1st step to increase HP?
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1st step to increase HP?
Hello,
I have a 239 original flathead (F-5). Can you advise me on the 1st thing to do, to increase the power. I don't have $2 grand to sink into it. I'm looking for the most increase with the least money. One friend said a general overhaul. Another said change the heads. Do headers make much of a difference?
Thanks for your expertise.
Brad
Kentucky
I also posted this on FTE "Performance engines"
I have a 239 original flathead (F-5). Can you advise me on the 1st thing to do, to increase the power. I don't have $2 grand to sink into it. I'm looking for the most increase with the least money. One friend said a general overhaul. Another said change the heads. Do headers make much of a difference?
Thanks for your expertise.
Brad
Kentucky
I also posted this on FTE "Performance engines"
Lead Driver
Joined: Apr 2002
Posts: 8,813
Likes: 13
From: Littleton, New Hampshire
Brad,
I'd go to the darkside and replace it with a 351. It takes money to get a lot of HP out of a flathead....money better spent on a more modern engine in my opinion. Asking a 239 flattie to haul around an F-5 is a tall order...
Vern
I'd go to the darkside and replace it with a 351. It takes money to get a lot of HP out of a flathead....money better spent on a more modern engine in my opinion. Asking a 239 flattie to haul around an F-5 is a tall order...
Vern
Postmaster
Joined: Apr 2000
Posts: 3,890
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From: La Verne, California
Brad
If you follow that suggestion, you'll be doing just what you do not wish to do, spend lots of Rhino as you'll have to change the location of & make/purchase new engine & trans mounts, purchase new engine, trans & propeller shaft, adapt the cooling & electrical systems & maybe even beef-up the front-ends suspension.
Well how tired is the engine?
Does it need a to be rebuilt? (b&b & p&p if needed)
Maybe it just needs a Ring & a Valve job?!. (bearings as well?)
Making it breathe better (intake & headers), a larger out-put CFM carb., changing to better heads, maybe a different cam.
If the 239 couldn't handle the work the F-5 had to do, it wouldn't have been installed in the first place & Modders will Always suggest that you do an Engine/Trans swap as it's just their nature.
If you follow that suggestion, you'll be doing just what you do not wish to do, spend lots of Rhino as you'll have to change the location of & make/purchase new engine & trans mounts, purchase new engine, trans & propeller shaft, adapt the cooling & electrical systems & maybe even beef-up the front-ends suspension.
Well how tired is the engine?
Does it need a to be rebuilt? (b&b & p&p if needed)
Maybe it just needs a Ring & a Valve job?!. (bearings as well?)
Making it breathe better (intake & headers), a larger out-put CFM carb., changing to better heads, maybe a different cam.
If the 239 couldn't handle the work the F-5 had to do, it wouldn't have been installed in the first place & Modders will Always suggest that you do an Engine/Trans swap as it's just their nature.
Posting Guru
Joined: Jan 2002
Posts: 1,002
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From: Midland, Texas
Rebuilding or overhauling will not increase your stock horsepower, just get you to what it is supposed to be. The first thing to is to see what better heads, intake, cam, headers,or whatever, cost for your flathead. Before you start adding these parts you probably need a rebuild so that what you have will stand up to increased loads. I suspect that 2k would not get you very far.
Ring sets $60, stock heads, $70, pistons $195, rod bearings $256, cam bearings $23, Valves $52 or $128, valve seats $28, valve guides/keepers/tool $65, valve springs $32 or $48, lifters $192. These are parts for the rebuild, no gaskets or water pumps, fuel pumps, carb rebuild and on and on. This is around a grand in parts, more or less. For all of this you get your stock flathead V8 and less than 200 hp.
Vern's answer will probably involve alot of your time... but less of your cash for increased horsepower and that's where you said you wanted to go.
love them hotrods, himmelberg
Ring sets $60, stock heads, $70, pistons $195, rod bearings $256, cam bearings $23, Valves $52 or $128, valve seats $28, valve guides/keepers/tool $65, valve springs $32 or $48, lifters $192. These are parts for the rebuild, no gaskets or water pumps, fuel pumps, carb rebuild and on and on. This is around a grand in parts, more or less. For all of this you get your stock flathead V8 and less than 200 hp.
