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TR4/4A Convert from H6 and log to HS6 and 4A intake

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TRMark

TRMark

Jedi Knight
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My H6's need an overhaul, I have a 4A intake on hand (no idea where it came from). I have heard the HS6 with the longer 4A manifold works better than the H6 and the log style. Problem is the parts needed for the center pull throttle and different choke system. Is it worth making the effort? If I want to proceed anybody have the linkage parts?
 
I really doubt it is worth the effort and cost. First the linkage is RARE. I am running two TR4's and both have the HS6 carbs. About the only real advantage that I see is not having the grommet / seals at the float bowl attachment. I have not seen any performance improvement.
Back to the linkage. On one of my cars I am using a modified TR6 linkage for the long piece and the center base piece. That center base piece is the ultra rare piece. Oh yes one more disadvantage is the center pull linkage is very difficult to work on/ adjust.
Charley
 
After you mentioned about the linkage, I looked at some diagrams and pictures, what a mess, I figured I'd have to make some changes, but. There has got to be a better way, maybe I can change out to a cable. The reason for the concern over flow is I would like to install a more aggressive cam, everything I have read says the later manifold and HS work much better.
 
Couple of things I would give some thought too. Early Strombergs on the 4A manifold, they perform very well. Use a Spitfire accelerator pedal and cable for a GT6. You will have to drill a couple of holes in the firewall for the pedal and make a bracket or get one off a donor for the spring part at the carbs. Much smoother.

Wayne
 
I don't know if this will help, but I did something similar. My TR-3a has the small port 4a head on it. It had the large port 3a log intake when I got it, so I put a small port 4a intake on it. I also have the H6 carbs (2nd pic). Initially, I used my TR-3a throttle linkage but the added manifold length caused it to bind. I ended up using a cable and attaching it to the center shaft that connects the carbs. I moved the throttle linkage that was on the fwd carb onto the center shaft (1st pic). It connects to the cable. The fixed end of the cable connects the air cleaners (3rd pic) and it is adjustable. The cable is a hot rod piece from Lokar. I think RATCO sells a similar setup for the TR-6 that can be adapted to a TR-4. Here are a couple of pics:

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I cant help with the choke.

Good luck,

Roy
 

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Thanks for the pics, Roy. I think maybe a cable, Ratco or Spit and some shop made parts might do it. I also studied the linkage used in TR7 when converting to HS carbs. Hadn't thought about using the Strombergs, I heard the needle selection is limited. I am going to help a friend with a TR6 tomorrow, I will look at the linkage and Bergs.
 
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