chillbro

Hey guys, just picked up an old but recently rebuilt holley 3752 double pumper and i was wondering if anyone has ever set one up and used it on a 13b 4 port. I figured maybe someone out there could help me out and maybe give me advice on where to start with it (tuning wise). Now I know alot of people will not like the carb idea and may not like holley carbs but I don't care. I'm going to use it. A friend of mine is pretty confident in this carb and a couple other holleys. I just thought I might as well ask where to start. Just looking for a little help. thanks

SirCygnus

iTrader: (1)

go to the first gen section. they will be more helpful than we would be.

Valkyrie

...do you have a carb manifold?

Do you know how to set an ignition system for running a carb?

You will probably gain a bit of top end power (mostly from the manifold though) but you will lose bottom end driveability and the ability to not worry about the weather.

gerald m

I would like to see a few pic of that old carb . does it have a choke horn on it ? Does it have a little nub inside where the air screws go ?. I'm not against the Holley carb at all but if it's what I think it is your kinda overdoing it we use to run them on big block mopar stuff back in the 70's and 80's . One positive thing ,you shouldn't need to modify it much for the high demands of air that the rotary requires . Funny thing yesterday I'm having a discussion with a member about maybe his application is a tad small and then up pops this big boy . It must be fully mechanical . Do you have an intake or are you buying or building one ?

chillbro

im thinking i will be buying a j w performance manifold for it? ill throw up a couple pics if that could help. kinda new so gotta figure out this pic stuff.

chillbro

pics

Valkyrie

Completely modifying a car just because you bought one part is a really dumb idea. That's like spending $10,000 on a widebody kit because you found a good deal on some used rims that were too wide. There are almost certainly better carburetors for the RX-7 out there if you have to go the carb route, although a injection system with custom manifolds and throttles would work better...

chillbro

gotta start somewhere.

SirCygnus

iTrader: (1)

yeah. sell it dude.

Valkyrie

A turbo swap would be easier and probably cheaper in the long run if you can find a good deal on a drivetrain.

Of course you'd probably get more horsepower from your engine by simply rebuilding it than adding any parts.

Start somewhere that actually makes sense. You buy parts after you decide what will work, you don't decide what will work after you buy parts.

gerald m

Yea I'm afraid I have to agree with the rest of the guys . to start with there is no choke set up on that carb , by the looks of the throttle plates the carb might have new parts but was NOT soaked in a solution so it might be clean on the outside but I doubt the passages etc are clean .YOU CAN'T clean a carb by spraying **** from a can on it .
Might be different if you had the intake for your engine it wouldn't cost much to set it up and play with it a bit.

If you don't have knowledge on these old carbs and how to tune them it could be a very costly project that ends up laying under the bench .

Not trying to burst your bubble man but sell it back to the dude you bought it from and seek some help from the guys about some upgrades for what you have you will probably end up with more power and a much more dependable little car .

There are lots of guys on the forum that could guide you through some upgrades . Gerald m.

chillbro

I ordered the intake m today. Have a friend who has knowledge on this carb and has set carbs up on rotarys. So ill take a chance. I do have spare motors if worst comes to worst. Jus thought this could be fun. Thanks for your input guys.

fc323

Don't do it...carbs are for the weak, old, and mentaly frail.

Save it till you have a bridge or other big-*** port

RotaryEvolution

iTrader: (30)

probably go with 67 mains and 63 secondaries to start with. the V8 jets will be too large for a stock port 13B. stick with the 6.5 factory power valve and loosen up the accelerator pumps a tad so they have a tiny bit of slack before they engage.

the car will always have to be warmed up before driving it due to the lack of a choke, but if you set it up properly we're only talking a minute or 2 of idling with a warm idle setting of 1k.

the holleys aren't that bad to setup but they aren't great carbs for a real sports car like this. they are notorious for fuel starvation when cornering hard.

you can actually get more peak power from a carbed 13B over the stock intake system n/a setup due to the short and larger runners but as mentioned, bottom end suffers from the simple fact it is a carb and not very accurate or efficient at low speeds.