71dusterdude
Active Member
Okay guys...decided to bring in my folder of reciepts I got with the car....found the carb receipt....holley double pumper 750. Mystery solved..lol....somewhat.
Anyone have any experience with changing cams in crate?
- Thread starter 71dusterdude
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AdamR
Big Member
whats the model number on the holley, Theres a bunch of different version of the 750 double pumper,
The cams actual specs are
288 / 299 advertised Duration - 230/[email protected]" - 501 / 513 Lift 108lsa
I wouldnt bother with a can change, I would tune the crap out of it. Likely re-curving the distributor and fine tuning the carb will do wonders.
The cams actual specs are
288 / 299 advertised Duration - 230/[email protected]" - 501 / 513 Lift 108lsa
I wouldnt bother with a can change, I would tune the crap out of it. Likely re-curving the distributor and fine tuning the carb will do wonders.
71dusterdude
Active Member
Reciept does not say...but ill try to get the numbers off the carb possibly.......whats your take on the crate dizzys?....Ive heard there junk>?....mds? mallory? any suggestions or just tune the dis I have.
moper
Well-Known Member
I think the best thing would be to treat it as if there was nothing known about it. Start by checking the advance setup. What IS normal for a crate engine is things being a little off. Like the cam isnt degreed. The distributor probably has a curve that is not optimized. You need to get a realy good performance tune on it...
T67POWER
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I can tell you for sure that it should go MID 12's to HIGH 11's in a duster.
IF YOU WANT TO GET A GOOD START THEN HERE'S SOME HELP.
I would shift the engine at 6300 rpm and run a 26 inch tall tire.
Put the total timing at 38 and run a set of 3924 autolite racing plugs.(advanced auto has these in stock most of the time
Put a phenolic four hole 1 inch spacer under the carb.
Set up the carb like this.
72 front jets/82 rear jets
35 pump shots front and rear
3.5 power valve
Front pump cam screw setting ....1st hole on carb linkage and use the second hole on pink cam.
The rear cam leave in the stock position.1st hole on carb and cam.
Set the pump shot adjuster springs by tightening the screw and nut together making the arm for the accelerator pumps a little loose and not as tight as stock.
These are the pieces that set on the accelerator pump arms.
You want your total timing in by 2200 to 2400 rpm.
When you time the engine you will be able to tell when the full advance is in by.
You will need a timing light with a total advance dial on it to set your total advanced timing.
And don't forget a adjustable pinion snubber set about 3/4 of a inch from the floor.
I really don't know what you have for tools and or how much you know for information, so i gave you everything i could think of.
The carb and distributor timing are very important as well as traction.
GOOD LUCK......................:burnout:
IF YOU WANT TO GET A GOOD START THEN HERE'S SOME HELP.
I would shift the engine at 6300 rpm and run a 26 inch tall tire.
Put the total timing at 38 and run a set of 3924 autolite racing plugs.(advanced auto has these in stock most of the time
Put a phenolic four hole 1 inch spacer under the carb.
Set up the carb like this.
72 front jets/82 rear jets
35 pump shots front and rear
3.5 power valve
Front pump cam screw setting ....1st hole on carb linkage and use the second hole on pink cam.
The rear cam leave in the stock position.1st hole on carb and cam.
Set the pump shot adjuster springs by tightening the screw and nut together making the arm for the accelerator pumps a little loose and not as tight as stock.
These are the pieces that set on the accelerator pump arms.
You want your total timing in by 2200 to 2400 rpm.
When you time the engine you will be able to tell when the full advance is in by.
You will need a timing light with a total advance dial on it to set your total advanced timing.
And don't forget a adjustable pinion snubber set about 3/4 of a inch from the floor.
I really don't know what you have for tools and or how much you know for information, so i gave you everything i could think of.
The carb and distributor timing are very important as well as traction.
GOOD LUCK......................:burnout:
71dusterdude
Active Member
Thanks a ton t67....great info!......by the way is this street friendly set up or track low et only deal?
T67POWER
Well-Known Member
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Your engine can do both with the right set up.
The only thing that separates a race and or street car is the front gate at the track for most of us.
The carb settings I gave you will work and get results.
It should run and drive really good.
After running for a whileon the highway , check the plugs.
Drive at least 15 min above 3000 rpm
Pull over to a truck stop or off the highway and shut the car right off.
Pull cylinder 1 and cylinder 8 and see how the plugs look and go from there.
Remember that each barrel on your carb feeds the two closest cylinders.
If the carb is set up right,you should not need to use your choke.
When cold starting your car you should hit the gas 1 or 2 times and fire it right away keeping the rpm up to 2500 for about 30 seconds.
After 30 seconds rev the engine up a little over 3000 rpm and take your foot off the pedal.
It should idle at around 1100 rpms.
Don't bring the idle down to low.
The cam has a lot of over lap and you don't want to load up the plugs because of a low idle.
The only thing that separates a race and or street car is the front gate at the track for most of us.
The carb settings I gave you will work and get results.
It should run and drive really good.
After running for a whileon the highway , check the plugs.
Drive at least 15 min above 3000 rpm
Pull over to a truck stop or off the highway and shut the car right off.
Pull cylinder 1 and cylinder 8 and see how the plugs look and go from there.
Remember that each barrel on your carb feeds the two closest cylinders.
If the carb is set up right,you should not need to use your choke.
When cold starting your car you should hit the gas 1 or 2 times and fire it right away keeping the rpm up to 2500 for about 30 seconds.
After 30 seconds rev the engine up a little over 3000 rpm and take your foot off the pedal.
It should idle at around 1100 rpms.
Don't bring the idle down to low.
The cam has a lot of over lap and you don't want to load up the plugs because of a low idle.
Frost
Member
I have the same motor in my demon. I had to put drag radials on it just to keep it straight when I punched it. a good tune up and this is a strong motor.
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