BIGS or \barry Grant HP 750 carb
BIGS or \barry Grant HP 750 carb
Author
Discussion

V8Dom

Original Poster:

3,547 posts

231 months

Wednesday 2nd September 2009
quotequote all
thinking of changing my 750 carb for a HP carb

Have any of you had any dealings with Bigs or Barry Grant carbs????

Supposed to be var batter than standard HP750

Ive decided on the BIGS carb unless you guys point me another way......even fuel injection???



dom

Gulf -LS2

1,922 posts

233 months

Wednesday 2nd September 2009
quotequote all
you know my views Dom.....

you have a race engine until the cam is milder it is always going to be choppy.

V8Dom

Original Poster:

3,547 posts

231 months

Wednesday 2nd September 2009
quotequote all
well i know until i leaned of idle screws at Martins and no next to no bog??????

Also did a test on the way home...

removing the reverie airbox caused the engine to run richer.......2 marks on the air. fuel guage.....

refitted it runs leaner again......

wow that works well with the rear clip inlet..


looking at HP carb as ive always got more horsepower with them and i run no choke anyway....


otherwise if i win the lootery LS???


Good to see you Karl/... glad its all working 4 u.... wish id come on board when we spoke a long time ago about MOT station and LS fitter...Great outfit you have there...
Dom

Edited by V8Dom on Wednesday 2nd September 20:48

738 driver

1,202 posts

222 months

Wednesday 2nd September 2009
quotequote all
Dom, I think you already have previous contact with Joe Sherman (big joe the engine masters man).............he has an excellent local carb builder who will, when provided with 'full' engine specs, custom build your carb to within minor adjustment (idle mixture adjustments contribute to your main/top-end too!)

The optional 'road-race' floats and bowls might be a good request too.......if you are planning a trackday or two.

Good luck.


Edited by 738 driver on Wednesday 2nd September 23:14

Boosted LS1

21,200 posts

289 months

Wednesday 2nd September 2009
quotequote all
Not as much as power valves and pvcr's though smile Idle and transition slots get things moving towards the main jets and then the pv's take over. I like the holley's but the BG's or Demon's look impressive. I never got to try one but reckon they'd be worth trying.

V8Dom

Original Poster:

3,547 posts

231 months

Thursday 3rd September 2009
quotequote all
738 driver said:
Dom, I think you already have previous contact with Joe Sherman (big joe the engine masters man).............he has an excellent local carb builder who will, when provided with 'full' engine specs, custom build your carb to within minor adjustment (idle mixture adjustments contribute to your main/top-end too!)

The optional 'road-race' floats and bowls might be a good request too.......if you are planning a trackday or two.

Good luck.


Edited by 738 driver on Wednesday 2nd September 23:14
Hi yes had long chats with Joe regarding my old tiger engine... very impressed with him..

Bigs carbs are built to engine spec as well..with race floats extended mains, etc etc

Do you know if Joe uses bigs?? or is it someone different??

Dom

MHunter

125 posts

220 months

Thursday 3rd September 2009
quotequote all
V8Dom said:
looking at HP carb as ive always got more horsepower with them and i run no choke anyway....
I don't want to hijack the thread, but do you have any problems running with no choke? I find my engine is often difficult to start, and just dies unless I keep my foot on the throttle (~2000rpm) for at least a minute.

Wilder

1,509 posts

238 months

Thursday 3rd September 2009
quotequote all
Well i have a BG 750cfm carb. Ive only done 200 miles from new with it.
It was smooth and I really liked it.
I opted for a bigger carb due to an engine change.

Edited by Wilder on Thursday 3rd September 02:32

GTRCLIVE

4,193 posts

312 months

Thursday 3rd September 2009
quotequote all
I know a certain Engine builder that Hates BG's..... things may have changed but I'm guessing not..... and he spends alot of time on his the Dyno so I trust he knows better than most of us...

cliveg

199 posts

273 months

Thursday 3rd September 2009
quotequote all
[quote=MHunter I find my engine is often difficult to start, and just dies unless I keep my foot on the throttle (~2000rpm) for at least a minute.

[/quote]
No problems starting, but I do need to keep it running for a minute or two before it will idle.

Boosted LS1

21,200 posts

289 months

Thursday 3rd September 2009
quotequote all
GTRCLIVE said:
I know a certain Engine builder that Hates BG's..... things may have changed but I'm guessing not..... and he spends alot of time on his the Dyno so I trust he knows better than most of us...
Does he sell carbs or efi though? I can see where carbs have their place certainly where simplicity's concerned. I've used both and whilst efi's wonderful I do miss my holley's in some respects. It used to be fun tinkering with a screwdriver and swopping componants before going for a blat.

k wright

1,039 posts

288 months

Thursday 3rd September 2009
quotequote all
Whatever you get make sure that it has annular discharge boosters. As far as I know that excludes anything from Barry Grant unless it it a Dominator style carb.

