24vdc air pump for coil cooling?

[ZGjethro]

I have a neighbor who has recently gone to a non-stock carb from VPW. He has no possible connections for the distributor cooling lines at the air intake, as the carb sits right on the intake manifold. I suggested he use the vacuum boost pump on the fuel pump to circulate air through the distributor, using a filter on the intake line. He has an electric fuel pump, but the stock pump is still in place and he is running electric wipers, so I don't see a problem with using the booster pump to cool the coil.

As a second option, has anyone here ever run a 24vdc air pump to cool the stock coil/distributor? I was thinking of something like this http://www.hadleyadvantage.com/products ... ompressors. It seems like a complicated solution to a simple problem. The original vacuum system involved no moving parts and worked pretty well from what I have read. Does anyone have any other views or opinion? Or questions about what I am asking about?

Thanks
John

[w30bob]

Hey John,

I don't know what type of air cleaner your buddy is using, but the simple solution is to put a spacer between the air cleaner body and the carb.....and then drill and tap holes in the spacer to connect the vent fittings. If the air cleaner body is long enough he could even drill and tap that and put the fittings directly into the air cleaner body. That assumes the air cleaner has a body......an all rubber K&N type filter won't work. You don't want to pull vacuum from under the carb, as that would just be a big air leak and lean out the mixture.

regards,
bob

[RMS]

what is the height difference between the 32/36 dgav weber with vpw adapter compared to the carter? with the webers flat 4 bolt flange wouldn't it be easy to make up a neck @45deg that conects to the stock 3 bolt flange of the stock air cleaner adapter ? if there's not the space for a neck on top put the hole carb in a box like you were running a turbo then there would be plenty of places to put the stock breather fittings.

[ZGjethro]

It looked like he had a spacer of maybe 2" height under the carb. The air cleaner sits right on top of the carb, not off to the side like stock. I don't know if he has room to extend the intake before the carb to accommodate the vent fittings

[w30bob]

ZG,

The fittings need to be between the carb and air filter, not between the carb and manifold. Putting them between the carb and the intake gives the engine a way to suck air into it that hasn't passed thru the carb....which will lean out the mixture.

regards,
bob

[RMS]

I would toss the look alike k&n air filter as it is likely for track use and not intended for severe off road duty or a dusty road.
I would build a horn that would adapt to the stock air cleaner elbow's three bolt flange. something like this but with a flange :

if hight/shrouding is an issue ( I dont think it will be as the carter is 8.5in from the base to the top of the 3 bolt flange and the 32/36 dgav is only 3.5in high plus the 2in spacer) I would build a blow through style box that the carb fits in with a hole on the side for the 3 bolt flange.
Mr Vorgons 510 with a blown through dgav

[ZGjethro]

Bob, I know those fittings are between the carb and air cleaner. Putting them after the carb would affect vacuum and run gas around the coil. I only mentioned the riser/adaptor height since it makes the carb sit higher, and his air cleaner (look like a pleated paper filter) sits on top of the carb. I don't know how much clearance he has under the hood to extend the intake tube.

RMS, I didn't follow you at all. He is not using any of the factory carb or intake or air cleaner. On my truck I made a flanged intake and stuck a K&N filter on it. I also ran all my vent lines (not brake or gas tank) into the horizontal intake.

He is running the Weber 270 CFM carb shown here http://www.vintagepowerwagons.com/pdf/parts/03fuel.pdf.

[RMS]

weber DGVA 32/36
the pic in the VPW catalog looks like a DGES 38/38 ? doesn't matter they have the same flanges.

