young olds

It's hard to say if I gained anything going from the 650 to the 750, since the 650 has issues. The main reason for the switch was an idling problem

young olds

I made a limiter plate to limit my vacuum advance and found mine does not even work and was just acting as a vacuum leak. I swapped in a functioning one but have not tested it. I'm also working on getting the 650 cleaned out so I can try it again.

jpc647

Got a photo of this? Isn't that usually a screw mounted to a steel plate? How would it cause a vacuum leak?

young olds

The diaphragm in the vacuum advance can must have a tear in it as it does not work.

young olds

I got the engine running really good. I got some help from cliff Ruggles and set up a sweet quadrajet off a 69 tornado I saved a few years back. Anyway with the addition of a 1" tapered spacer and some parts from cliff it's like a whole new engine! Just my luck it took me this long and now I have to wait until next season to get to the strip.

wr1970

Well that is good news. Well you ended up with a 750 even if it is a quadrajet!I hope it runs as good as you expect. Thanks for the update.Take care and have a good holiday.Neeley

young olds

So far it runs like a dream compared to all the Holley style carbs I had on. I actually am very biased towards quadrajets but when I originally put this one on it had a pretty bad lean surge so I cast it aside. After all the fuss with Holley style carbs I decided it was Time to talk to cliff and get back to a quadrajet. I know holleys can run great but I believe in quadrajets for all aplications that are within there limits. Thanks and same to you

young olds

Trying to get my new combo dialed in. Changed the cam to .540 lift 227 duration single pattern, turbocharger, meth injection. I took the power piston out of the qjet and went with .065 main jets but left the sencondaries how they were. Finally got my wideband hooked up today and I'm going really lean under boost. I'm 12-13 afr cruising, depending on gear and rpm. But under boost I saw it go as lean as 16, dialing in the meth got me into the mid 15's. I'm hoping a simple secondary rod change will richen it up but any one have an idea of how much to richen it up( which secondary rod to try)?

cutlassefi

A bunch, but not sure you can get there with what you have. Your other problem will be the small bowl on Qjets that has to feed both the primary and secondaries. Good luck.

young olds

Yeah I know I'm working with a limited carb, but I just need it to run good enough to have fun with until I go efi

cutlassefi

I get ya but if you burn it up you're dead in the water. Don't apply boost until you're relatively sure you have enough fuel.
Now if you had EFI, one swipe of the mouse and you're there!! ;-)

young olds

Yeah, that's why I'm going for the change. I drive it to much to fool around with a carb. I'm going to work with cliff Ruggles some more with the qjet and hopefully get it set up right. He says a single qjet can support up to 700hp

young olds

Going to try an .030 extended tip secondary rod, will report back when I get it together