stromberg head conversion

[scrapveiw]

I Think this chap has used his initiative , if you wanted to fit your own manifold and you have good machine skills , Omnitec or dave bean will not sell you the manifold on its own! Iknow i phoned them both to try and buy a manifold , no joy at all ,so fair play to anyone who has a go and succeeds , probably should get a few cast up and sell them in the uk .......

[rgh0]

I know two people who have done their own conversion and one who is part way through doing it. All these guys are very highly skilled fabricators and could do the majority of work themselves so labour cost was not an issue and they had access "free" to the needed machine tools so the cost was relatively small in direct cash but it took a large amount of their time.

These 3 are in addition to the poster that started this thread (and appears to have never completed the conversion and recently a milled off Stromberg head appeared on Ebay which may have been from there).

One took a set of carb flanges from an old scrap weber head and machined up some tubes and welded them to the base head where the Stromberg inlets had been machined off and matched the surface finish to the original head. This approach requires extremely skilled welding to avoid softening the head so is not easy to do. Unless you know in detail the shape of the original inlets you would not know it was a conversion. The end outcome is actually almost identical to the new SAS heads which have a similar inlet profile and size

One took a twin DCOE weber manifold from a cross flow and adapted it to bolt onto the milled off Stromberg Twin-cam base. This engine has not been run yet but will potentially face the cracking problems that John talks about

One is casting up the new inlets and I am not sure ,and I don't think he is yet also, how he is going to fix them to the milled off head.


Apart from first one that has done a fair few miles and performs extremely well I cant comment on the reliability or performance of the others yet as they have not been completed or run in cars for anytime. If your up to the challenge of one of these approaches or have other ideas then I encourage you to have a go. Just be aware it is not that easy to do!

The McCoy conversion is more than just mill off the Stromberg inlets and bolt on the weber inlets. The CNC porting that he does is also important to the power it produces and that is not easy for anyone to replicate but if your making a basic road motor I guess that does not matter so much. The details of his design is also important for long term reliability and is not easy to duplicate. I now have 3 of Johns head conversions and friends have bought about 5 or 6 more and they have all performed excellently. No connection just a satisfied customer

cheers
Rohan

[scrapveiw]

I can see what is done and how it is done if there is any doubt about other peoples machining skills . well here you go this is one of my creations , there are many people like me , what you see was scratch built , no plans and it runs like a watch, to be honest , i would fit the manifold in more or less exactly the same way as omnitec ,(a two angled joint on the flange) to maintain the strength of the head.I would try to avoid any welding if possible . I have welded lotus heads that have had large cracks from the valve seat to the water jacket that most people would throw in the bin , and also had them very hot to do this , Not realy had a problem with them warping if warmed up and cooled correctly.. To be honest some one has cornered the market and is trying to keep it that way ,I think if i were doing the conversions then i would probably not sell a manifold either for fear of being copied and gaining some unwanted competition I would be very interested to know who the chap is who is casting his own manifolds , if i could by one from him then it would save me a lot of work , i am only interested in a manifold for my self for my own car and i have no interest in doing it commercially , i have far too much other work to do an do not have time for another venture. the only reason i wanted a manifold from dave bean or omnitec is because i know that they work and most of the hard work has been done, not to copy .So if there is any one out there who can sell me a manifold i'd very much appreciate it.

[rgh0]

if you have the skills and time and like the challenge which it looks like you have then have a go... always room for some competition among suppliers I agree.

I have had twin cam heads that have had totally destroyed combustion chambers rebuilt when valves or rods let go, so much much more welding than just crack repair can be done without problem if you have the right welding techniques. I certainly don't have that level of welding skill but I know guys who do

So yes I agree you can satisfactorily do major welding on the heads if you know what your doing.

cheers
Rohan

[scrapveiw]

Rohan , who is the guy casting up his own manifolds? Do you think he would sell one ?

[rgh0]

Not sure if he intends to do more than just one for himself. I will leave it up to him if he wants to do more and sell them. I am sure at this stage he will want to finish the first one to see how it goes before he starts thinking about doing anymore for sale as either a completed unit or a manifold "kit"

The was one other conversion I am aware off which was sold by QED many years ago for a short period before they started casting new heads. This used a new cast manifold welded to the machined off Stromberg head.

cheers
Rohan