Cleveland 4V Heads

[Mercracer]

Anyone running 351C 4V heads on a 302-331 engine?

[Christoph]

Mercracer,

Ford put 351 Cleveland heads on 302's in '69 and '70 and called them Boss 302s... ;-)

With all of the available aftermarket Windsor heads why would you consider Cleveland heads?

Just curious, however, to answer your question I have never put Cleveland heads on a 302 but have seen several that have. It is really not that difficult. There are probably sources of information on the web for the correct steps. If you go with the 4V heads you will need a Boss 302 intake. If you go with the 2V heads there was a company down in Arkansas that made aluminum intakes for the swap called the "Street Boss". Even though the Clevelands have the massive valves and ports the exhaust ports are still quite restrictive. Not a lot can be done to the exhaust port on the Cleveland, that I am aware of anyway, to improve it a great deal.

Good luck!!

Chris

[Mercracer]

Chris
Thanks for replying, but I am pretty hard core with the late 60's and early 70's Ford/Merc parts and am very familiar with how to put them together. I have a stash of Cleveland 4V parts including heads that are collecting dust. I am picking up a Boss 302 intake for a reasonable price, and may combine the parts on top of my Mexican 302 block for something different in a Fox body car.
My question, being posted on a primarily late model board, was to check for recent success/failure stories. I asked a very vague question to solicit a wide range of information from experiences which may be out there.
As long as True Street, Wild Street, Open Comp. and other open classes exist, I think that these "dinosaur" heads still have a use. It takes a Victor Jr. head to out flow the "restrictive" exhaust ports.
If a person is starting out with E7 heads, then I would never advocate going out and paying the premium price for a set of the 4V heads and going through the troubles to make them work, but I do believe that they still have a place.
If they were inherently terrible heads with no potential, then they would not be prohibited from nearly every NMRA, Fun Ford, and World Ford Challenge heads up class. Not forgetting to mention the Pro Cheap Street class also.

Ed

[Christoph]

Ed,

I am sure those heads would work great on the 302 if you have the internals to get the RPM's up to put them to use.

Regarding my comment on the "restrictive" exhaust ports, I was going by a book I read once regarding a design flaw in the port of the Cleveland head. I don't recall the title of the book as it was a couple of years ago but it was not a Ford specific book. I have never messed around with the Cleveland motors, they just seemed too expensive to build. If you already have the parts, etc..to get them to work I am sure you can build a great running 302.

There is a fella around here running a 408 Cleveland (4V iron heads) with a 351 9.5" deck block. From what I understand the car runs in the high 9's. I don't know the other details of the motor but it obviously runs strong!!

Chris

[BlackBelt]

I messed around with quite a bit of Boss 302 stuff several years ago. The intake ports are too large for good air velocity on that small an engine unless you take it up around 9000 or more and even then your HP curve is very peaky. You can fill the bottom of the port and pick up the velocity with very little loss of airflow. I would consider this manditory if you want good performance.


Several years ago I had a couple of interesting discussions of this engine. The first was with one of the drivers on the Shelby Can-Am team. He told me that they had to go to each race track a week early and spend the week trying different rear end and transmission ratios in order for the cars to run competitive lap times. He said the chevy teams just popped in their best guess and ran just fine. The point of the story is that the Boss 302 engine has a narrow power band and the car must be set up just right to run well.

The other conversation was with Bob Glidden back when he was running the Cleveland in his Pro Stocker. He was experimenting with a 347 using the Boss 302 heads and told me he could not make it perform with the 351 version.

From all I learned from personal experience and the above stories I would recommend staying with 351 or larger displacement with the taller deck blocks. The filled ports will certainly help flatten the power curve but the taller block combinations will make more power.

[Mercracer]

John
That pretty much jives with most of the information out there, but I am looking for more specific information and actual performance numbers with specific intake and cam applications to see what the combination is capable of, not whether it is the one ideal combination in comparison to all other combinations of parts.
I would like to find out more information on your "tall block" theory, as I suspect that it may have been a function of other supporting hardware that influenced the net output of the two engines than just rod ratio.
A 302 cube Trans Am car, and also Bob Glidden's application is quite a bit different than what I am looking at. A general statement that a 347 could not perform with the 351 version does not indicate that it was not performing, just that his 351 had some performance advantage in his application. He was probably turning the engine 2000+ more RPM than I will be, and I will also be using nitrous to supplement the lack of torque.
My converter flashes at 3500+, and I have a 2800 lb. car, so I am not concerned about the torque curve much below that point.

