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Discussion Starter #1
Im going to rebuild a 1972 351C. with 2V open chamber heads. How much HP. can I get out of these heads? I was looking to get around 350-375 HP. will these heads do or should I start looking for some 4V heads?
 

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what is the limiting factor at that HP.?

ps. this motor is for street use only
I think he's just saying the heads have the potential to make more than 375 hp. If you put enough cam, carb, compression, and induction you could make more than 375 hp with those heads. It doesn't sound like you want a tempermental high octane motor though.

The open chamber 2 barrel heads would be a good choice for a low mainentance, relatively low rpm, and relatively low compression street motor.

One thing that would help IMO, is to get some port work done on the heads. I think some pocket porting and maybe a little cleanup of the ports themselves would be really helpful. I can't stress this enough. You might pick up 15-20 hp with no downside other than the modest expense of the work.

paulie
 

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As for how much hp you can make, here is a rule of thumb. This is just a rule of thumb, but it gives you an idea. Take the max intake flow of the cylinder, multiply by .25714 and multiply that by 8 (for the number of cylinders).

You can simplify that if you have a V8 by just taking the max intake flow and multiplying it by 2.057.

I googled a couple of flow figures for unmodified 2 bbl heads and found 186 and 192 cfm. Take those figures times 2.057 and you get 383 hp and 395 hp. That is a very general idea of what you could get with unmodified 2 bbl heads in a maxed out combination.

I keep saying "general idea" and "rule of thumb' over and over so I don't get flamed by anal retentive internet keyboard jockeys itching for a victim. Get back you fiends! :) Because figuring horsepower potential is much more complicated than that.

Nonetheless the above formula is useful.

Take home message: 2 barrel heads could be good for a mild 351 in the 350-375 hp range. Some port work would worth the dough!

I think you can find flow figures for ported 2 bbl heads in the 225-230+ cfm range depending on the extent of the work. Maybe some Cleveland guys will chime in with some flow figures for mildly ported and fully ported 2 bbl heads???

225 cfm x 2.057 = 463 potential hp.
230 cfm x 2.057 = 473 potential hp.

That's not necessarily the hp you would get. It's an estimate of the max hp you could get if everything is "maxed out".

Any money you spend on good and appropriate port work is worth it.

JMO,

paulie
 

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About 20 years ago a guy I know bought a boss 351 Mustang. It was a dog at all speeds below 4000 RPm.. I got some 2 V heads, ported them quite a bit, and with a matching Edelbrock 2 V intake, the car PICKUP 7 to 8 tenths of a second , and 4 to 5 MPH in the Quarter mile. I did not rubn the engine on the dyno because he did not want to take the motor out of the car- I figure the the head swap was worth around 60 to 70 HP


JOE SHERMAN RACING ENGINES
 

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That sounds like one very badly cammed Boss to me.....



I keep saying "general idea" and "rule of thumb' over and over so I don't get flamed by anal retentive internet keyboard jockeys itching for a victim. Get back you fiends! :) Because figuring horsepower potential is much more complicated than that.
I love the above quote Paulie.... :D

You are pretty much on the money imo. The 2V's have potential and as stated, with alittle clean-up work, they actually perform quite well and are not as "fussy" cam wise as the big heads for street manners.
 

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I love the above quote Paulie.... :D

You are pretty much on the money imo. The 2V's have potential and as stated, with alittle clean-up work, they actually perform quite well and are not as "fussy" cam wise as the big heads for street manners.
Hey thanks man. I really appreciate it. Feedback is generally 95% negative or combative. Just one response saying "yup" means a whole hell of a lot.

Let's help each other out yo! :)

paulie
 

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Discussion Starter #12 (Edited)
Thanks for all of the info its realy been a big help. I realy dont know to much about the 351C. this is my first one. Ive always heard them refered to as a great tough legendary motor. Ive always had fords and the motors where always in the Windsor family of engines so this is realy realy neat for me and its teaching me alot about the the older fords.


PS. my old man has told me alot of war stories about these old engines(second gen.ford lover) Never had any luck with the rest!
 

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I realy dont know to much about the 351C. this is my first one. Ive always heard them refered to as a great tough legendary motor.
The 2V version was for mild applications, if you're talking about the legendary Cleveland it would have to be the 4V.

