Single carb or double?

[Fletcher]

My motor.  Question: what is the performance difference between this and a dual carb setup?  Is it worth doing?  Is it hard to do?  Thanks!

 

Edited August 27, 2020 by Fletcher
Photo pasted as a link. Not the intent

[Stevenc22]

Dual carb motors can make more power. However if your motor hasn't been rebuilt and is tired, stick with a single carb.

 

Dual carbs are a real PITA since you have to tune everything twice and make sure they stay in sync. It is not for the faint of heart.

 

[AustrianVespaGuy]

If you mean dual sidedrafts, then unless that motor is on the stand with the intent of a rebuild, I would not recommend starting there.  My guess is it's instead ready to go into a car and get on the road, in which case:

Have you already rebuilt that stock carb? If so, just get driving.

If not, another option I would suggest considering is a 32/36 Weber.  Great carb on a stock engine, and I like 'em better than the stock Solex, though that may be just because I have more experience with them.

If you ARE indeed about to start on a rebuild, then we need to have a whole 'nother discussion, which may or may not include sidedrafts. . .

[rcf925]

In My opinion if you haven't upped compression, Ported head, Bigger cam theres probably no reason to go with dual carb set up, But if you do all the upgrading it's well worth it, After getting set up you shouldn't have to fiddle with carbs

[Fletcher]

Not doing a rebuild atm.  Engine/trans/etc was stored in doors while the car was out in a field.  It's just going back in.

 

[JerryC]

+1, put it back together as-is and figure out what you've got before fiddling with modifications. Do you know why the motor was removed?

Jerry

[Fletcher]

1 hour ago, JerryC said:

+1, put it back together as-is and figure out what you've got before fiddling with modifications. Do you know why the motor was removed?

Jerry

Hi Jerry,

 

I was told it was removed running when the car went in to storage.  The car was stored as a shell w/o engine, trans & driveshaft.  Those were all removed and stored inside.  The car was stored under tarps in a field.  The car is currently closer to you than me at Sonoma Raceway being reassembled before I get it. 

[73touring]

Single downdraft would be the way to go either the 32/36 weber or a 38/38.  The 32/36 jetting is very well documented and optimal for a standard M10.  A 38 will get more grunt low down but really won't make any more real power unless you've more squeeze. Plent of folks with tricked out 02s with a single 38 getting 140bhp same car might make 150 with with side drafts. Possible to get 180bhp (rally car spec) to max 225 bhp (Chevron race car if someone especially skilled (Lester Owen)  built it) but for a road car I'd get a 38/38 and spend the rest of the money on electronic ignition and suspension,  or a low ratio diff.

 

Best of luck. 

[zinz]

Buy a new 32/36 and replace all the rubber fuel line, both inside the trunk and the engine bay.  Use properly sized clamps!

 

When you remove the line off the fuel sending unit, you will find a white/yellowish plastic piece on the metal nipple.  It may be cracked...If it is cracked, remove it; then simply cut off a 1" section of the plastic line that goes through the passenger compartment and slip it onto the sending unit..

 

The new carb will get you going right off.  Go ahead and adjust the valves, replace the spark plugs, wires, cap, rotor, points, condenser... Give it the best chance to run with all the new components.  

 

Clean that engine within an inch of it's life while you have it out.... nothing worse than working on a greasy engine. 

 

Good luck with the project!

Ed