700 double pumper on a road car

Guy · Post by **Guy** » Tue Sep 02, 14 10:43 pm

Guy wrote:
GJUK wrote:I will lob this 750 vac sec Holley I have bought on
I meant the bowls off of the 750 vs he has, sorry for any confussion

Funny thats what I said

Dave81 · Post by **Dave81** » Tue Sep 02, 14 10:50 pm

My advice is take a week or two off...........you seem to be at the point we've all been too (I was ready to torch mine three months ago)!

I was advised as above.........worked too. Recharged and restarted with lower blood pressure!

Problem solved!

Have you thought about sending it to one of the guys on here to get it sorted for once and all?
Not in the spirit of learning and tinkering, but at some point you have to wave the flag rather than throwing money at parts in a hope it may solve the issue!

Hope you get it sorted mate!

Mick · Post by **Mick** » Tue Sep 02, 14 11:08 pm

Jon, stick with it, swap the float and bowl onto the Dp and slap it on.

GJUK · Post by **GJUK** » Wed Sep 03, 14 9:01 am

Hi Everyone

I'm sorry I had a bit of a moan about everything yesterday, long days at work and only a couple of hours in the evening to make a lot of noise due to the neighbors, they've not complained yet but I bloody would. It's every night right now meh.

I've taken the vac 2ndry carb off this morning and dragged both carbs to work with me to swap the float chamber over.

...I always end up with two or three of everything when I work on cars.

Thanks guys.

Jon

GJUK · Post by **GJUK** » Wed Sep 03, 14 9:08 am

Guy wrote:
Guy wrote:
GJUK wrote:I will lob this 750 vac sec Holley I have bought on
I meant the bowls off of the 750 vs he has, sorry for any confussion

Funny thats what I said

Thanks Guy, I was hoping this new known working carb would just bolt on and go. Seems my cam overlap might be causing some weird requirement for a funky not normal carb spec.

Guy · Post by **Guy** » Wed Sep 03, 14 11:03 am

I am off work on Friday if you can get time off during the day, I can pop up if you want, let me know Jon..

GJUK · Post by **GJUK** » Wed Sep 03, 14 11:38 am

Guy wrote:I am off work on Friday if you can get time off during the day, I can pop up if you want, let me know Jon..

Hi mate,

That's very kind buy im out on the road Friday :-/

I'm going to try and swap these bowls over at lunch time and bosh the carb (DP) on the car again.

I'm around Sunday...

Guy · Post by **Guy** » Wed Sep 03, 14 11:54 am

Sorry mate, i'm working Saturday-Tuesday off Wednesday back in Thursday and Friday. So if you have no joy swapping the bowls over I could do Wednesday if you want.

GJUK · Post by **GJUK** » Wed Sep 03, 14 1:16 pm

Hi Guy,

Yeah I might be able to to take a day off work next week, that's very kind of you - cheers mate.

I have just stripped the two carbs on my work desk in the office

I did not swap the bowls over as I ran a bit out of time (after getting in a muddle of which was front and rear) but I have swapped the floats over (from the other carb which were neoprene) and do not sit on the bottom of the bowls. I've also swapped out both of the float needles as I know they both work on the old 750 vs carb.

The 6.5 PV is now back in the double pumper and I hope all of the above might cure the flooding issue.

If i get no flooding issue but still a backfire it has to be something else, like timing again.

So.... Carb change number 6, the old ones going back on now with new floats (known working) and needles (known working).

GJUK · Post by **GJUK** » Wed Sep 03, 14 9:55 pm

Hi guys.

So. I have now put the new floats from the Vac 2ndry carb in to the DP.

DP is back on the car and it started well, warmed up well and revved clean (ish) to 4k.

No pops or bangs that I could tell and I went from 0 on the pedal to all the way down, 'snapped' the pedal to the floor, no issues.

Did this three times and couldn't see any issue other than a.

REEEE-small gap-eeeeeeeeeeeeeev almost like going from primary to secondary circuits perhaps, but what do I know.

No leaks so far anyway and the float levels are bang on again.

PSI below 6 all the time.

Road test tomorrow after work.

Mossy68 · Post by **Mossy68** » Wed Sep 03, 14 10:01 pm

Sounds like your getting there mate. Keep at it.
Well done.

Guy · Post by **Guy** » Wed Sep 03, 14 10:40 pm

Sounds promising Jon, if you can drive it get it to the HRDs and I will go through it for you mate, if you cant I will pop up Wednesday

GJUK · Post by **GJUK** » Wed Sep 03, 14 10:43 pm

Thanks Mossy.

Thanks Guy, will let you all know how tomorrows test drive goes, I would have taken it out tonight but you know. It's ****ing loud

GJUK · Post by **GJUK** » Thu Sep 04, 14 9:50 am

Hi,

Quick question on tuning and accelerator pump:

I read somewhere and I may have misunderstood that I needed .15" between the arm of the pump and the arm of the carb (I set this when the car throttle was at O and 'resting')

Now I have read this:

If end play is too much you lose pump action, if it’s to little you end up destroying the pump. End play is determined by opening the throttle fully (engine off) and then seeing how much further you can press the accelerator pump at the are situated on the fuel bowl. You should be able to create a gap of 0.4mm, adjust spring just above to obtain that.

So I should be setting this gap when the throttle is wide open?

Maybe thats a bit of a cause for my small gap when revving.

Blue · Post by **Blue** » Thu Sep 04, 14 10:46 am

All I ever do is adjust the pump arm just a smidge past zero clearance, and then hold the throttle wide open and press down on the pump arm to check there's some movement left, that's it. Pump delivery is controlled by the pump cam, set up my way you must get as big a shot as is possible with any given cam.

Mopar Muscle Association UK

700 double pumper on a road car

Tuning the accelerator pump question