I'm not against the 2Vs but with all the aftermarket heads available now it doesn't make sense to spend a lot of time and money on them.
http://www.ausfordparts.com/
 

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Oh, for sure Brian.... the 4V's are what their reputation is built on.... but do you need them (or aftermarket heads) for a 375hp goal ??? Even without porting and good component selection you should achieve close to that with 2V's, but a clean-up makes life easier... the ports and valves are plenty big enough, not like the Windsor factory stuff.
There are afew getting over 500hp with stock ci's, so if you get serious with the grinder (and the $'s) they do work.
The "true" cost of putting a set of aftermarket heads on is way more than the cost of those bare castings....and most need a specific intake as well, the "cheap" regular Cleveland intakes have major port mismatch and in most cases won't work without alot of work....
 

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Discussion Starter #15 (Edited)
I really set my goal on 350- 375 HP. for some different reasons, first is that its in a beautiful 68 fairlane 500 fastback that will only be driven on weekends and to car shows and sometimes to show up the local chevy lovers.Second is that I figure 350-375 HP. should be a semi inexspensive upgrade so if I could keep the original 2V heads and ive already got the edelbrock 4V for 2V heads intake on it it should help the $$$rs a little.Also it has real working ram air with a factory looking air cleaner under the hood so when its done the entire motor will be painted ford blue (no crome) and reinstalled. Third ,this is an old classic car with not the original motor but an old classic motor, even if it is a 2V motor its still a classic. You can find a 351 or 302 W just about anywere and punch it out to 500 HP if you have the money,but not this motor in this car its an "old classic" ... I dont mean to ramble on about this but these cleveland motors are going to get harder to find in the next 10 to 20 years so we should try to preserve them more instead of turning them into a moving chromed out HP circus. Mine has about 240 bulk HP right now and its still pretty fun to drive,but I just want a little more power under the hood when its rebuilt this year or next year.

My next project when this car is done is late 80s notchback mustang with a punched out 351W and 5 speed with probably 390 series gears. that will be "my" moving chromed out HP. circus!

I really dont mean to be negative its just how I feel about some of these older cars with these old engines in them ,and I really appreciate all of the positive feedback and if I can ever help with info on some of the newer models mainly Windsors I will try my best to help.......
 

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I really dont mean to be negative its just how I feel about some of these older cars with these old engines in them ,and I really appreciate all of the positive feedback and if I can ever help with info on some of the newer models mainly Windsors I will try my best to help.......
I don't get the feeling you are being negative at all.... it is YOUR project.
I admire you for choosing to use the "old" Cleveland, the reasons for your choice and am quite sure you will be happy with the outcome.
Good luck...
 

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Discussion Starter #17 (Edited)
I don't get the feeling you are being negative at all.... it is YOUR project.
I admire you for choosing to use the "old" Cleveland, the reasons for your choice and am quite sure you will be happy with the outcome.
Good luck...

Thanks alot I realy appreciate that...

Im a real car nut ,I believe some cars are built to have an abusing kind of fun with ,and some that are original and older in good shape should be taken care of.

Dont get me rong I used to have a saying (drive it like you stole it!) but for me I guess that doesnt aply to everything.

PS. Thanks again for all the positive feedback and info...........
 

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....these cleveland motors are going to get harder to find in the next 10 to 20 years so we should try to preserve them...
I bought a 351C 2v 2 years ago for 150 bucks, haven't gotten to it yet, but if I remember right it has just over 70,000 miles on it. I can turn the crankshaft pulley by hand too! Hopefully soon I will be able to dig into my first cleveland mill.
 

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Do you need an iron 4V or aftermarket head to make 375HP? No, I never implied anything close to that. My advice was about time and money.

Iron 2Vs have a poor intake short turn radius that isn't easy for a first time porter to get right. Porting is very time consuming...not bad for a DIY project if you have the tools and determination but I wouldn't pay a professional to work on that type of head.

The open chambers are a problem for getting decent compression with a flat top piston. Figure about 9.25:1 tops for a zero decked, stock stroke engine.

Now figure out what you have to spend at a machine shop to get the heads reconditioned. Disassembly, cleaning, magnaflux, resurfacing, new guides, hardened seats, valve job, machining for screw in studs, etc?

I'm not saying it will need all these things...it's just good to be aware of expenses that may be needed to make an old head like new before comparing price to an aftermarket bare head.

I don't think I have to go into the obvious advantages of new technology.
Aus Ford Parts - Aussie 351 Cleveland Specialists
 

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Brian, I know where your coming from.... I have sung the same tune in the past... for performance builds - the new generation heads have much more potential. Expect to cough-up $2.5k+ for heads, hardware and intake before you start though.

But, I get the feeling you are not taking in what he is saying here....
 
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