I have a 1971 XY Falcon with a 351C with 2V heads. I recently had the engine reco'd with new pistons, valves, bored etc. and have fitted headers and dual exhaust, a factory 2V intake to suit a 4 barrel carby (Holley 750 vac sec.) and a mildly lumpy cam (power band approx 2000-4500rpm - sorry i don't have the specs), an electronic distributor and ignition coil and use a C4 with 2500rpm stall. I am looking for (reasonably easy ways) of getting more power. My heads are still stock (ie no porting/polishing) and I have considered getting this done along with a new intake manifold (like an edelbrock torker maybe?) Does anyone here have any ideas of getting more hp? (I have considered changing to a 4V head setup but this would require new headers etc so probably too expensive). Also, does anyone know what a safe hp/rev limit would be considering i am still using cast pistons etc? Any help would be appreciated, as would any web sites which deal with improving Cleveland power

 

[font size="1" color="#FF0000"]LAST EDITED ON 16-Sep-01 AT 08:06 AM (EST)[/font][p]Wow - that's a lot of questions! All experienced Cleveland builders advise not to port or polish the Cleveland heads - just be sure it has a decent valve job and all hardware is up to the task. As far as moving to a 4V head - these ports are huge and are hard to fill on a naturally aspirated street engine. If you do go to the 4V heads, figure on a different intake, carb, and headers/exhaust to get the air in and out faster. A different cam profile may help also. Your performance band will move up in RPM's so it would be harder to take advantage of the 4V heads on the street. The problem is port velocity - to keep it high on the 4V heads you need either RPM's or a blower/turbo. I am having to live with them as a vehicle I recently bought has a 351CJ with the 4V heads. I suppose 5500-6000 is realistic for short blips as long as you pay attention to the head hardware.

The 2V heads already breath pretty good so a compromise may be to have your 2V heads modified to take slightly larger valves. As far as other methods - you did not say what compression ratio you used. You should be able to get close to 10:1 on street gas. If you have not already done so, go to an open air cleaner with a K&N filter, and put a 'straight up' timing gear/chain set on. Note that if you go with a single-plane intake such as a Torker, you may not have enough vacuum for the C4, so you would need a vacuum resevoir.

I am intrigued by the idea of mating the 4V heads to a 400 block as the 400 would move more air at lower RPM's than the 351. One fellow on this board has done this and being a 400 fan, I look forward to trying this sometime...

Tom

 

"All experienced Cleveland builders" eh? The guy I bought my block & heads from has been building racing engines for years and he ports & polishes every Cleveland head he uses. You might also want to check out the Hot Rod article on the 400 build up which uses the "recipe" from a Ford racer. The porting is not over done, basically gasket matching, but the pocket porting & polishing is quite extensive. Why on earth would anyone not want to make the head breathe better? Heads are where virtually all the horsepower in an engine is made.

 

The Cleveland is quite a powerful engine and tough too. DO NOT TURBO OR SUPERCHARGE IT. I know some people do but it is 'supid' it vastly reduces engine life. The XY with a good 351 should do 0-60mph in 6.2 sec and get to 140-145 mph, no worries. I wouldn't rev past 6500, the factory said 6150 but they could go higher. 11:1 compression helps. Make sure you have a 3 or 4 core radiator and I would advise on at least 1 extra electric fan, because clevos can get hot. A 750 or 780 cfm dp holley is sufficent, anything bigger is overkill. Putting 4V valves into 2V closed chamber heads is WICKED!! and doesn't reduce engine life like a supercharger. The XY can easilly be fitted with a cold air intake (shaker) which helps too. While your at it install a high volume oil pump, baffeld sump and maybe an oil restirctor kit. The toploader 4 speed is my preference in gearboxes but the C4 is pretty good too. Diffs are the 9" type, in 3.25:1 and 4.11:1. I'd go for the 3.25 or even the 3.00. Good on you with the electrics you have done the righ thing, but remeber Clevos like advance, and use the COLDEST spark plug you can get. 2 1/2" dual exauste is good. Phase IV extractors are the best but I think they need 4V heads.
You're onto a winner here mate, the 351C goes like a cut cat.
335C

 

Yeah - never say never or all. I should have said many - and qualified it. While the Cleveland heads can benefit from porting and polishing, they breathe much better than other stock heads. If you are building a street engine on a budget, as many folks are, this is one corner you can cut. If you are racing and/or have the money or personal experience to port/polish, go for it.

Tom

 

I have a set of 2V heads on my 400 and I spent quite a bit of time taking out the exhaust bumps, smoothing the chambers, unshrouding the valves, cleaning up the pockets and smoothing out the port walls. I didn't overdo it and I didn't spend the time to gasket match but I think they should flow a little more efficiently anyway. I did it mostly for the experience and so I could buy more tools! The guy at the machine shop was pretty impressed with the work (of course he could have just been stroking my ego so I'd keep spending $$$ with him)

 

The Cleveland is quite a powerful engine and tough too. DO NOT TURBO OR SUPERCHARGE IT. I know some people do but it is 'supid' it vastly reduces engine life.
<snip>

I was thinking of a blow-through centrifugal blower in the future, just running low (say, 5-6psi) boost. Hmmm. might do some more research.

<snip>
The XY with a good 351 should do 0-60mph in 6.2 sec and get to 140-145 mph, no worries. I wouldn't rev past 6500, the factory said 6150 but they could go higher. 11:1 compression helps. Make sure you have a 3 or 4 core radiator and I would advise on at least 1 extra electric fan, because clevos can get hot.
<snip>

I have open chamber 2V's, ie only like, 9:1 compression. mind you, I could alwars het high comp. pistons. I use a 3Core radiator + shroud from an XE v8, but it still gets a bit hot sometimes. the electric fan is on the list for sure.

