does anyone know a good combo for a 351 cleveland?

[Guest tom sixbey]

I've got a cleveland in my 71 mach that i want to rebuild.. I'm hoping for a streetable 450 horses that'll run on 93 with a smooth powerband. I realize i'm probably asking too much from 351 cubes, but i've got the 4BBL heads... anyone know a good combo?

 

 

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Tom 6B (73NIC)

 

"the stupider you make people think you are, the more surprised they will be when you kill them"

-anonymous

[Guest Anonymous]

Tom,

 

I can't remember but I think the 71 4V Clevelands had the "open" chamber heads. You may want to check on this...the bad news with those heads is the fact that you can't get any "quench" because the open chamber covers the entire bore. The good news with those heads is that you get the huge ports and valves...more bad news, due to the huge ports and valves you usually end up with a sluggish street motor due to the lack of velocity in the intake ports...more good news, if it is truly a 4V Cleveland you should have four bolt mains. If I remember correctly 71 was the year they started using four bolt mains on all 4V Clevelands...more good news, throw on a dual plane aluminum intake, a solid lifter cam, screw in studs with guide plates and you basically have a Boss 351...those were about the only differences in the standard 4V Clevelands and the Boss 351, although in 71 the Boss may have had the closed chamber heads...it may not have been until 72 that all of them were "open" chamber...you will have to forgive me but it has been many, many years since I have messed around with Clevelands.

 

Now for more good news, Ford of Australia made closed chamber heads with 2V valve and port sizes...much better heads for a street engine and if you can find a set of these heads they should be fairly reasonable. I know Ford Motorsport used to sell them years back. The Cleveland engine is a much overlooked engine, it is sort of a cross between the 385 series big block and the Windsor small block. You should have no problem making 400 hp with a Cleveland, just be very careful not to "overcam" the motor or it will "throw up on itself" on the bottom end.

 

If you are not interested in using Cleveland heads, which is certainly acceptable with todays aftermarket of aluminum heads, it may be a wise choice to use Windsor heads. With a few modifications to the water passages you can use Windsor heads on a Cleveland. The benefits of this combination is the strength of the Cleveland bottom end and the "torquey" Windsor heads. I believe Ford Motorsport still makes an aluminum intake for the Windsor heads on the Cleveland block. You can also use a cam from a Windsor motor but my recollection of the details are even more sketchy than those already given.

 

If you want 450 hp on 93 octane fuel you are going to have to have the closed chamber heads. The open chamber heads had detonation problems even with the ~8.8:1 from the factory. Getting a good quench will allow a higher compression ratio without the risk of detonation. It is really a shame that the aftermarket didn't develop more pieces for the Cleveland, it is possibly the best engine Ford made...

 

Chris

[Guest Anonymous]

Totally agree Chris. My father in law had a 71 torino fastback with a 351c, with stock duals, factory cast iron intake and a basically stock production cam (it may have been on the healthy side of the production cams ) it had some serious legs. From a dead stop it wasn't much to shout about, but stomp it to the floor on the freeway and yeah buddy it would pin your ears back. I honestly don't know what the top end was, but I had it buried at 120 on a number of occasions and it had at least another pony or two left.

The good news in using it in a swap, is we don't need buckets of torque in the Z. Probably have to put it behind a top loader though, or find if the T56 for the Ford will fit any of the cleveland bellhousings. Probably fit better in the Z than in my wifes old 72 cougar. It had a 2v 351c and the middle plugs were all about using swivels to loosen, and then fishing a hose in there pushing it over the isolator with your finger tips and to try and screw the plug out. Not fun at all. (and they put 390's in there as well, worked on a eliminator GT 390 cougar in the 70's, put headers on it of all things.. major bitch..)

 

Lone

 

[This message has been edited by lonehdrider (edited December 25, 2000).]

[blueovalz]

Just my .02 worth. I built a 302 using the 2v Cleveland heads. They were fantastic for this displacement. The port sizes are bigger than the 351W but smaller than the 4v Cleveland heads. The torque will be very good for the street 351ci displacement with moderate to good upper end with the proper components to go along with it. It is a closed chamber head too. Don't discount this head, it is really just shy of optimum in the porting compared to the overly large (IMHO) Cleveland heads (street duty).

 

Terry Oxandale

[Guest Anonymous]

Terry,

 

I looked at your car in the featured car section. Wow. Very, Very trick. Alot of really good ideas, I like the venting of the radiator air out the hood and the body panels look super. And of course the Shelby paint scheme looks superb. Very nice job. Congrats.

 

Regards,

 

Lone

[Guest tom sixbey]

well, it seems that my cleveland is probably of the open chamber variety.. thanks guys for all your info.. I'm trying to think of what i can do for my mustang and zcar situation.. but i've got too many questions to hit right now...

 

I was planning on stroking up the cleveland to about 400 cubes though.. with it drawing more air, i figured it would actually take advantage of those big ports and valves - do you guys think that would make up for it's lack of torque?

