professor_speed

Rik JJ Had those Batten Dohc engines we talked about. At least that's what I've heard.

HabanaJoe

RIK - I believe they were the Batten B-4 heads on a "stock" style block, they had external belts and pulleys to drive the cams much like a Seatek diesel does.

The B-4 heads did not have the advantage thought to be gained. Long stroke engines do not do well with 4 valves unless the rpm's are way up there and a BB can not rev high enough to take advantage of these heads. That is why you see more small cui, short stroke engines with 4 valve heads, they respond better to them.

Rik

The BBC can rev very well, the current SC class in SBI limits the rev's to 7K but they can spin a lot faster than that and if there was a good OHC head the engines could rev higher and live a lot longer; not to mention the power increase due to the higher rpms also.

HabanaJoe

RIK - my comments were in regards to the 4 valve heads, a OHC head would help greatly it to rev higher you're correct. But with the long stroke of a BB the 4 valves offer no real advantage in natural aspirated engines, in fact the lower rpm power is diminished and 7,000 rpm's is getting into the range where they start to work.

Either way I agree with you it's time to get past push rods!

mike tkach

iTrader: (3)

mercury marine 1100 and 1350 have dual overhead cams and no pushrods ,i believe in the next 5 years,we will start to see more like them.

Rik

I agree, I think the overhead cams would be great for another obvious reason, that being it gets rid of the cam to crankshaft clearance which allows for different strokes. Also, I (not being an engine builder by any means) believe it will have less parasitic loss of power over the push rod design, but GM keeps trying to prove everyone wrong. One hell of a great head design probable goes a long way to make up for the push rod geometry; once again, what do I know but it certainly makes ignorant sense

I just cannot believe that no one over the years has made an OHC head for them. Here is a 4 valve head but not OHC. http://www.valleyhead.com/thunder.html

Kurt Hamilton

I have to agree Rik. Whilst I'm by no means an engineer with the ability to design something myself, in theory I can't understand why it hasn't been done yet (besides mercury only recently, and at a typical mercury inflated price). I can only assume head designers get so involved with re designing and improving what they already have that they don't think to go outside the box and design something that every other engine type has proven is superior!

T2x

They were engineered by Batten in Detroit. Batten created the "Quad 4" Oldsmobile engine and basically tricked up some aluminum heads off that concept. If memory serves...and it frequently doesn't...these were bolted to aluminum BBC style blocks. The motors with individual crash boxes were connected (one forward facing, one facing aft) through a "drop gear box" with "quick change" gear ratio options from 1:1 through 2:1. THis coupled to a single drive shaft per side running beneath the aft engine to a custom surface drive designed by Tom Wenstadt and built in Detroit. That drive train was awesome but the dependability of the motors was so bad as to be ludicrous. In most tests as you spooled up the motors and accelerated, you could see oil pressure dropping off on at least one or two motors to the point where the boat never achieved full throttle on more than two engines which, of course, were being held back by their counterparts. In its few races the motors were always detuned and limited to try and finish at least a few laps. In hindsight, Mercruiser 1000 SC's would have been a much better choice....or an engine development budget rivaling GM's to perfect an obviously embrionic concept.

Knot 4 Me

Ah, the Quad 4 engine. My wife had an '88 Olds Calais with that motor. Locked up sitting at a stop light with 7K miles on it. Next motor vibrated your teeth out at idle.

wannabe

Batten did a lot of work for Olds, Mopar, Chev, etc. They were an outside casting facility that could do jobs more quickly then internal operations which were geared to production.

Wannabe