Mismatching Carbs?

[ShaneOC91]

Hey all, new to the forum but not to tuning.
I recently picked up my newest project, a 64 Rampside with a 95hp car motor swapped into it.
Got it running after some typical barn find TLC and rebuilding the carbs.
I noticed that for whatever reason, the driver's side carb has no adjustment screws. As if it only gets reference from the throttle rod that connects the two. I've balanced a few multi carb setups in my day and i've seen that on motorcycles but from what i understand, Vairs weren't set up like that.
My question is, was this typical of any year vair and do I need to swap out the left carb to match the right?

[terribleted]

Not sure what you are talking about. All primary Corvair carbs have 2 adjustment screws on each carb. They have an idle speed screw and a mixture screw. The carb cross shaft and linkage had 2 adjustable spots, one is the clevis on the accelerator cable where it connects to the cross shaft. The other linkage adjustment in the engine bay is an adjustable link from the cross shaft to the left carb. Balancing is achieved by disconnecting the left carb adjustable link from the cross shaft, (the adjusting clevis should be at the bottom not the top of this rod by the way), and while holding this rod up keeping the left carb against its idle speed screw reference the right carb at it idle using either vacuum gauge or Unisyn carb synch flow meter (easier IMO). Then reference the left carb and adjust its idle speed screw so it is at the same flow or vacuum as seen on the right carb. Last step is to rotate the left carb rod making it longer or shorter to cleanly enter the cross shaft and reattach it. balance is kept after this by always adjusted both carb idle speed screws the same amount if adjustments are made. If you have not adjustable rod on either carb you have wrong parts installed. if you have adjustable rod on the right side then parts might be swapped but when installed this way the rods will bind (unless of course they have been bent out of shape to not bind).

[ShaneOC91]

Thanks terribleted,
I did think it was absurd that one carb didn't have any idle or mixture screws.
Did some digging and looks like the previous owner frankensteined these carbs.
So far, I've determined that both have hats from 60 carbs, one is a secondary base, and the other is a base from a 62 or 63. Both however have 64 venturi clusters.
To say in the least, i have no clue what the last guy was thinking smacking these back together all weird.

[66vairguy]

T. Ted did a great job of explaining how to set up the proper carburetors.

I suspected you had a secondary carburetor on one side, but your description indicates both carburetors are "kludges". Sadly it's becoming all too common now.

If you don't have Bob Helt's Rochester book, then I strongly suggest getting it. Seth Emerson at Performance Corvair sells it now that Bob has passed. No book is perfect, but Bob did an good job and included some good illustrations.

The 64 carburetors were the most advanced on the EM engines. The 65 carburetors are considered the best with desirable features. The emissions control changes on 66-69 carburetors made them less tolerant of wear and internal passage corrosion.
The carburetors were changed almost EVERY year.

NOTE: is is very difficult to identity the year of the cluster for 64-69 carburetors. Just me, but your best bet is too find a good pair of 64 or 65 primaries (the 65 carburetors had an enrichment circuit to prevent a lean mixture under certain conditions - see Bob's book.

[ShaneOC91]

Thanks y'all.
I'm hunting down the book as we speak.
The block itself is from a car that either had no choke or a manual one as there's no provision for the automatic choke rod that I can see.

[terribleted]

Thanks terribleted,

To say in the least, i have no clue what the last guy was thinking smacking these back together all weird.

He had no clue either it seems.

[ShaneOC91]

Pretty much.
got a matching pair on order from Clark's so we should be in good shape.

[joelsplace]

If there are no provisions in the heads for chokes then the heads are '60 or '61 so it probably isn't a 95hp.

[terribleted]

Thanks y'all.
I'm hunting down the book as we speak.
The block itself is from a car that either had no choke or a manual one as there's no provision for the automatic choke rod that I can see.

The chokes are bimetallic coils mounted under the cylinder heads. There are small holes down through the heads right below the coke lever side of each carb. rods from the chokes come up thru the hole to connect to the carb choke levers. You should check and see exactly what engine you have. This involves checking the block code which is located right behind the fan shroud between it and the oil filter mounting casting (look straight down right behind the fan shroud). a 1 or 2 letter code should be there. that will tell you what the engine block was initially manufactured as. To really tell what it is you need to check the head numbers which are cast into the rear edge of the right head and front edge of the left (many heads have been swapped over the years). these 7 digits numbers and the block codes can be referenced in the first couple pages of the technical section of Clark's Corvair parts catalog.

[ShaneOC91]

To really tell what it is you need to check the head numbers which are cast into the rear edge of the right head and front edge of the left (many heads have been swapped over the years). these 7 digits numbers and the block codes can be referenced in the first couple pages of the technical section of Clark's Corvair parts catalog.

Yeah I know my head numbers indicate a 1960 80hp motor.

[66vairguy]

Shane - I going to assume you have a manual transmission. If it's a PG then disregard the following.

I don't want to rain on your parade, but you may get to the point you want to go with a different engine. Beginning in 64 the engine was larger and that means the crankshaft was changed and the engineers revised the flywheel and bellhousing to eliminate a problem with the clutch being "reluctant" to engage at high RPM. As the HP numbers increased so did the maximum RPM and that's when the clutch geometry issue was discovered. Anyway ---- if you start thinking about going with the larger engine you should look at what transaxle, bellhousing, flywheel you have.