TR4/4A TR4A SU's replacing Strombergs....Linkage issues?

[karls59tr]

I have a rebuilt set of H6 SU's that I want to replace the Strombergs( of unknown condition) with. Will I be able to use the SU linkage for this swap? Are there any issues,modifications, or advice I should know about from those who have done this? Thanks Karl

 

[TR4nut]

Karl- If you are getting the SUs from a TR4A, are they HS6's? If so, those had a center pull arrangement which would not be compatible with the Stromberg setup. I think H6's though, would work.

 

[karls59tr]

H6's from a 3A. might just be a straight bolt on? Maybe I'll have to alter the choke setup.I'll put them on in the Spring and see what it looks like.

 

[trrdster2000]

Chock cable length will be an issue, the H6 comes from the bottom or viser versa and the linkage to operate the system is the stuff nightmares are made of, and the Stromberg, push rod is different. If you haven't already done it, run a split fuel line 1/4 inch around your choke cable near the fire wall to extent past the battery and use electric tape to wrap around the end of the fuel line. Fire from the cable hitting the battery.
Now my question is WHY???? Good Strombergs will give much less trouble, spend the time and money on two rebuild kits. I have gone the full route of H6,HS6 and Stromberg and have all setting on a shelf but the Zenith's.

Wayne

 

[Geo Hahn]

Will you also use the intake manifold from a 3A to fit up the H6s? Seem like H6s on a 4A manifold would be rather long/wide under the bonnet.

 

[karls59tr]

I was going to use the 4A intake with the H6's. There should be adequate room with the 3A pancake type filters. To answer Wayne's question about why not use the Strombergs I think there have been other threads discussing the pros and cons of that carburetor. I've just heard too many stories of people getting fed up with working on them because no matter what they do they end up running rich. I think I read on this forum about someone going to a car show and out of 10 TR6's everyone but one had switched to SU's. There I've opened Pandora's box now.

 

[Healey_Z]

There I've opened Pandora's box now.

Yea, car guys tend to be passionate about their carbs. Stromberg vs SU, Holley vs Edelbrock. (p.s. I'm an SU guy, but my Strombergs work just fine)

 

[trrdster2000]

Karls59tr, OK, now I'm a bit confused??? The thread was talking about TR4 swiping and you make reference to 10 TR6's, we are talking about 2 different type of Strombergs and I can see one but not the other. Why not go with the 2 inch jobs from a Volvo, because you have a set of rebuilt" doesn't mean you will be trouble free in the future.
I don't mean to unset your apple cart, but a little advise about other options.

Wayne

 

[karls59tr]

Don't get me wrong. I have a lot of respect for anyone that can successfully rebuild the whole range of Brit carbs. What were the problem areas,if any, with the TR6 Strombergs as compared to the earlier 4A ones?What were the changes between the two that caused problems or was it a lack of maintenance or knowledge that turned people off with these carbs?

 

[poolboy]

I do a little reconditioning of the ZS carbs, mostly the versions that the TR6 engines were equipped with.
Commonly, beside the leaks and wear, they are out of adjustment from an owner trying to compensate for an air leak or a Throttle Bypass Valve that needs servicing. Sometimes the metering needle has been lowered past the point of thread engagement with the adjuster.
There are a lot of screws exposed for a guy to fiddle with and usually does so on the so-called "Emission Carbs", CDSE and CD-2SE.
Throttle stop
Fast idle cam
Idle trim
Temperature compensator
Then on the later versions also:
Emission port transition adjustment screw
and some Throttle Bypass valve spring tension screws
All of which are exposed or are easily enough found by someome during the past decades.

 

[trrdster2000]

Well said Poolboy and of which the TR4 has very little of the above adjustments. In autocross I get some fuel starvation if I don;t set the floats a bit high on both carbs, but then that's a whole story in itself, setting up a car on a Sunday for 4 minutes of hard driving.

Wayne