R&D cast Head questions

[Dmart29]

Hey guys I picked up a used SJ last summer that came with a few extra goodies, one being a R&D cast head. My question is (pics to follow) this head has o-rings and built in domes, it almost looks like a gasket had been installed as well, is this a o-ring / gasket sealed head? I’m also wondering what size domes these would be. The ski came with an almost brand new SBT Motor with warranty so I haven’t popped the head off (planning too in a couple weeks when I’m back from work). If anyone has info and would like to share that would be great, can’t find much online!

 

[Big Kahuna]

I think you use a sealant along with the orings. It has been almost 20 years since I ran one.

 

[Harbor]

I ran those heads, ^^^ yes an oring seals the combustion chamber and 1211 silicon seals the outer perimeter water jacket. It brought compression to around 185/190.

 

[Dmart29]

I ran those heads, ^^^ yes an oring seals the combustion chamber and 1211 silicon seals the outer perimeter water jacket. It brought compression to around 185/190.

I ran those heads, ^^^ yes an oring seals the combustion chamber and 1211 silicon seals the outer perimeter water jacket. It brought compression to around 185/190.

What about cooling on this head, do the cooling lines hook up the same as the stock head? Is dual cooling possible with it? I’m from BC the Okanagan lake gets pretty warm in the midst of summer

 

[Harbor]

It only has one threaded bung for cooling. I ran dual parallel cooling, so one line fed the engine and one fed the exhaust. It put out a lot of cool water from pissers.

You could have a bung added. My fab guy would prolly charge about $40 to add another bung.

 

[Roseand]

I ran an Oem 701 head with dual cooling a few years back. Just tapped the opposite side water jacket, didn't weld on any extra material. Zero issues. Im guessing this head might have some material to do it that way too

 

[Dmart29]

I ran an Oem 701 head with dual cooling a few years back. Just tapped the opposite side water jacket, didn't weld on any extra material. Zero issues. Im guessing this head might have some material to do it that way too

So you just mirrored the opposite side of the head basically? Did you have to do any minor tuning of the B-pipe for for correct temp when you add dual cooling? Also spark plugs - what did you guys run

Thanks!

 

[Harbor]

Ran br8ES, long threaded plug. Not short HS plugs, just make sure it has deep threads in head.

Looked at some old picks on mine and it sorta looks like the bosses on the other side of the head where machined shorter. Like those on that side where milled off and one used as the bung fir a second water fitting. You might have a look at yours and see if that could work?

If fab work isn't an option, You could cut off one bung yourself with a cut off wheel and square up flat and carefully drill to water jacket, carefully..