255 stroker???
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From: East Bernstadt, Ky
255 stroker???
hey guys i have an 81 f100 with a 255 4.2. i know this motor is not the best for performance but i want to stick with the original one so switch it with a 302 or 351 is not an option. does anyone know of any performance upgrades i can do while i am rebuilding this motor? since it is basicly a 302 with a smaller bore can i use a 302 stroker kit minus the pistons. also is there any other heads i can use to increase the poor flow. Any suggestions to help the performance of this motor would be great.
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From: Southern California
For stroker info- I would call HTC (Hank the Crank) in SoCal- they have been building strokers longer than anyone else
For cams/valvetrain, I would call Iskenderian (ISKY) Racing Cams (SoCal)
For cams/valvetrain, I would call Iskenderian (ISKY) Racing Cams (SoCal)
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northernautoparts.com has a rebuild kit for the 255 and it looks like you can get .030 over pistons from them as well. Thats about your only option is to stick with 255 parts. The bore is 3.68 and to open it up to for the 260 pistons you will have to bore .120 and for 289-302 pistons it will be .320. It does share the same stroke as a 302 though.
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From: jeffersonville, IN
255
I'm pretty happy with performance of my stock 255 in a 4200 lb vehicle with a c4 and 3.25:1 differential. I've got a weind 4 bbl intake, holley 360 cfm 4bbl, dual 2" exhaust on stocker manifolds, no catalytic converters, 1964 mustang 289 distributor with vacuum advance, pertronix coil 8mm wires .040 spark gap. No egr. I do have the vacuum advance and PCV flow delayed by the ported vacuum switches until the engine warms up. Rest of 50 vacuum hoses are eliminated. No EGR. This setup accelerates better in traffic and has better economy than a 5.0 I took out with same intake and exhaust. The 5.0 had the wrong cam for a carburator and a heavy vehicle. Its no racer, but I am keeping up with traffic and I'm getting 14-19 mpg compared to 6-8 mpg onthe 5.0 engine. This engine has got to be putting out way more than 115 hp. I've driven the same car with a 292, 2bbl, single exhaust, 3 on the tree and 3.56 rear, and it feels about the same now.
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Joined: May 2007
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From: British Columbia
The small 4 barrel carb and dual exhaust are probably the best upgrades you can readily do. I'm curious about your intake manifold. Can you post a picture of it, or describe it? Is it a Ford piece? If aftermarket, what make? Are your heads stock 255 pieces?
I didn't know there was a 4V intake available for the 255, as it has unique oval intake ports, and has an open "spider type" intake manifold, requiring the use of a bathtub style intake manifold gasket, right?
I didn't know there was a 4V intake available for the 255, as it has unique oval intake ports, and has an open "spider type" intake manifold, requiring the use of a bathtub style intake manifold gasket, right?
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hey guys i have an 81 f100 with a 255 4.2. i know this motor is not the best for performance but i want to stick with the original one so switch it with a 302 or 351 is not an option. does anyone know of any performance upgrades i can do while i am rebuilding this motor? since it is basicly a 302 with a smaller bore can i use a 302 stroker kit minus the pistons. also is there any other heads i can use to increase the poor flow. Any suggestions to help the performance of this motor would be great.
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From: East Bernstadt, Ky
Yea I got real exited when I read there is a 4bbl intake for these. As for the stroker i was thinking that since the crank was the same as the 302 just hollowed out that I could get a crank from a 351 and have it milled down to the right size. Or maybe I'm missin something big that would keep it from working. I assume he is talking about a weiand intake. I looked through the website and couldt find it. So if you remember where you got that from or want to sell yours please let me know.
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351 crank = 3.50 stroke. 347s use a 3.40, so I am guessing 3.50 is a no-go in that block, especially with the smaller bores. That would be the long way around anyway. Check with Scat or other fine brand stroker crank seller. Rods needed too, and pistons, and maybe heads, and of course the manifold..... Ready to pop for a 302 or 351 yet?
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From: East Bernstadt, Ky
would be nice to have all the aftermarket options but I'm gonna try to stick with the original 255. I might just keep the crank and pistons/rods the same and just work with the cam. I know they are the same as the 302 and will probably just upgrade to a roller cam,lifters and rocker arms. Doing that along with porting and polishing the heads and intake should help me out quite a bit and help the rebuild get maybe an extra 100k worth of use.
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I understand the thinking here and can't disagree with it--you've got a servicable engine, make the best of it. BUT, before you spend much money, compare at every step the alternative of a 302, maybe the 351. Value for your money is what I'm driving at.
Good luck with it. No posts on that 4v manifold yet....
Good luck with it. No posts on that 4v manifold yet....
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From: East Bernstadt, Ky
yea i believe you would have to chase down the easter bunny to get an after-market intake for these. And on the 302 I am starting to consider a swap just need to see what I can find a good one to rebuild for. I would really like to have one of the nice ones out of the summit magazine with the 4 bolt main bearing retainers (I know they have a different name but its late) but they are pretty pricey
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From: jeffersonville, IN
4bbl manifold
Appreciate the interest, the Weiand is a holley brand, pn 8011, it is a 302 part and the intake runners do not match. It doesn't matter, I'm still getting 18 mpg and I outdrug a 7.3 PowerStroke ambulance (350 van) out of a stoplight yesterday: he had to back off and go behind me to get on the freeway. I went to a 4bbl because the RFGas they sell here runs through a stocker 2bbl like water, fouls plugs in weeks, stinks, huge hydrocarbon emissions, and I can't get small jets for a fomoco carb. Edelbrock carbs are easier to tune than the holley 0-8007 360 cfm, but the mainshaft locked wide open on my edelbrock carb at 5 years, the shaft hole is worn out, no more edelbrock carbs for me. I would try a $99 edelbrock performer intake, though, my weiand does not allow the 255 to fire on two cylinders cold unless the vacuum secondaries open up. (Which proves no electrical problem). That is why my winter milage is only 14 on a lot of short trips. 1980 granada electronic ignition with .060 plug gap did not help the idle miss. I've got a 70's 302 with edelbrock performer intake and cam and carb in a fairlane, it idles a lot better than the 255.