[Guest Anonymous]

Terry would probably be more versed to answer this as outside of a little maintanance I'm not super knowledgable on the Cleveland, but I'll give part of it a stab. I think it depends if you don't mind having a lumpy cam and having a soft bottom end. My opinion mind you, but I think you would need a long duration cam that would probably be soft until at least 2500-3000 and then pull like crazy to 7000 rpms? I think that would be required with those big ports to sufficiently fill the cylinders.

 

Heres a link showing the specs of a '70-'73 cleveland:

http://www.thecarsource.com/fords/engines/351engine.html

 

It appears the compression (11:1)is way to high to run 93 octane I would think. Lower compression isn't going to help your goal of 450 hp much, but I dont think its unobtainable. I'm not sure I'd stroke it though, maybe in a heavier car.

 

 

Regards,

 

Lone

[Trevor]

Terry,

Did you use a BOSS 302 intake manifold to put those 351C-2bbl heads on a 302?

 

 

Wow look at all the Virginia folks on this Forum

Bryan

Jamie

.....

[blueovalz]

B&A Ford in Fort Smith AR sells (or sold) the manifold. I think it was called a "Steet Boss" intake. It's ports matched the 2bbl heads. The BOSS manifolds ports were much too big for the 2bbl heads and the missmatch may have been detrimental to optimum performance. It was a great combo if anybody comes across one. In regards to the 351, it has the huge ports, but not well designed on the exhaust side. In fact, the big thing to do on them was to put plates in the exhaust to "straighten" the exhaust flow (they had a BAD hump on the floor of the exhaust port), or mill the exhaust side of the head off (up to about half way up the port), and then bolt on an aluminum block with ports machined in it to straighten out the OEM port. The exhaust plate that straightened out the exhaust worked good, but effectively cut the port volume down by about 35%.

 

Terry

[Guest RON JONES]

A very good friend of mine runs a NHRA Super Stock Mustang with a cleveland in it.He is limited to,I'm guessing here,but I think its 9 to 1 compresion.I know for a fact thats its low compresion.He uses the 4v heads and a monster roller cam.He spins this thing to 8000rpm.The intake ports are(as mentioned above)huge,even for his aplacation.He use's a good two part apoxie to fill and make the intake runners smaller.He adds to the floor of the runner,and this also creates a raised intake runner and is proven on a flow bench to flow a lot better than the big stock runner.I have seen Him do a set of heads and it really isn't all that hard to do.I don,t think stroking the motor is the cure for the stock intake runner.By all means go for the stroker motor,but the intake runners are still going to be to big.Don't get me wrong I'm sure it would run good,but it would run a lot better with reworked cleveland heads,or some of the options mentioned above.If you choose to go with the apoxie trick,I can find out in detail what you have to do.You would have to do the intake as well.

[zgeezer]

Rather than stroke a 351C, consider a 400M truck engine. It is a cleveland with a higher deck height and 400 ci. The 351C 4barrel carb heads will bolt right up, a four barrel 351C intake manifold will also bold up if you use the spacers that Wieand sells (sold). There're easy to fabricate as the cleveland intake is "dry". 351C ran well and the 400 can make better use of the intake ports and valves of this engine. Having said all this, the practical engine might be a stroked 351W (426cu from Coast Mustang) and aftermarket windsor aluminum heads. Light, current, and some real torque.

zgeezer

[Brad-ManQ45]

I used to have a '72 "Q" code 351 CJ Mustang

- a 71 engine. As the car was built in 1971 they could use the '71 engine. Cars built in '72 had to use the "R" code engines.

 

The CJ was the first 351C to combine open chamber heads and 4V Ports. If you have a regular 351C (w/11:1 C/R), then I believe someone makes a plate that will bolt into the intake to reduce the size of the ports for street use.

 

I wouldn't stroke it, and I wouldn't use the 400 block - too heavy. I had a 3.25 rear gear, Torker Intake and a 780 Holley w/headers on mine and it did not lack for low end torque and would scream up top. Most would say to use a 3.91 aor 4.11 rear gear w/ the torker but honestly, I had more than enough down low on a 3400 lb car.

 

If you are going to use a double pumper, don't go any bigger than a 700 any more and you will lose area under the power curve. The CJ used the same profile cam that the 428CJ used - and to good effect - the duration let it live well on pump gas.

 

If going to strok use the 351W block, 400 crank, custom pistons and LONG RODS. This will reduce tendancy to detonate w/higher compression.

 

Remember that if you use aluminum heads (from FM), you can get another .5 point in compression w/o detonation.

[Guest Anonymous]

I know that nobody has posted on this for a while. but i was bowsing through and thought I would comment on those 4v heads. If they have such large ports wouldn't they work primo with a nice turbo or super charger? if you could get the spoolup on the turbo to be real low that should help out with speeding up the sluggish air flow off the line right?(obviously the supercharger won't have this problem) maybe even improve throtle response?

 

I'm not really one much to talk since i've never tooled around with a either but i thought i would post my opinion. 351c running 15-20# of boost aught to be real fun to play with.

 

[ May 22, 2001: Message edited by: v-8 Zfreak ]