Thanks
Ed

[BlackBelt]

Well Ed you are right, there is a difference between being fast and winning in competition. If you are running brackets where being consistent is more important than being fast, the Boss 302 wasn't a good combination. The narrow power band made it more sensitive to atmospheric changes than other wider power band combinations. If you are just going to drive around with it it will be fast and fun to drive. It's hard to give recommendations when you don't state what your useage is.

I can't tell what nitrous is going to do to the set up because I never used it. My car weighed about 1600 pounds and I don't recall the stall in the converter but it probably was in the high 4000's. I raced the car for one season, the next year I put a 320 inch Chevy into the car and went faster.

[Mercracer]

John,
At this point I am not necessarily looking for advice on specific combinations, although I would like to hear about performance numbers in an engine that runs under 7000RPM.
Back to my original question, what I am doing is asking if anyone is currently running the 4V heads on a combination, and with that I would like to hear past personal experiences.
More specifically I should be asking for any success stories and best performance results people have had with a 302-331 or even 347 cube motor. I know that there are many opinions and stories of how bad they are on low RPM small cube motors, and how x, y, and z heads are a better choice, but I know that there must be or have been people who have run them and I would like to hear from them.

Thanks
Ed

[MitchB]

This is not a precise answer to your question, but I am looking at a Popular Hot Rodding Engine Annual circa 1971. It has a feature comparing a Chevy crate engine to a Boss 302 crate engine. As delivered from Ford, straight out of the box and only run-in on a dyno, the Boss 302 made 327HP @ 6600 RPM and 290 ft-lb of torque @ 5800 RPM. This was with dyno type headers. With an open plenum type 2X4 manifold, Ford's then current Trans-Am camshaft kit and with the heads ported by Valley Head Service, the engine made 440 HP @ 7600 and 312 TQ @ 6200. They eventually made 500 HP @ 8400 RPM using an experimantal Ford cam, light weight valves and a set of Doug Nash injectors. Noteworthy is this was all done on the untouched factory shortblock! The engine was then dropped into a Mustang and run at Bonneville where it set a new class record.

As you probably have heard, these heads performed much better on the Boss 351, so you need displacement under them. The little 302 was a very peaky engine with little torque. If you are going to do anything with these heads, I'd try to get the displacement up. Roush Racing used to sell ceramic wedges that fit into the floors of the intake ports. I do not know if they are still available. They were supposed to make more power at usable RPM ranges.

Mitch

[Chris89lx]

Mine is not based on a 302 or 351W block but I run a 351 Cleveland in my 1989 Mustang. It has the 4V iron heads and is also stroked to 398ci. With 12.5:1 compression, a Torker intake and a solid cam (.648-.641 lift and 270*-276* duration @.050 lift).
A few years ago on the engine dyno it made 530hp and 450lb/ft of torque. The hp did not peak on the dyno and showed no signs of falling off at 7000rpm.
This year I had it on a chassis dyno with a 275hp shot of nitrous. It put down 702hp and 615lb/ft of torque at the wheels.
The best track times to date are 11.50's at 118mph on the motor and 10.30's at 135mph with the nitrous. I'm sure it will go well into the nines with the nitrous on for the entire run. The track times were also done at 5000+feet corrected elevation.
Not sure if I can help with anything you need but I'll try.

Chris.

[FAH-Q Racing]

I have seen them on a 347, they did fairly well, still to much head for that many cubic inches. However, you can masache the exhaust ports a little to gain some horsepower, because they do have a slight problem, but they will still flow well up to a 351 ci engine. But, on the intake ports is where you can work some serious magic, take some Manley 907 epoxy, fill the bottom of the floors up on the intake ports about 1/4 of an inch, but go all the way to the pocket, then massage it into a nice form, do the same to the intake manifold ports. This not only will increase the velocity by making the port smaller, but will increase the flow due to raising the ports. This I have personally performed in the past, and it is also used by many Ford winston cup teams.

[9secondGT]

Why dont you call MPG Head Service at 303 762-8196. Talk to Scott Main and order a set of port plates (the kit comes with int. and exh. plates) I think they sell for about $90. This is the cheapest and easiest way to make these heads work.
I use them on my combination which is a 393 cleveland with the 4v heads and a custom cam from Scott's other company, Cam Research, and the car has run a best of 9.80@140mph on the motor. Thats a stock 2 bolt main cleveland block and unported 4v heads.
Good luck with your combo and have fun.