RMS, I didn't follow you at all

let me tell it another way:

I was quite happy too see vpw come out with the weber adapter for the 2 bolt flange on the old flatty . what makes it even better is its only 30 bucks (without the carb). the weber is a very easy carb to service and tune with a wide selection of both fuel and air jets. the pump diafram is a little spendy @ $30+ but jets are like $5 . I have been running webers on my datsuns for years. I am not a fan of the small K&N lookalike air cleaner that is found with most weber conversion kits( like the one offered by vpw). ya its fine for the 2L on the track or at auto x but I would not run it on the rally car or the m37.
for my 265ci project I will run 2 of the VPW weber adapters on a cast dual plain intake. I will be running two DGVA 32/36mm webers (luckily all my webers are jetted for bored out 2L motors). I want to stick with an oil bath air cleaner but there is no room under the hood for two stock air cleaners and just the one may be restrictive . it would be easy if I was running only one carb.

With a single weber on a stock intake manifold it would be simple to keep the stock oil bath air cleaner with the aluminum air cleaner elbow and all those important breather lines. with the stock carter carburetor being over 8.5 inches from base to the top there is lots of room for a simple box on the top of the 3.5in(flange to flange) tall weber that can be bolted to both the weber and the stock air cleaner elbow at its 3 bolt flange.


with the dual weber setup its a bit harder. I could make a box that encompasses both carbs. that's right the carbs will be sealed in a box with a 4in pipe going out the fording hole to an old school diesel oil bath mounted were the jerry can should be. the only hard part will be sealing the mechanical linkage. I may have to go with a cable in the link. I know I don't need them in a box and the box could sit on top but what if I wanted to have it blown?

On my truck I made a flanged intake and stuck a K&N filter on it. I also ran all my vent lines (not brake or gas tank) into the horizontal intake.

sounds like you got the solution. I would tell the neighbor to toss the stock pump and blank off the hole. I dont like the idea of potentially having gas or oil pumped into my distributor

[MSeriesRebuild]

I have a neighbor who has recently gone to a non-stock carb from VPW. He has no possible connections for the distributor cooling lines at the air intake, as the carb sits right on the intake manifold. I suggested he use the vacuum boost pump on the fuel pump to circulate air through the distributor, using a filter on the intake line. He has an electric fuel pump, but the stock pump is still in place and he is running electric wipers, so I don't see a problem with using the booster pump to cool the coil.

As a second option, has anyone here ever run a 24vdc air pump to cool the stock coil/distributor? I was thinking of something like this http://www.hadleyadvantage.com/products ... ompressors. It seems like a complicated solution to a simple problem. The original vacuum system involved no moving parts and worked pretty well from what I have read. Does anyone have any other views or opinion? Or questions about what I am asking about?

Thanks
John

I'll add this; the original distributor vent system used on M37 is not a vacuum system. Instead it is a fresh air forced circulation system; that's why it is imperative that the correct fittings be used, and oriented the right direction for the system to work successfully. When the original set up is done right; I have seen no problems. In fact the only problem I have seen is some people simply refuse to do it right; you know there is always the few who know better regardless.

Many folks who acquire M37 trucks that have had the vent system removed, burn up numerous coils and have no idea why. Many have called me asking why coils keep failing; my first question is do you have the vent system in place and working correctly? Most often I get a lengthy pause after asking that question; they don't have a clue. In the large majority of cases; an explanation of how the system works and what they need to get it in place cures their coil failure problems.

I wouldn't consider fuel pump boost a good option, too risky. My response to a compressor system; I see no reason why it wouldn't work if a regulator was used to keep the air volume down to a gentle flow. I also see doing it this way kind of like going around the world just to cross the street. Why spend the extra cash to do this when a trouble free, no moving parts system works great; will cost far less to put in place, and nothing at all to maintain. The same type of forced air system can be designed into your buddy's new system. All it will take is some common sense design at the filters so the air will be forced to circulate, same as the original. Fairly simple to design and install.

[ZGjethro]

Thanks Charles. I set my intake up with the 90 degree fittings and it works fine, and agree, the stock system is super simple and has no moving parts to worry about. I get the feeling that he will just leave it as is until he burns up a coil or two. I will suggest he mimic the factory setup on his new carb. I was just bouncing a few other ideas off the members here.