the problem. well experience had told me otherwise, so i replaced the coil knowing that was not the problem, same thing. so i went and got a module and sure enough the module was bad. also talked about using the B&B's on the 218 and told him what was done to the motor and he said the B&B's would be way to much fuel, that the webbers were the way to go as they would flow the right amount. strange i thought the webbers flow more cfm than the B&B's. it runs fine with the B&B's if anything it is a tad lean.