holley 850 dp 4781-3?

[flathead31coupe]

with my 66 dart and a mild built 440 I have a 850 holley that has percys adjust a jet blocks, 50cc pump pri and sec. with 41 squirters, I want to put back to out of the box cond except for the percys blocks. my Question should I go back to stock 850 and star from there, or this by sujestion.. Holley lists as having 80 front, 78 rear jets. 6.5 PV's in both. 31 squirters in both. My suggestion is ditch the secondary PV, jet it 88. Squirters may need to be larger, have 35 and 37 available as well. Use green pump cams, have blue available.

 

[justinp61]

I'd think 82/88 with no rear PV would be close. Also I don't see it needing 50ccpumps, try the 35's on the squirters, you may even go smaller and be good.

 

[flathead31coupe]

I'd think 82/88 with no rear PV would be close. Also I don't see it needing 50ccpumps, try the 35's on the squirters, you may even go smaller and be good.

I have the stock 31 shooters.. what about the cam colors...also is there any to tell if there is a a pv in the sec without taking it apart thanks

 

[justinp61]

I run pink cams with 30cc pumps. Keep in mind that 50cc pumps have their own cams, I've heard of guys using 30cc cams on them though.

 

[flathead31coupe]

I run pink cams with 30cc pumps. Keep in mind that 50cc pumps have their own cams, I've heard of guys using 30cc cams on them though.

thanks.... what I have now are the 41 that are in there and 31 that are not.. and a assorted pack of cams.. looking for the best combo to drive it some, until I can do real tuning... is there any way of telling if there is a pv in the sec without taking it apart... btw thank for the help

 

[flathead31coupe]

I'd think 82/88 with no rear PV would be close. Also I don't see it needing 50ccpumps, try the 35's on the squirters, you may even go smaller and be good.

35 squirters on both? and leave the 50cc and the brown cams on both? I want to be able to drive this around little before I go to the track for big tuining, looking foe a base starting poit that I can drive some... thanks

 

[justinp61]

Yes, both and I'm betting it could use 31's and be fine. Try the 50cc pumps and see, it may be fine with them but honestly I don't see it "needing" them. Drive it and see if you're happy and it's happy let'er rip.

 

[flathead31coupe]

Yes, both and I'm betting it could use 31's and be fine. Try the 50cc pumps and see, it may be fine with them but honestly I don't see it "needing" them. Drive it and see if you're happy and it's happy let'er rip.

thanks I just installed the 31s... was told by last owner of the carb it was on a super charged 340..so guessing no sec pv. may need to jet up to 88 from 80 in the rear...

 

[justinp61]

Set it up with the 82/88 no rear pv and see how it runs. If the plugs are black or sooty after cruising (no wot) you may need to jet down the primaries some more. When you pull the secondary bowl to change the jets if the metering block stays on the carb you can see if there is a pv or plug.

BTW, buy yourself some Superformance carb gaskets and throw away any Holley blue gaskets you have.

 

[flathead31coupe]

Set it up with the 82/88 no rear pv and see how it runs. If the plugs are black or sooty after cruising (no wot) you may need to jet down the primaries some more. When you pull the secondary bowl to change the jets if the metering block stays on the carb you can see if there is a pv or plug.

BTW, buy yourself some Superformance carb gaskets and throw away any Holley blue gaskets you have.

Thamks

 

[flathead31coupe]

Thamks

iam using the Percy adjust a jet blocks