i have a 71 f-250. I want to build a tug boat fe to put in it. Currently has 390 (love it) and want more. Perhaps 410 or scat 390 stroker. Looking for tons of torque. Any suggestions (cam/stroke).
Thank you,
kapp 4x4
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i have a 71 f-250. I want to build a tug boat fe to put in it. Currently has 390 (love it) and want more. Perhaps 410 or scat 390 stroker. Looking for tons of torque. Any suggestions (cam/stroke).
Thank you,
kapp 4x4
Here's your 445 cubic inch stroker kit, but 11.14:1 is a little stout for pump gas on the street.
http://www.speedomotive.com/fe_ford_...id_stroker.htm
Make a deal with Speed-O-Motive to supply forged pistons with a little dish to them or even KB hyperuetectics with their "D" shaped dish (better for squish than a round dish) to bring the compression down to around 10.0:1 or 10.5:1, zero deck the block and use a head gasket with a compressed thickness of 0.040" to 0.045", then use this cam or something similar....
http://www.cranecams.com/?show=brows...Type=camshaft.
Use Edelbrock Performer dual plane intake and 850 cfm carb. If automatic, use a 2,500-2,800 stall converter. Rear gears in the 3.70 range would work well. Save up a little extra money to pay for tickets.
Others on this board may have alternate combinations to suggest that may work as well or better, this is just the way I see it.
bump
also be forwarned the stock dana 60 is not stout enough for pulling ya need a dana 70 or a gm corprate upgrade your u joints too
Sounds like chappy has "been there, done that":)
http://www.cranecams.com/?show=brows...tType=camshaft is a good choice for what you want - the tugboat deal. The old stock 390GT cam made a lot of torque, but Ford seems to have dropped it. Lunati makes a decent replica, product LUN-10503 at Summit Racing.
For heavy loads, getting the compression down will probably be really important to you, but the challenge is not to drop it too low. I liked Tech's take on it.
Question for Tech on the carb: My stock 428CJ runs a Holley 735 (stock carb), and pulls hard to the top of the cam - about 5800. The math works out, but you're recommending a bigger carb. I know a friend with a 327 SBC went with the 850 mech secondary double pumper, and swears it helped, but the math tells me it's overcarbureted. Any explanation would be really enlightening - there's a lot I don't know, and this is one of 'em. **)
been there done that got the t-shirt tech. the hi-boy's ran a small design of u joint i upgraded to a gm corprate rear transfer yoke off a gm and a 4 1/2 rear driveshaft SPICER BLUE joints is the only way to go but i have heard that borg warner has sold the spicer line so i guess we are all up in the air on joints also take the spacers out from between the springs and rearend and the small 1" spacer from between the springs.reduce the front spring pack to one main leaf good shocks 33" trxus super swamper all-terrains and you'll have your driveline taken care of. now start behind the drivers door to about 3' back boxing the frame this is where these frames like to bow and this will take care of that. slipper clutch you will not regret it you will go through hundreds of regular clutches vs. one slipper ( sintered iron ) ram makes a good twin disk one. now you are nearly bullit proof build as many ponies as you can afford once the truck is set up and see what she'll do good luck and never get angry cause you didn't win but be happy that you are able to try
Posted by SnakeHerder:
"the math tells me it's overcarbureted."
Yep, I agree, for instance:
A 355 Chevy winding 6,500 will show needing 668 cfm @ 100% volumetric efficiency, but if you have a decent cam in it and don't bolt a 750 carb on it, you're messin' up.
The only explanation I can come up with is that with good heads and a good cam, you're pulling an efficiency above 100%. The 750 carb example above works out to 112%.
If you think about it, it makes sense that efficiency is higher than you might think. With a long cam, the intake stays open longer, way past bottom dead center, so that you have more time to pack the cylinder. The gas slug has inertia and so probably packs the cylinder in excess of 100%.
????????????????:)
Well, turns out my 390 is a 410. Perhaps why I was so happy with it. When I first bought the truck I was told it had a 390. Suppose the joke is on him.
Shortly after buying the rig, I swapped out the stock heads and intake 2bbl (not sure what they were) for a set of rebuilt C8AE-H heads and edelbrock performer intake. Also Edelbrock (carter) 750 carb, headers, dual 2 1/2" exhaust. It ran very well for 2 years but now smokes very bad. Bottom end never rebuilt w/ stock cam (dont know what it is)
I would like to rebuild stronger. Going to bore +30 and keep 1U crank for a 416 I believe. What comp. ratio should I look for. Suggestions on pistons? Would a performer RPM intake be advantageous or will it exceed my RPM range for a higher torque motor. Also heard a higher lift/shorter duration cam would yield best torque. Is this true?
Thanks, kapp
Kapp, does it smoke all the time, or on start-up? My 428 smoked on start-up, but it quit smoking as it ran, and it turned out to be the valve stem seals. That was in about 1977...Quote:
Originally posted by kapp714x4fe
Well, turns out my 390 is a 410. Perhaps why I was so happy with it. When I first bought the truck I was told it had a 390. Suppose the joke is on him.
Shortly after buying the rig, I swapped out the stock heads and intake 2bbl (not sure what they were) for a set of rebuilt C8AE-H heads and edelbrock performer intake. Also Edelbrock (carter) 750 carb, headers, dual 2 1/2" exhaust. It ran very well for 2 years but now smokes very bad. Bottom end never rebuilt w/ stock cam (dont know what it is)
I would like to rebuild stronger. Going to bore +30 and keep 1U crank for a 416 I believe. What comp. ratio should I look for. Suggestions on pistons? Would a performer RPM intake be advantageous or will it exceed my RPM range for a higher torque motor. Also heard a higher lift/shorter duration cam would yield best torque. Is this true?
Thanks, kapp
Really great about the crank! It's good material, and the C8AH-H heads could be pretty good. They made a number of varieties on that casting - send me a private message or email or something and I'll look at what I've got on 'em when I get home.
Don't do too much (any) port work on the heads if you want bottom-end torque. The heads flow pretty well to start with (though I understand there's some machining you can do to make them flow well without opening them to the point that they have to flow lots of air - to do with the Thermactor connections if memory serves).
As far as cam, I'd have to look. The ones I listed above are largely compatible with the 390GT and 428CJ (same cam). The Lunati was the closest match.
Sounds like we're working on similar projects, though I want mine to lope and work as a drag racer, so I'm working on the 2500-6500 RPM range, C-6, and so on. I'll probably go with the Comp Cams version - if I'm remembering right, it was better for higher RPM.
Like Tech talks about, you can get more through the motor than the formulas tell you (even the ones on the Holley website). But you're probably looking for no more than 5000RPM, so the 750 would likely work well. I'm running the stock 735 on the 428CJ, and it pulls good into the 5800 range, so 750 gives you some headroom. (Don't have the formulas with me - I'm using my business PC, sitting in a hotel room in Dallas, trying to get tired enough to sleep).
I look forward to seeing what comes of this.
Tech, thanks. I was of the impression you needed pressure induction (turbo, blower) to get past 100%, but headers and enough overlap will help with the charge velocity, and the good heads no doubt help. He's got the angle-plug bow-tie heads that were the hot ticket in 1977, and did a lot of port work on them.
The 428 seems to work out about as it should. It sort of runs out at 5800 with the 735 Holley, and that worked out to about what it needed. Sounds like I need to go bigger on the cammed up 410 (+.060). I keep saying there's as much art as science to this.