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Spitfire Anyone have a HS6 on their spit

tomkatb

Senior Member
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I have a recently rebuilt 1500 spit. I dislike the 150 carb on it very much. Has anyone installed a modified intake with a HS6 on their car?
 
I had HS2's and then HS4's on my 1500 ( it had a webber when i bought it ) HS6's might be a bit too much for a stock 1500. Gas flow the head, high lift cam and a nice big exhaust and then you might be ok.
What ever you do, you will be much happier when you ditch that single Stromberg.
 
I bought a Euro SU dual HS4 on eBay that just arrived for the Spit. I haven't installed it yet, but I'm planning on installing it next week.

I'll take a bunch of pictures and send them along if you want....
 
I have not personally done this, though I know some who have. John Kipping most notable. Claimed results were comperable to the dual SU's up to about 5000 rpm. Beyond that flow loss became noticable.

Beware that the Spitfire ZS manifolds come in two primary flavors, small and large runner. You will get poorer results should you attempt to fit up the HS6 to the small runner manifold.

One other caviat to consider with the Spitfire 1500 ZS manifold is that the cross runner is smaller than the 1.75 throat of an HS6. When you modify the manifold to fit up the HS6, you're going to be necking down a bit. The HS6 will also have to sit low on the manifold because of the way the cross runner isn't centered.

Some other Triumph of unrecalled name utilized the 1500 with a manifold specifically designed for the HS6, but was redrilled and mounted a CD150 ZS instead.

If you're still with me, this manifold type may be significant in that this other manifold is what John Kipping used with his HS6. He did not modify a Spitfire 1500 manifold, as I recall.
 
I had an HS4 on my 1500 Spridget when it was a street car. The engine is the same as your Spit. I was very happy with it. All I had to do was "slot" the holes in the carb to fit it onto the manifold (using a rat-tail file). It matches up to the manifold opening pretty nicely.
I also filed off a small locating tab so that the fuel bowl could sit level. All in all, very simple and it ran great.
My HS4 came from a Volvo. These carbs are pretty easy to come by.
Right now, my 1500 has an S&S race carb on it, but I am planning on putting this engine back in a street car (the racer is getting a 1275 Sprite engine so it will be vintage-legal). When the 1500 is returned to street-use, I'm putting the HS4 back on.

HS4 (manifold side)
Img0402.JPG
 
Foxtrapper you are correct. The Triumph that JK was talking about was, I believe, a Toledo. It has larger runners and would take the H6. I've been looking for one, but I guess I will have to try the UK. John says it is almost as good as the twin HS4 intake, but with a lot less hassle.

BTW, I have noticed John doesn't post much on yahoogroups any more. Konw why?

Another tidbit...Do you recall JK saying that the Triumph 1500 engine was sent to Israel in a mitary vehicle that had a light weight crank? It didn't suffer the problems of the others in regards to bearings.
 
Thanks for the responses.

I know where I can get a ported manifold with a rebuilt HS6 reasonably. I thought it might be simpler. As the air flow rate is near a set of HS2’s. It might be a good choice for a close to factory 1500 rebuild.

I only changed the compression some, balanced it much better, had the head shaved a bit and installed an aluminum flywheel.

It idles at less than 500 rpm now, but seems starved at 4000 rpm

Larry
 
Larry, due to rules restrictions, I was limited to a single HS4 on the 1500 Spit I was racing. It was plenty of carb for 140 HP, and bolted right up to the existing ZS manifold.
Jeff
 
billspit said:
BTW, I have noticed John doesn't post much on yahoogroups any more. Konw why?

Another tidbit...Do you recall JK saying that the Triumph 1500 engine was sent to Israel in a mitary vehicle that had a light weight crank? It didn't suffer the problems of the others in regards to bearings.


John apparently has found a new business initiative and is selling some sort of geothermal heating systems or so he told us on the Herald group when he surface a few months back. Apparently keeping quite busy.

As for the 1500 with a lightweight crank, I sort of doubt it, I haven't seen anything in the military which is lightweight! Seriously, I have a sort of friend whose father used to own the biggest service station for Triumph's in the north part of the county. Back when triumphs were common they serviced all the military triumphs in the north. I will check with him, but of the triumph engines used by the army, almost all of them were in cheap locally assembled cars based on the Herald running gear (even had a Triumph steering wheel) These definitely didn't get a special version of the engine! The only "military" product was the "dragon" (also known as the Pony) a 4x4 based on the 1300 fwd converted to 4x4. The volume of this was so low that it is hard to believe that Triumph would have invested money designing a special crank for it. In any case any there don't seem to be any of those left. I have been looking!
Yisrael
 
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