Carb selection advice for a Tunnel Rammed 632 cube BBC

[cluxford]

I have a crate motor that came with a 1050 Dominator on a dual plane manifold

I want dual carbs...yes for the look, but my car is as much show car as it will be driver

For registration I need to keep everything real low. So I bought an Edelbrock C-66 dual quad manifold and twin 600's

Everyone telling me the engine will starve with these

I've done lots of research and I am no expert when it comes to dual carb setups, only ever had single carb engines before now

First off been told dump the Ede's as to hard to tune,
secondly they are too small,
thirdly the C-66 manifold is low rise and with such short runners, while I will have incredible low end torque (not that I need anymore with 632 cubes) I will significantly impact my top end speed (not that the car will be raced in it's first 2 years anyway)

So my plan was to go blown / injected. But I just can't afford that right now...so that's long term plan

For rego I'll just drop the 1050 back on

Here is the current plan.

Sheet manifold tunnel ram. Runners not too long but not too short...almost a street ram.

Now the tough question. I'm probably going to buy Demon carbs.

King's have a Holley 4500 flange, Mighty's and Race Demons both have Holley 4150 flange.

Kings start at 1050 CFM, Mighty's and Race top out at 1000 CFM

My question is what size twin carbs should I run, I am thinking 1000 CFM TR Race Demons.

I've been told too smaller carbs give better velocity on a TR, but also heard two big carbs are needed to feed such a big motor

Specs:
Cam 220 degrees
TH400 with 3000 stall
3.55 gears
29.5" tyre

I know I will need to play with advance and retard on the motor to tune in idle and max power.

Thanks so much in advance guys for your advice

Chris

[myss427]

220 degrees cam on a 632 cube motor is very very small, you could go 240 and it would still be a baby cam with that many cubes. At Powercruise B&G had some very nice sheet metal manifolds there, should check them out!

[Dynoryder]

the 600's would be fine for the manifold

but useing ram means higher rpm if it's custom most likely the runners are smooth on the inside so it needs to be at high rpm to achieve max power in this case you will need twin 1000's or 1200's for hig rpm

with cams just go max lift with your desierd lsa cant go wrong (with a expert grinding it)


with the carbs i have seen a v12 715ci running two 350holley two barrels it only usally sits at 2000rpm but can hit 4000max if this engine was to be reving at say 8000 it would massive carbys this is what i was talking bout with the rpm

[Dynoryder]

what stallie are you running the edlebrock setup would with the right cam give you heaps of low down grunt used with the right stallie can be impressive

[Dynoryder]

oh yea what compression do you have this is important when selcting lsa on the cam which will govern the discsion on what rpm you want wich is the choice between th 1000's and the 1200 carbys

[cluxford]

Originally Posted by Dynoryder

oh yea what compression do you have this is important when selcting lsa on the cam which will govern the discsion on what rpm you want wich is the choice between th 1000's and the 1200 carbys

Dynoryder, thanks for the advice

It's a 10.4 : 1 compression
Stall is a TCE 3000 converter
rear gears are 3.55

I know on the current manifold the torque will be through the roof with such short runners

I thought about a sheet metal intake but damn pricing them up today I ain't doing that, I will save my pennies for the injected blower I'll drop on it in a year or so. I thought with a sheet metal intake I could have best of both worlds by essentially having it custom made with mid range length runners

So now I'll probably go a Dart cast BBC Tunnel Ram with twin 1025 CFM Race Demon RS carbs. Good part of these is I can change the venturi and baseplate up to 1050 CFM. I doubt i will need bigger than that.

Engine currently makes peak HP at 4300 RPM, I doubt I will be getting into the 7000+ RPM range

Again advice always welcomed.

Dart TR + twin 1025 race Demons do the job ????

[ima400]

Originally Posted by cluxford

Dynoryder, thanks for the advice

It's a 10.4 : 1 compression
Stall is a TCE 3000 converter
rear gears are 3.55

I know on the current manifold the torque will be through the roof with such short runners

I thought about a sheet metal intake but damn pricing them up today I ain't doing that, I will save my pennies for the injected blower I'll drop on it in a year or so. I thought with a sheet metal intake I could have best of both worlds by essentially having it custom made with mid range length runners

So now I'll probably go a Dart cast BBC Tunnel Ram with twin 1025 CFM Race Demon RS carbs. Good part of these is I can change the venturi and baseplate up to 1050 CFM. I doubt i will need bigger than that.

Engine currently makes peak HP at 4300 RPM, I doubt I will be getting into the 7000+ RPM range

Again advice always welcomed.

Dart TR + twin 1025 race Demons do the job ????

if you only want to this once ring pro system carby's in the states & they will set you in the right direction . they want sell you somthing you dont need

[eh468]

Originally Posted by cluxford

Dynoryder, thanks for the advice

It's a 10.4 : 1 compression
Stall is a TCE 3000 converter
rear gears are 3.55

I know on the current manifold the torque will be through the roof with such short runners

I thought about a sheet metal intake but damn pricing them up today I ain't doing that, I will save my pennies for the injected blower I'll drop on it in a year or so. I thought with a sheet metal intake I could have best of both worlds by essentially having it custom made with mid range length runners

So now I'll probably go a Dart cast BBC Tunnel Ram with twin 1025 CFM Race Demon RS carbs. Good part of these is I can change the venturi and baseplate up to 1050 CFM. I doubt i will need bigger than that.

Engine currently makes peak HP at 4300 RPM, I doubt I will be getting into the 7000+ RPM range

Again advice always welcomed.

Dart TR + twin 1025 race Demons do the job ????

been told that the 632 don't go well with blower about 540 is the max but its just a crank change out to reduce stroke. What heads are fitted as I found that not many manifolds around for big after market big duke and big chief heads so bg are making my manifold at the momment.

[eh468]

just notice and read your members ride thread and its a world products engine I didn't look into world products heads so can't comment on whats available good luck with manifold though keep us posted.

[cluxford]

Originally Posted by eh468

just notice and read your members ride thread and its a world products engine I didn't look into world products heads so can't comment on whats available good luck with manifold though keep us posted.

Thanks, yeah heads are Merlin III Aluminium 24 degrees

Spoke with BG today gees they make some sweet looking manifolds

I def want to go blown so will hold out my $$ for that and just go cheap tunnel ram in the short term

Thanks for the advice though