<snip>
A 750 or 780 cfm dp holley is sufficent, anything bigger is overkill. Putting 4V valves into 2V closed chamber heads is WICKED!! and doesn't reduce engine life like a supercharger. The XY can easilly be fitted with a cold air intake (shaker) which helps too.
<snip>

I have a new 750 vac. sec. squarebore holley with a 1" spacer. Maybe I'll go 4V valves when I get the heads ported (unless it already has them; think I need to ask the guy who built my engine). I have a shaker and the bonnet supports but haven't got the hole cut yet. It's being done in a few weeks. Should give it a few more ponies up high and when sitting in traffic.

<snip>
While your at it install a high volume oil pump, baffeld sump and maybe an oil restirctor kit.
<snip>

I haven't got any of these things. Is oiling really a problem with the Cleveland or only if you try and sit it at 6000rpm all day?

<snip>
The toploader 4 speed is my preference in gearboxes but the C4 is pretty good too. Diffs are the 9" type, in 3.25:1 and 4.11:1. I'd go for the 3.25 or even the 3.00.
<snip>

I wanted a manual originally, but this car came along with everything else exactly as I wanted it. I have the C4 with a 2500rpm converter, still running through the stock 6cl borg warner slippery diff (my car originally had a 200ci 6cl). It has 3.25:1 gears though, so I'll wait till it breaks before I replace it (it's lasted almost a year already!)

<snip>
Good on you with the electrics you have done the righ thing, but remeber Clevos like advance, and use the COLDEST spark plug you can get. 2 1/2" dual exauste is good. Phase IV extractors are the best but I think they need 4V heads.
You're onto a winner here mate, the 351C goes like a cut cat.

>>>>I have the 2.5"dual exhaust. I am using Hurricane headers (which came with a whole pile of bits when I bought the car) and it sounds wicked, especially with the Heatseeker cam.

 

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
I was thinking of a blow-through centrifugal blower in the future, just running low (say, 5-6psi) boost. Hmmm. might do some more research.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
I'm not too sure - It's your motor you can if you won't but if it were mine I would not force feed it. Although only a little boost might not hurt.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
I have open chamber 2V's, ie only like, 9:1 compression. mind you, I could alwars het high comp. pistons. I use a 3Core radiator + shroud from an XE v8, but it still gets a bit hot sometimes. the electric fan is on the list for sure.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
Yeah the electric fan is a good idea
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>

I have a new 750 vac. sec. squarebore holley with a 1" spacer. Maybe I'll go 4V valves when I get the heads ported (unless it already has them; think I need to ask the guy who built my engine). I have a shaker and the bonnet supports but haven't got the hole cut yet. It's being done in a few weeks. Should give it a few more ponies up high and when sitting in traffic.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
Good idea. The 750 Holley is an excelent carby for the XY V8.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
<snip>
While your at it install a high volume oil pump, baffeld sump and maybe an oil restirctor kit.
<snip>

I haven't got any of these things. Is oiling really a problem with the Cleveland or only if you try and sit it at 6000rpm all day?
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
Yeah your're right oiling problems with the 351 mostly always happen at high rpm. But since you said you were looking for power I naturally assumed you were going to rev it a bit. No not really I'm sure your a good little boy who sticks to the 100km/h speed limit like me hey???? (jokes)
<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>
I wanted a manual originally, but this car came along with everything else exactly as I wanted it. I have the C4 with a 2500rpm converter, still running through the stock 6cl borg warner slippery diff (my car originally had a 200ci 6cl). It has 3.25:1 gears though, so I'll wait till it breaks before I replace it (it's lasted almost a year already!)
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
Yeah the C4 is ok. The borg warner shouldn't blow up unless it is really strained, but if it was meant for a six it might.

One question, did you notice a slight increase in power when you went form the 200 six to the 351 V8 at all?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
I have the 2.5"dual exhaust. I am using Hurricane headers (which came with a whole pile of bits when I bought the car) and it sounds wicked, especially with the Heatseeker cam.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>
That souand like it's ok to me.
335C

 

OK!!! I just put a new manifold onto my 351C. I have one of those 'torker' style ones (by Redline, an Australian company). I had to set the idle quite high to stop it stalling in drive, but it breaths sooo much better at high rpm's than the stock intake! Better than what i expected, and that wlways makes me happy)

 

i think the 5-6psi will be good fir the 4v heads. one note here on the oiling issue. the only time i ran afaoul of it was when i was cruising (135mph+) home from york pa to berwick pa. this was on a fall night using I81 over the mountians, after a good hour and a half the connecting rod bolts broke. it kept running, with a lot of oil and prayers. then i needed a new motor, never really beleived all that oiling stuff, i had used that motor for a lot of road racing as well. I believe the 351c is a very stout motor and one can rev it to 9k and up for revs, just dont keep it there.

 

 

May I ask what you did to get electronic ignition in your cleveland?I am presently trying to get my rebuilt cleveland going,but havn't fiqured out yet how to hook up the electronic ignition because I don't know what distributor to use.The motor is presently in a 78 f1504x4.duraspark 2 I beleive.(jason.pranschke@city.ottawa.on.ca) I would appreciate any assistance.

 

It's me, Christian; I changed user names a while back.

The distributor I am using is a Ford Australia factory electronic ignition type as fitted stock to all cleveland motors made here from '79-'82. Apparently these are a bit bigger (or is it smaller? I can never rememeber) than the previous points-type distributors (the hole in the block is bigger as well duh). In any case, although there are many around here, they won't just bolt into your US 351C. You could install an aftermarket electronic ignition module but I don't know if it would really be worth the effort/cost.

 

Well tanks for the info