Torque & HP Open Discussion

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

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)

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

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

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.

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.

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.

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

General question related to torque...does anyone know if the python 502 or used rectangular or oval intake ports?

Here's a link to the controller I'm using. I think this is the same one Matt mentioned he has.

Alan - Your engine is a work of art!

I had that rubber smell/smoke when I replaced the hose after my manifold repair. It was gone after a few outings.

Pulled the water feed to the elbow and started the engine briefly, plenty of water out the hose. Then pulled the elbow itself and hooked it up to the tap.

From the side it appears plenty of water right?


But looking from the rear you can see how the water circulates around and dumps out the bottom only.


The hose was quite a bit hotter on the top than the bottom and this photo confirms my thoughts. I believe I'm just going to have a stainless steel 3" elbow made to go from the manifold elbow all the way back to the mufflers and eliminat as much rubber hose as I can.

Anybody have any thoughts or experience with these manifolds, they are similar in design to commanders and I don't recall hearing of any cooling issues with those. JoeinNY/Trbenj,etc..comments? Thanks

p/allen wrote: Can you block off a portion of the bottom part so it will be redirected to the top part of the outlet. Does the hose from the front cool the manifold and dump out the top of it . Is the inlet you are testing the extra water from the rwp . that doesnt go through the engine ?

Pat, in this photo you can see where the water comes in the front top of the log, circulates down the length of the manifold then comes out the front bottom and is directed to the elbow via flexible hose and out the exhaust.

Alan,
I have to assume that the elbow has only 1 water jacket. How many water ports are there from the jacket into the exhaust? Getting the water into the exhaust through another port I can't imagine would make much of a difference. The exhaust flow should be blasting the water all over in there?

Alan,
In the land downunder we do not seem to use the concept of the rubber hose straight onto the back of the exhaust manifold. Even our very early ski boats used SS S-bends and then the rubber hose after that. Normally the water exit tube is in the S-bends but a bit lower so there is less chance of water misting getting back into the engine.
Even though your US boats were light years ahead of our locally made boats until the last few years. I feel this is one area where our boats were better.

The bends below are just for info the freight costs from AUS would make them uncompetitive. They are mandrel bent so they flow very well.

The alloy log manifold may be a option for some US based wanting log style manifolds. I always planned on going the Hi-tek path in the future but these are very well priced. I will try and get hold of a set and investigate more.

Looking forward to your opinion after the water test. On the performance gains you have achieved with these modifications

S-Bends

Alloy Log Exhaust Manifolds