So, I am currently looking to purchase these heads from Kevin (rhodyguy).

http://www.914world.com/bbs2/index.php?showtopic=241564

I would like larger valves and these are definitely large 48x38 according to Kevin. Are these too big for the street? I need some opinions as to what/how you would use these. I am aware that very large valves are not always the best for a street performer, but okay on the track. I will never be racing the car. I am assembling parts to build at least a 2.1L/2.2L with dual carbs.

Thats a great deall for 2.0 3 stud heads. Kevin won't steer you wrong.

John

I am sure that an engine guy can give you a better answer but I was always taught that any increase in flow was a good thing. Even putting headers can gain you a few HP. These heads are bound to add up to a number of HP.

Wish I had the bucks to buy. I have purchased from Kevin and he won't sell crap.

I agree, the heads look good and are well priced. I just need some advice on how to best use them.

Not sure I follow "how to use them." Having higher flow heads opens a few doors. You can take full advantage of more aggressive cam grinds, get more air and gas into your larger displacement P/Cs, and have the ability to feed a longer stroke cam. I am sure there are others I don't know about.

But if you are building a street able, car it would seem that matching the right cam, exhaust, and carb setup would take full advantage of the heads. I have no data to say how much of an increase could be gained but it certainly be a kick in the backside.

Some of the engine builders can give you a more detailed description of what can be done and the likely out come in relation HP.

IIRC, Mr. Raby is not a fan of the 48mm intakes. First, they are (relatively) heavy, so harder to control. Second, they tend to kill velocity at anything but very high flow rates (e.g., high RPMs). Third, the exhaust is where the Type IV heads need the most help, so you wind up addressing the wrong side of things when you put very large intake valves in.

That said, I am not an engine build guru--and I may be misremembering things.

--DD