Discussion in 'Tomahawk Block Buildups' started by staged67gspwr, Oct 18, 2016.
Can you run a mech.fuel pump on a tomahawk block?
George, the fuel pump bolts to the timing chain cover, so it really has nothing to do with the block. As long as the cam has a fuel pump eccentric, you can run a mechanical pump. I'm very happy with the CV pump I got from Jim Weise.
Larry i heard thru some people that a mech pump wont fit or doesnt clear the cam because the block is very thick i just wanna verify this,i use same CV from weise
George, the fuel pump bolts to the timing chain cover (which fits the tomahawk block) The only thing I could see affecting the fuel pump would be a cam with bigger journals, but even then, the eccentric size is the determining factor on how the pump works. I know my roller cam has a bigger eccentric, but in my case, it worked great with the CV pump, Jim said it stroked the pump 100%. So again, the timing chain cover bolts to the block, the fuel pump is external to the block.
Larry im just going by what i heard i dont know thats why im asking,i was under the same assumption as you
George, I just looked at the TA catalog. There are 3 versions of the TA block, 2 of them have a raised cam position. I could see that affecting what you are asking. The standard stock cam position block should be fine, so it depends on what version of the block you plan on using.
yea maybe its for the 54mm cam tunnel you are right,im gonna ask TA to be sure thanks Larry!
The Ford size cam core from TA does not have a fuel pump eccentric, so you would have to have a Tomahawk block with the Buick cam size.
He has made a few of these blocks, but I don't know how many.. Call TA and ask.
Good, post what you learn, I'm curious about that as well.:TU:
Yup amen to that Larry
Jim you have any cranks you'd consider selling for future projects that are on hold or anything like that?
Sorry George, just the opposite..
Sitting here twiddling my thumbs on a couple builds, waiting for cranks..
This whole crank waiting thing sucks man why cant they stock some stuff,thanks jim
Jim,your CV Mechanical pump good enough for a big cube 555 or 560 engine?
George, this is what Jim had to say about the CV pump,
"The pump I use these days is made for a SBC, by CV products. These pumps use o-ring fittings, rather than pipe fittings, or inverted flare fittings, so volume is not compromised at the fitting, which is the typical bottleneck in mechanical pumps.
I have had great success with this pump, in 600 HP street cars, with a -8 input line, feeding from a fuel cell, or modified (enlarged) pickup in a stock tank. A -6 ouput line to the carb is plenty big. I have 3800lbs cars in the mid 10's with this combo.
I have also had sucess in 500 HP combos, with this pump, using the stock lines and pickup. I have run 4100lb cars in the 11's with this setup.
ON the dyno, at 6300 rpm, at 600 HP no more than 1 psi loss from base pressure was observed on numerous occassions. Granted, I don't have 14 feet of bent up fuel line on the dyno, but the saftey margin is certainly there.
On the roller cam motors, this pump fits perfectly, and strokes the pump nearly 100%, with just a change to the Buick arm. Stock flat tappet cams, with the smaller lobe, require a fair amount of porting to the housing, to allow adaquate pump stroke."
According to the specs, it is good for 850 HP.
I think Jim might advise using -10AN from the tank to pump, and -8AN from pump to carburetor if you were up around 800 HP. I have -8AN and -6AN. I have never had the car lay down on me at the track. You probably have the same set up I do.
Awesome Larry thank you buddy!!
Ya, thanks Larry, I only really get to check the board once a day here.. I appreciate your stepping up and filling in the details.
BTW.. the CV pump is good to 800 HP on methanol which is twice the volume of gasoline.. of course this is with big input and output lines.
Larry's -8 feed and -6 carb line is good for well into the 800 HP range.. the line way outflows the needle and seat assemby (s).