Torque & HP Open Discussion

I emailed him about if he knows about BBC cams for counter rotation motors.

BuffaloBFN wrote: TRBenj wrote: I am almost positive that you can get an off-the-shelf reverse rotation flat tappet 454 cam for a reasonable price. Yes, the melling...not much else out there that I have found that suits our needs. Pro street/track (<--read high rpm's and lopey idle) are plentiful. I didn't price RR FT custom grinds. I bet there's been a few made though with the offshore crowd. TRBenj wrote: In the little research I've done, I believe they all used the gear drive like the PCM. Does 'all' mean 454's or boat engines? I think most BB's are chain driven(summit doesn't sell my setup), but I don't know enough to set you straight.

Greg, I meant that all RH BBC's used the gear drive. I havent heard of a RH that used the chain. I presume that all automotive (LH) set ups used the regular chain, though.

Did you ever find yourself a BBC cam expert? I have no idea what types of specs would be ideal for our application. Im aware that you dont want to go too extreme- but Im guessing you can be quite a bit more aggressive than the stock bumpstick... at least that was the case on my SBF with no ill effects. If comp sells the RH cam, then they can sell the blank. Whether you have them grind it or another shop handle that, it should be possible. I doubt its too expensive so long as you stay with flat tappet.

RH Fords (302 and 351w) do use chains. Everything rotates backwards except for the distributor- the gear is cut opposite to accomodate this.

If you read Buffalo's thread closely then youll notice that a 454 RH and LH cam are not the same even though they rotate in the same direction, as the firing order is very different (obviously).

Greg, that $2500 quote was for a custom ground reverse rotation ROLLER cam, correct? I believe that is the cause of the high $$$ amount, as Im guessing that no blanks currently exist for a roller RH BBC (just like nothing like that exists for a RH SBF). I have not called Comp or Crane to verify, but I am almost positive that you can get an off-the-shelf reverse rotation flat tappet 454 cam for a reasonable price. In the little research Ive done, I believe they all used the gear drive like the PCM. If the off-the-shelf RH FT cams exist, then the blanks exist... so a RH custom grind shouldnt be too tall an order.

The RH props that these boats turn are a thing of beauty. Whether you use a LH engine and the 1.23:1 tranny to reverse the direction or you build a RH engine in front of a 1:1, I think preserving the RH prop is important for the handling of these boats. The narrower boats are pretty weight sensitive, and all DD boats from the 2001 forward had their hulls designed with a RH prop in mind.

ya I've searched for the 454 and came up with your thread about your bowtie. I read most of it. A lot of good info. It was A LOT of reading if my memory serves me correctly.

I can't understand pcms whole thought process on a counter rotating motor.

81nautique wrote: Not bad I guess for Hammer and Chisel Guy right?

Huh? I thought you were a plate glass bender?!!?   

Is the cam/crank connection is on 351w a different set up (pardon my ignorance, I know nothing of a SBF except the 5.4l SOHC motor) than the 454? Basically does the 351w have a cam gear?

Just trying to figure out how people are getting cams from Cam Research for 250 for a counter rotation motor.

For 2500 ill start a 496 std rotation build (which is ultimately the long term goal a few years down the line)

it's a lot harder than that, I'm sure he well speak up and clue you in shortly.

81nautique wrote: Also, Seems this thread has become more about my motor than was intended so if anyone wants to add to the conversation please jump in. It was meant to be just a general engine hop up thread, not about me.

Alan,
Don't be so modest! You're one of the sites best "Hop up heads"

Brktracer wrote: Did anyone ever cut open a PCM exhaust riser?

Don't think there are any spare ones around, they don't rust out like the manifolds do.

JoeinNY- When you did your motor build did you price out a counter rotation crank?

81Nautique- I'm loving the motor build. What's your expected HP? are you going to re-prop? When changing to the CC heads do you need to change pistons to shape to the new heads or are you running stock pistons? I'm assuming from what you said about the heads being available in aluminum that you went with iron? What advantages does sticking with iron have over going with aluminum for boats?

Everyone- Does anone know what stock valve lift is for the PCM 454?

Thanks

you gain an inch Stiffler

eric lavine wrote: I keep thinking of the Mythbusters to where the truck with the tailgate down got worse mileage than the truck with the gate up, completely opposite of what was thought

Yep, that's because the pickup bed with the tailgate up created a perfect static vortex for the incoming air to flow over. I love that show.

Brktracer wrote: Alan, What diameter is the outlet on the HM manifolds (measured at the flange where the riser attaches)? Thanks, Matt

2.5"

Allen,Joe
   Goggle Silkolene 762 MX guys use it to seal the exhaust. I first saw it on Rolls-Royce jet exhaust flanges. I use it and it works - but
at $90 for a tooth paste tube it's pricy. A tube will last a life-time. I can send you guys a little in a plastic bag if you would like to try it.
    I think a 1/2 inch spacer would help the log type ex. manifolds.

JoeinNY wrote: For reference I did run the pcm manifolds with Ford Racing tall valve covers for a year, the fit was tight. On one side I could fit a piece of paper through without drag but not much more, on the other the paper would drag. Any spacer width would have made it enough to keep paint on both parts.

Maybe even double up on gaskets?