Vern's answer will probably involve alot of your time... but less of your cash for increased horsepower and that's where you said you wanted to go.
love them hotrods, himmelberg
Fleet Mechanic
Joined: Jun 2004
Posts: 1,791
Likes: 47
From: Minnesota
If the motor is not tired I would look at shaving the head to increase compression. The factory setup is about 6.8 to 1. Now you can run 8.5:1 easily on pump gas. I am not sure how much you can shave from factory head. That should be fairly cheap to do.
Logistics Pro
Joined: Jan 2001
Posts: 3,789
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From: Connecticut
The 239 Flattie Was in F-6's too.
Hauling around Fire truck tankers. It can do the job.
My F-5 has a freshly transplanted F-6 Firetruck 239 with under 6000 miles on it. Aint goin super highway speeds, but will pull six F-1's behind it.
It's amazing how today everyone pushes Horsepower, "300 - 400 hp" in a little truck, but can't pull a large trailer or boat.
The 18000 lbs (GVW) F-6 strolling down the road with 90-100 hp power plant does just fine.
HP is over rated.
Torque, baby!
Hauling around Fire truck tankers. It can do the job.
My F-5 has a freshly transplanted F-6 Firetruck 239 with under 6000 miles on it. Aint goin super highway speeds, but will pull six F-1's behind it.
It's amazing how today everyone pushes Horsepower, "300 - 400 hp" in a little truck, but can't pull a large trailer or boat.
The 18000 lbs (GVW) F-6 strolling down the road with 90-100 hp power plant does just fine.
HP is over rated.
Torque, baby!
Fleet Mechanic
Joined: Dec 2005
Posts: 1,603
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I agree, my 50 F6 for example, 9ft utility , 200 gal diesel fuel tank, Miller arc welder
cabinets loaded with big tools, hydraulics oils etc, air compressor, and it has a
pintle hook for a 10 ton trailer, all with a flathead in which I refuse to change. We
bought the truck new had one genuine rebuilt in the 50's. Ford had an exchange
engine program those days. The only thing ever done was, years ago we put
a warner from a 51 and got rid of the crunch box. Eaton 2speed of course.!!!!!
Sam
cabinets loaded with big tools, hydraulics oils etc, air compressor, and it has a
pintle hook for a 10 ton trailer, all with a flathead in which I refuse to change. We
bought the truck new had one genuine rebuilt in the 50's. Ford had an exchange
engine program those days. The only thing ever done was, years ago we put
a warner from a 51 and got rid of the crunch box. Eaton 2speed of course.!!!!!
Sam
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Logistics Pro
Joined: Jan 2001
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From: Connecticut
I put in the eaton 2-sp also! had the banjo 6:66 gears before.
and t-98 "syncored silent" no more crashbox!
and t-98 "syncored silent" no more crashbox!
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Lead Driver
Joined: Oct 1999
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From: Kalispell, MT
Dual exhaust will help. Improved carburation will help, but due to the quirks of the loadamatic distributor on your flathead, you'll have to change the dist also.
High comp heads will help - easiest way is to get a set of 52-53 EAB heads and put them one as-is. Cam will help but if you get a re-ground cam you'll need adjustable lifters also.
Reamer and big job are right - you've got enough power if you just use gearing to accomplish what you need. BUT, it's hard to have a flathead V8 and not want to hop it up!
From this link scroll down to horsepower curve to see the advantages of some upgrades.
http://www.241computers.com/ford/Con...s20-32-40.html
High comp heads will help - easiest way is to get a set of 52-53 EAB heads and put them one as-is. Cam will help but if you get a re-ground cam you'll need adjustable lifters also.
Reamer and big job are right - you've got enough power if you just use gearing to accomplish what you need. BUT, it's hard to have a flathead V8 and not want to hop it up!
From this link scroll down to horsepower curve to see the advantages of some upgrades.
http://www.241computers.com/ford/Con...s20-32-40.html
Last edited by mtflat; Mar 21, 2006 at 10:16 AM.
