Holley 850 dp

[Hoosier Bird]

Well, I was having some reliability issues out of my Edelbrock carb, prolly since I let it sit on the shelf for 8 years.....put a buddy of mines Holley 750 dp on, ran good at WOT but bucked around alot on primary circuit......didn't really want to tweak it in just to give it back so I broke the 850 dp out, put a kit in it, cleaned everything, did find a couple air bleeds clogged. Here is my starting point: Since the engine was pulling 9hg vacuum I used 4.5 power valves. 78 jets on primary, 76 jets on secondary. 31 squirters on primary and secondary. I've got a 50cc pump but leaving the originals on for now. White cam in #2 on primary and Green cam in #2 on secondary. Got ready to install and realized I didn't have the proper dual line so I will find out tomorrow..........Give me your comments PLEASE.....

 

[Hoosier Bird]

1 more

 

[ACME A12]

I like the first pic; I use Round Up on all of my carb rebuilds too...

Looks good, Gary. Once you do a couple of test launches out in front of the house you'll quickly know where you're at...

 

[Hoosier Bird]

I don't want any weeds growing in my carb...........

 

[Basketcase]

a can of raid wouldn't hurt either. I remember reading about a six barrel 'cuda that had a carb fire cause a fly got in the car and caused it to flood, and the gas hit the headers.

 

[dobie]

Looks good. I currently have a 650 DP on my car. I also have a 700 or 750 DP sitting on the shelf. For some reason my car hates the bigger carb. It bucks and bounces around as you say on mine too. With the 650 it's nice and smooth, with plenty of oomph behind it.


:huh:

 

[Hoosier Bird]

Hey Dobie, do you know what jets, pump cams, squirters, power valves and pump size you had on that carb? :huh:

 

[dobie]

I have the jet sizes written down somewhere. Everything else should be factory specs. The guy who rebuilt them always starts at factory specs, then goes from there per the customer. The 700 or 750 never ran right from the beginning. I know we changed jets a few times, but it never really solved the problem. The car was even harder to start with the bigger carb.

I'll look around for those numbers.

 

[Hoosier Bird]

Haven't fired it up yet. Waiting on the clear laquer to dry on the timing tape. If you do this be very careful and put a few light coats on first. It makes the black run on these Mr. Gasket tapes..........

 

[69hemibeep]

Looks good how soon

 

[Hoosier Bird]

Ok, runs very, very good.........smooth through all rpm range. Serious hesitation. Moved the pump cam to slot 1 and improved just a little. I'll have to pick me up a set. If I pump the front pump manually just before accelerating there is no hesitation. We shall see.....so far, I'm happy. :yesnod:

 

[dobie]

Looks good!

 

[mcmopar]

Ok, runs very, very good.........smooth through all rpm range. Serious hesitation. Moved the pump cam to slot 1 and improved just a little. I'll have to pick me up a set. If I pump the front pump manually just before accelerating there is no hesitation. We shall see.....so far, I'm happy. :yesnod:

Seems like that would indicate you need either a higher capacity pump or a longer duration on the squirt feed, or both.

 

[Hoosier Bird]

I do have a 28 squirter and a 50cc pump. This is the fun part...... Until nothing works and then it becomes the pain in the butt part......

 

[mcmopar]

OK - a 50cc pump should be fine. Try a 30-32 shooter. I had to put a bigger one on my 750 and it helped solve some off-idle issues. Also check your pump shot cam (as you mentioned earlier). If you can get one that will cause a longer duration pump shot it would help get you past the stumble.

 

[69hemibeep]

OK - a 50cc pump should be fine. Try a 30-32 shooter. I had to put a bigger one on my 750 and it helped solve some off-idle issues. Also check your pump shot cam (as you mentioned earlier). If you can get one that will cause a longer duration pump shot it would help get you past the stumble.

I have a cam kit but but no sheet to explain the progression of each cam or hole. Does any one have one they can scan and post?

 

[Hoosier Bird]

OK - a 50cc pump should be fine. Try a 30-32 shooter. I had to put a bigger one on my 750 and it helped solve some off-idle issues. Also check your pump shot cam (as you mentioned earlier). If you can get one that will cause a longer duration pump shot it would help get you past the stumble.

Right now I do not have the 50cc pump on the carb and I have a 31 squirter in it........

 

[ACME A12]

I have a cam kit but but no sheet to explain the progression of each cam or hole. Does any one have one they can scan and post?

I was looking for the same thing earlier today...be nice to know the properties of each color...

Probably frightens you a little that we are on parallel wave lengths...

:jester:

 

[Basketcase]

lookin good Gary

 

[moparchris]

Gary, your jet spread is kinda backwards and small in the secondary....unless you have a secondary power valve.......then I am full of sh&t. But you already knew that.