GTRCLIVE

4,193 posts

312 months

Thursday 3rd September 2009
quotequote all
Boosted LS1 said:
GTRCLIVE said:
I know a certain Engine builder that Hates BG's..... things may have changed but I'm guessing not..... and he spends alot of time on his the Dyno so I trust he knows better than most of us...
Does he sell carbs or efi though? I can see where carbs have their place certainly where simplicity's concerned. I've used both and whilst efi's wonderful I do miss my holley's in some respects. It used to be fun tinkering with a screwdriver and swopping componants before going for a blat.
Both..... Mainly Carbs engines I think, but has some nasty stories about the BG's. Having to completey rebuild certain carbs as the fuely was crap, and by the time He's spent fixing it would have been better of buying another carb... I bought my "Chuck Nyton" (Modidied Holley) 750 DB from him it was his old Dyno Carb, and looking at my O2 sensor when I drove my GTR the thing was perfect under all amounts of throttle....

V8Dom

Original Poster:

3,547 posts

231 months

Thursday 3rd September 2009
quotequote all
MHunter said:
V8Dom said:
looking at HP carb as ive always got more horsepower with them and i run no choke anyway....
I don't want to hijack the thread, but do you have any problems running with no choke? I find my engine is often difficult to start, and just dies unless I keep my foot on the throttle (~2000rpm) for at least a minute.
choke are a pain for V8 and never seem to need them.... 2 pumps of the gas and she is up and running...yes you have to keep your foot on the gas for a while or use the choke as a higher idler rather than enrichment... ive removed my choke flap and noticed an increase in power..........

so no....no choke needed... unless its winter and lets face it do you drive your car in -5 degrees??


dom

V8Dom

Original Poster:

3,547 posts

231 months

Thursday 3rd September 2009
quotequote all
k wright said:
Whatever you get make sure that it has annular discharge boosters. As far as I know that excludes anything from Barry Grant unless it it a Dominator style carb.
wasnt looking at domi carb but hp750 modified...
as in

750 version here

http://www.bigsperformance.com/productpage.htm

what do you think???? i ve heard or Barry Grant but not bigs???????

dom

738 driver

1,202 posts

222 months

Thursday 3rd September 2009
quotequote all
Do you have all the specs of your motor Dom? Bore, stroke, rod length, cam-card figures,head flow numbers,C/R etc.....if so there are several top US Carb-builders you should speak with. If they are not requesting the sort of information listed above, I would question how they will spec your custom build????

V8Dom

Original Poster:

3,547 posts

231 months

Thursday 3rd September 2009
quotequote all
738 driver said:
Do you have all the specs of your motor Dom? Bore, stroke, rod length, cam-card figures,head flow numbers,C/R etc.....if so there are several top US Carb-builders you should speak with. If they are not requesting the sort of information listed above, I would question how they will spec your custom build????
hi yes they have asked everything.....

ive email the complete spec of engine including make.type size etc and even part numbers of some of the bits.......

ive also gone aqn internet search on bigs carbs and read some of the feedback on the forums which seem possitive...

ive never heard of them yet heard or Barry Grant.....

dom

V8Dom

Original Poster:

3,547 posts

231 months

Thursday 3rd September 2009
quotequote all
maybe i will investigate further

this is of interesting reading

http://www.hotrodders.com/forum/bigs-carbs-scammer...

dom

k wright

1,039 posts

288 months

Friday 4th September 2009
quotequote all
V8Dom said:
k wright said:
Whatever you get make sure that it has annular discharge boosters. As far as I know that excludes anything from Barry Grant unless it it a Dominator style carb.
wasnt looking at domi carb but hp750 modified...
as in

750 version here

http://www.bigsperformance.com/productpage.htm

what do you think???? i ve heard or Barry Grant but not bigs???????

dom
I don't think much of that carb. It has downleg boosters which will be less efficent at atomizing fuel than an annular booster carb. As a result you will need a rich mixture for drivability.

Quick Fuel 750 AN is the one that I have. Chuck Nyutten or The Carb Shop can supply you with a ready to run carburetor if you supply them your motor specifications and even better your dyno sheet with BSFC numbers.

V8Dom

Original Poster:

3,547 posts

231 months

Friday 4th September 2009
quotequote all
k wright said:
V8Dom said:
k wright said:
Whatever you get make sure that it has annular discharge boosters. As far as I know that excludes anything from Barry Grant unless it it a Dominator style carb.
wasnt looking at domi carb but hp750 modified...
as in

750 version here

http://www.bigsperformance.com/productpage.htm

what do you think???? i ve heard or Barry Grant but not bigs???????

dom
I don't think much of that carb. It has downleg boosters which will be less efficent at atomizing fuel than an annular booster carb. As a result you will need a rich mixture for drivability.

Quick Fuel 750 AN is the one that I have. Chuck Nyutten or The Carb Shop can supply you with a ready to run carburetor if you supply them your motor specifications and even better your dyno sheet with BSFC numbers.
thanks i will do some digging...

Dom