Elder User
Joined: Sep 2003
Posts: 587
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From: Augusta, ME
Easiest couple things you could do to improve performance would first be a set of headers, you can get an econo set for around $120, plus whatever exhaust would cost you to complete a dual exhaust system. You can grind the outer exhaust ports on the block into a "D" shape that will improve exhaust flow too. Second, I'd say a new distributor either dual point or electronic with the coil it needs, probably run you around $350-$400 new, and then a 390 CFM Holley carb with the required intake manifold, run around $500 total if you are buying new. These upgrades would fall well under your $2000 limit, assuming no internal work needs done it is all bolt on. You should replace your spark plug wires and may consider an electric fuel pump too. Pretty much any other "performance enhancing" mods will require more of a tear down of the motor. Just to remove the heads to upgrade or shave them is 48 bolts of P.I.T.A. to me.
Scott
Scott
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You guys are awesome. Thanks so much for the advise. The reason I need the power is that I changed the 6.66 rear end to a 4.10 posi. The truck would only go about 35mph. (there might have been a smarter way to get to 55-60mph, but it's done now). Now, I can go highway speeds, as long as it's down hill! It just lost it's power. Still have original 4-speed trans.
Thanks so much. Any other suggestions are welcome.
Mtflat: where can you find EAB heads? are they cheaper/better than aftermarket heads?
Scott: You ideas sound like things "I" could do. (I'm not a pro mechanic) Thanks.
Reamer: I wish I'd known about the Eaton 2-sp !! (I guess that's a rear end)
Thanks so much. Any other suggestions are welcome.
Mtflat: where can you find EAB heads? are they cheaper/better than aftermarket heads?
Scott: You ideas sound like things "I" could do. (I'm not a pro mechanic) Thanks.
Reamer: I wish I'd known about the Eaton 2-sp !! (I guess that's a rear end)
Logistics Pro
Joined: Jan 2001
Posts: 3,789
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From: Connecticut
Yep the Eaton 2-sp is the rear end. Turns the 4 -sp tranny into 8 gears froward, 2 gears reverse.
You can find them under F-5's and up, turns 4th gear (tranny) and rear high is 5:83.
What size is your truck? with 6:66 it was an F-5?
Thats what was under mine too.
Got rid of that and the "crashbox" 4-sp.
Chuck at chucks Trucks got me a T-98 tranny, same ratios but synronized (like a tranny toady)
You can find them under F-5's and up, turns 4th gear (tranny) and rear high is 5:83.
What size is your truck? with 6:66 it was an F-5?
Thats what was under mine too.
Got rid of that and the "crashbox" 4-sp.
Chuck at chucks Trucks got me a T-98 tranny, same ratios but synronized (like a tranny toady)
Elder User
Joined: Sep 2003
Posts: 587
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From: Augusta, ME
Almost forgot, to answer part of your question... yes, headers do make a difference. Upgrading the headers and putting on a dual exhaust help a lot if you still have the single exhaust with crossover pipe. You'll find all kinds of opinions on what pipe diameter is best, glass packs or mufflers, etc. On mine I used econo headers and extension pipes (pre bent for running from headers to mufflers) from Red's Headers, Smithy's glass packs, and 2 inch pipe from the muffler exiting out the side right in front of the rear tire. Sounds Beeyooteeful just idling or winding up through the gears.
Scott
Scott
Lead Driver
Joined: Oct 1999
Posts: 6,783
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From: Kalispell, MT
EAB heads are relatively cheap - compared to aluminum aftermarket heads. As indicated, they came stock on 52-53 Ford cars.
To find them, hang out with flatheaders and get to be friends with someone who put aftermarket heads on his flatty and has the EAB heads taking up space. Or, follow ebay auctions. Or, hit the swap meets. Or, check the various classified ads onlineat such places as FTE, msn flathead groups, fordbarn, bonusbuilt, etc.
Be careful, you do not want 8RT, 8BA, 8CM, EAC or any other variant. Also, this is a mild upgrade - boosting your cr by 1/2 to 1 point depending on your bore/stroke and may not be worth the effort for you.
To find them, hang out with flatheaders and get to be friends with someone who put aftermarket heads on his flatty and has the EAB heads taking up space. Or, follow ebay auctions. Or, hit the swap meets. Or, check the various classified ads onlineat such places as FTE, msn flathead groups, fordbarn, bonusbuilt, etc.
Be careful, you do not want 8RT, 8BA, 8CM, EAC or any other variant. Also, this is a mild upgrade - boosting your cr by 1/2 to 1 point depending on your bore/stroke and may not be worth the effort for you.
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