is my carby too big?

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paully77galant
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Joined: Wed Dec 23, 2009 4:24 pm

is my carby too big?

Post by paully77galant »

I have a 1600 saturn engine(square port), that has 30thou bigger bore, ported and shaved head(10.5:1comp), with bigger valves and a 276 cam, tuned headers and a MSD 6AL with coil.
It also has a 465cfm 4 barrel holley on a modified inlet manifold.
Considering that i will be driving it daily in all conditions, is this carby way too big?
If it is what other carby options should i look into?
Superscan811
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Joined: Sun Mar 22, 2009 4:12 pm
Location: Sydney

Re: is my carby too big?

Post by Superscan811 »

Hell yes,
WAY TOO BIG.

The carb is rated for 465-cfm (13167-lpm).
At 8000rpm you are using approx 6400-lpm (approx226-cfm).
You would need to be spinning the engine up to 16,5000rpm to correctly use these carbs.


Cheers.
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paully77galant
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Joined: Wed Dec 23, 2009 4:24 pm

Re: is my carby too big?

Post by paully77galant »

Hahaha thanks for the info, i had a feeling it was miles off the mark.
So what should i be considering for a carby/+manifold to suit my application.
In the shed i think i have:
40mm delorto sidedraught
twin 35mm sidedraught solexs
the original carby and manifold

could any of those work or will a 2 barrel holley suit?
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75wagon
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Re: is my carby too big?

Post by 75wagon »

paully77galant wrote:In the shed i think i have:
40mm delorto sidedraught
twin 35mm sidedraught solexs
the original carby and manifold
All 3 of those options will work.
paully77galant wrote:could any of those work or will a 2 barrel holley suit?
What size is the Holley? 180 by any chance?
Isn't the 180 Holley a straight copy of the 32/36 downdraught weber?
If it is it might (depending on the way the carb is set up) be pretty easy to put on.

Dave...
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paully77galant
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Re: is my carby too big?

Post by paully77galant »

i dont have a 2 barrel, it'd just be an easy option to get one with an adapter plate to replace the MONSTER thats on there now.
I like the idea of the single dellorto DHLA as there is an affordable manifold availabe atm.
Otherwise could i just re-jet the original carby on the stock manifold?
I still wanna keep it to a reasonable budget...
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davetrees
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Re: is my carby too big?

Post by davetrees »

Single sidedaughts tend to not run all that great unless they are on a good "crossover" style manifold (they are really designed to work in pairs - 1 throat per cylinder). I suspect that 1 x 40mm might even be a little small ?

My suggestion would be to put a downdraught Weber on it - either a 32/36 DFEV or maybe even a 34ADM (which was the stock XE/XF Falcon carby & can be had virtually free 2nd hand. They use the same adapter plate to stock manifold as the 32/36). Then spend the money getting it properly jetted.
Superscan811
Posts: 1689
Joined: Sun Mar 22, 2009 4:12 pm
Location: Sydney

Re: is my carby too big?

Post by Superscan811 »

Quad 36mm motorbike carbs....
:D

Just ask Matt



Cheers.
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