Dual carb throttle linkage

Hi, I have a type 4 engine in my Puma and have accumulated a bunch of parts for the type 4 engines. I have both a cable throttle setup  called the sync link and a CSP bell crank type throttle linkage system that uses a bell crank and arms to open the carbs. I had the same issue as you using short intake manifolds and having a type 4 setup. Call me if you are interested in buying one of the two throttle setups I have. I like the bell crank set up the best I had it shipped from CSP in Germany. It gives smooth and completely even opening of both carbs all the way from idle to full open. The CSP bell crank system is shown in the first pic and it mounts at the rear and will work with your Porsche fan setup and should be your best option. The sync link will need a cable to go to the front of the fan housing. I will sell you either of the two I have as they are both extra parts for me. Call Jim 812-972-4516 Here is a link to the csp linkage I have new in the box never used Bellcrank Linkage CSP :: Custom & Speed Parts (CSP) (csp-shop.com)

x2 on the CSP bell crank system.  Mine was mounted on the rear side of the shroud, opposite from Jimmy's, but it worked very well.  A lot of folks like the Sync-Link as well.

Mine is on the rear of my shroud as well. Look again.

I was using front and rear like the ends of the car.  What I meant was mine is toward the rear of the car.

  The type 1 versions of this usually are on the front of the engine which would be the rear of the Speedster.

Thanks Jimmy!!! looks like the CSP system is the answer!!!

@Jimmy V. posted:

  The type 1 versions of this usually are on the front of the engine which would be the rear of the Speedster.

So Jim, what are you using on your Type IV if you’re will to sell both of these? Not in the market, just interested.

I am using the Vintage speed bellcrank linkage it is similar to the CSP one but much more refined and much smoother in my opinion.

I recently switched from CSP to Vintage Speed linkage.

The twist-style bellcrank linkages can be mounted on whatever end of the engine gives the clearance for them to work, as can be the Sync-link.

If the OP, @Gary Hafner indeed has the 911-style shroud and SHORT type4 manifolds, that indeed can be tricky to get the linkage to clear.

I got a CB hexbar linkage to fit a type1 on the pulley/alternator side to JUST fit even using a Berg 356-style breather tower on top the alternator stand. It JUST fits. According to either Berg or CB(can't remember which), it won't fit.

Look in the archives for "Turning that carbs around". I have a fix for the hex bar linkage but the best part is by turning the carbs around you have access to the adjustment screws and idle jets.

Nice, Jim. I had my carbs mounted that way on my type1(now CB 48mm throttle-bodies). The manifolds were, and still are, CB Space Savers which do indeed put the adjustment screws and jets on the inside.

Nice in a Spyder(saves you from upper frame rail interference), but REALLY nice in a Speedster engine bay.

If you turn the carbs around, sometimes you can fit everything by actuating the throttle levers from the other end of the carbs.

All these pictures are GREAT references for what can be done to get it to work.

The OP needs a linkage that works with short type4 manifolds and a Porsche shroud(although I'm not sure exactly which shroud that is). Fitment can be done but he'll have to experiment.

Here's my EFI Spyder, heim-jointed CB Performance space-saver hexbar on a type1:

I've changed the air filters and breather arrangement since. No more hoses to the carb top.

@DannyP, are those the CB turbo hats?  I always thought they would be good to plumb to a single, large air filter. Less chance of a carb fire if the engine backfires.

Yes. I used them for noise reduction with the top up. That worked a treat, took the edge off the noise for sure.

Just remember, every single change in one place affects something else. The shorter "turbo hats" made the velocity stacks too close to the inside of the hats, the hats are about a 1/2" shorter than regular air cleaners. So I got shorter velocity stacks. That affected the powerband very slightly, but not enough to really notice.

The kicker was when I added "Jet Doctors". The Jet Doctors were very close to the upper edge of the shorter velocity stacks. This caused a MAJOR rich condition when the carbs were in transition, right around 2000-2800 rpm. Like fall-on-it's-face undrivable. Verified with a wideband O2 sensor going full rich during transition.

How did I fix the problem? Removed the short velocity stacks, installed the original tall ones and swapped the air filters back to the regular style. The transition issue completely disappeared.

I believe that the idle air was affected by the intake air resonating around the torque peak, which you can see and hear with the air cleaners off. This is due to large valve openings and intake and exhaust overlap: both slightly open at the same time.

This doesn't happen at all with the EFI.

Sorry for the thread drift, folks.

Danny...no apologies necessary for the "drift"...will be looking into bigger air filter and adding stacks now that I will have some "head" room with carbs.  I assume a built FAT 2.8 L type lV will need more air than stock filters area can provide...so hopefully there will be enough room to add some velocity stacks and a larger dune buggy type filter.  How big is your engine?  I have big Dels. Haven't heard of the jet doctors?  Do you still find them useful? with stock type filters?

Sure this is/will be a hot topic...hope you...and others can save me some time and money

Jet doctors..I haven't had any trash in my carburetors since they were installed. I made mine from 1/6" brass tube available at hobby shops.

@Gary Hafner I have a 2165cc type1.

I had 44 IDF Webers, and yes, the Jet Doctors worked. Although I had far less problems than most, I don't recall any plugged idle jets once I installed them. They are sold for both Webers and Dellortos.

The stock height air cleaners are fine for a 2165cc, I believe they are 3.25" tall. Most standard velocity stacks are 2". There is plenty of clearance for good flow.

I would get taller filters if the engine builder specifies taller stacks.

I've swapped over to 48mm throttle bodies and I'm running EFI now.

Exactly; the CB Performance hex linkage just fits when using the Gene Berg breather. Not much more room for error.