Building a 351W

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Feb 2, 2004 | 09:03 PM

red75bronco

Thread Starter

Cross-Country

Joined: Feb 2003

Posts: 87

Likes: 18

From: Colorado

Building a 351W

I found a 87 351W HO engine that I want to rebuild and put in my 75 bronco. I am looking for low end torque and horsepower used for cruising around town and going rock climbing/trail riding.
I want something that will get decent fuel economy and reliable and able to lug at low rpms, 500 rpm.

Here's what I need suggestions on:

Should I buy new gt-40 p heads, $242 each, or get my stock ones rebuilt? How much would redoing heads be, and how much better flowing are the gt-40 p heads.

What kind of cam should I be looking for? I have heard short duration and higher lift for low end torque. i also don't want to get to wild.

What kind of rebuild kits should I be looking at. I've seen some in summit racing for $400 for forged pistons? Or should i look at getting the parts through the machine shop?

What do I need to look for in a good machine shop?

Is it worth balancing an engine? how much?

I am sure I will have more questions and appreciate all your inputs. This is the first engine that I have rebuilt to something other than stock.

Thanks

Feb 3, 2004 | 06:08 AM

victorcharlie

Tuned

Joined: Oct 2003

Posts: 341

Likes: 4

Red: Your doing the same thing I'm considering this spring. I too, don't want anything to radical, and you asked most of the questions I have. From what I've read here in the forums, a new stroked crankshaft might be the best way to increase low end torque and horsepower without the radical idle and rumble the kids want......I would think it would be fairly easy to get 300 to 325 hp from a 351w while maintaining a smooth idle and quiet exhaust.

Maybe someone who has done this will clue us in. I'd be interested to know what you come up with.....

Feb 3, 2004 | 11:05 AM

jwtaylor

Postmaster

Joined: Jun 2001

Posts: 4,496

Likes: 0

Re: Building a 351W

Quote:

Originally posted by red75bronco
I found a 87 351W HO engine that I want to rebuild and put in my 75 bronco. I am looking for low end torque and horsepower used for cruising around town and going rock climbing/trail riding.
I want something that will get decent fuel economy and reliable and able to lug at low rpms, 500 rpm.

Here's what I need suggestions on:

Should I buy new gt-40 p heads, $242 each, or get my stock ones rebuilt? How much would redoing heads be, and how much better flowing are the gt-40 p heads.

The gt-40p flow 196/159 cfm and your E5/E7 flow something like 155/ 122 cfm. Your $242 price if complete assembled new, is a good one. Does require special headers central coast mustang 86-96 truck 661-823-2400, however they may or may not fit your '75 bronco. To have your heads ported to flow like the gt-40p can run $500-700 depending on where you go, but then you don't need to spend an additional $219 on headers, if you need headers then this is no big deal. A few options on people who port stock heads like yours (e5/e7) to flow like the gt-40p:

http://www.hunterstyle.com/thumper/combos.php

www.xsrcylinderheads.com

http://www.jlmcylinderheads.com/

www.powerheads.com

The first three are hand ported the last cnc machined. All provide flow data. This price range could get you a set of aftermarket used ready to bolt down or close to new world heads, either way its your call.

Should you wanna try and port the heads yourself, here are three good websites.

http://www.sa-motorsports.com/diyport.htm

http://www.cmc.net/~xero/Mousesporting.html

http://www.mustangcentral.net/tech/e7.html

You probably have the e5 heads which have a larger thermactor bump than the e7s and a larger combustion chamber, otherwise you could have the e7s, either or it doesn't matter, they are basically the same and everything mentioned applies.

What kind of cam should I be looking for? I have heard short duration and higher lift for low end torque. i also don't want to get to wild.

I have compared different cams in search of the right one with a similar combo as you are after, and the comp cam XE line has been the best when simulated. It offers the most torque and manifold vacuum which is what I think your after. comp cam 1-800-999-0853, they can give you what you want, give them a call and discuss your drivetrain and intended use.

What kind of rebuild kits should I be looking at. I've seen some in summit racing for $400 for forged pistons? Or should i look at getting the parts through the machine shop?

I have heard a lot about summits kits and a lot of people have been satisfied, find out what your machinist uses brand/price wise and compare. You might try PAW performance, they have many options and decent prices in most cases, for $8 you get a 3" thick book that pretty much shows you all your options, no website with products, 818-678-3000.

What do I need to look for in a good machine shop?

Look for a clean shop, if the shop is clean and they are busy, then they are paying attention to detail and aren't getting sloppy, theoretically that is. Another thing get references or positive feedback on a certain shop, if you are unsure/bad feeling/no feedback keep going, trust me on that one.

Is it worth balancing an engine? how much?

Yes, if you wanna pay for it. If you stroke the motor which is another torque building option, it will have to be done regardless. Scat offers a crank, you can use your stock rods, stock type 302 pistons (which are fairly cheap) and you can have yourself a 393. Good luck, let us know what you do, later

Last edited by jwtaylor; Feb 3, 2004 at 11:09 AM.

Feb 3, 2004 | 09:30 PM