I raced the Ford 351C on the dirt tracks of Northern California for 11 years - 1984 thru 1994 - Over the years I used every stock cast iron Cleveland Cyl head made by Ford, 4V closed, 4V open, 2V open and the Aussie 2V closed chamber heads. The Aussie heads were the best by a mile, more torque and more H/P. We competed in the Hobby/Street stock class. (We had 25 feature wins and one championship) Had to run a 2V carb limited to 500cfm (Holley 4412). The cam had a .625 lift - 108* LSA (flat tappet) can't remember duration. Ran the cam advanced 2 or 4 degrees. AUSSIE 2V HEADS WERE THE BEST! - Engine redline was 8500 rpm. I still have a virgin pair of Aussie 2V heads in my collection. In 1992 we won 7 out of 20 feature points races at our local track, We were the only Ford competing at our track. The main events started with 20 cars - 19 Chevys and 1 Ford (mine). After that season there was talk of outlawing the 351 Cleveland engine from competing in the Hobby/Street Stock class. Go Figure. I retired from racing after the 1994 season, after 25 years in the business, (the best of times - the worst of times) The tech official used to call me "Mr. Cleveland" to try and get under my skin, it didn't. Proud to race a FORD. If your into the 351Cleveland engine, check out DragBossGarage on RUclips, a lot of great info there.
@@richardholdener1727 It wasn't a "might work well" situation back then, it did work well. On the dyno and on the race track the 2V Aussie heads proved to be the best for the 351C on the dirt track. With a 12:1 comp ratio and 115 octane race gas it made 447 H/P using a custom Holley 6425 -2V race carb rated @ 625 cfm. We did not dyno it with the 4412 500 cfm unit (forgot to bring it, opps) Today there are many more heads for racers to choose from for a Cleveland or a Clevor build. Thank you for all your hard work and dedication to High Performance Engines, sharing with the world what works and what doesn't. Keep up the great work!
@@abcullens2328 did you notice a huge difference between the open and closed chamber heads is it as great a difference as I've been hearing what kind of power were you making?
@@rossgirdeen3247 both worked well, the 4V closed chamber heads had good top end H/P but lacked bottom end torque and the 4V open chamber heads we're the worst, (lowest torque & H/P). The 2V open chamber heads had good bottom end torque but lacked top end horsepower. The Aussie 2V closed chamber heads gave the best bottom end torque and top end horsepower. My blocks were decked to zero. TRW flat top Pistons. On the dyno engine made 447 HP @ 7000 rpm using a Holley List 6425 - 625 CFM 2V race carburetor, stock cast iron 2V intake manifold with long tube headers on 110 octane race gas. Torque was over 500. Yes the closed chamber heads made a big difference for me. I hope that helps.
Yes I've been reading all the books and articles I can find on the 351c wanting to build a 4v Cleveland the Aussie heads seem to be the ticket though like you said. I wanna run factory iron heads. I know it would be better to just use aftermarket heads.
I continue to love watching your dyno tests and lives, the information you give is a credit to your professional approach. Went over your 400 M vs 302 Test again, 4 years ago. Stock, the 400 M had a tiny carb, with about 9" of Hg Vaccum at WOT with a 368 CFM Motorcraft or 424 CFM 2bbl Autolite. It never got a 500 CFM 4412 Holley that you tested it with. Ford rated the first year 400 M as 265 HP gross stock, but you got 267 HP gross. The FE was rated at around 270 HP gross, so Ford had to make the 1971 debut 400 engine stronger than the 12 year old thoroughbred. Our Australian 351 C gave 171 hp net stock with a stock 2bbl (rated 250 hp gross) and 216 hp net stock (Rated 290 HP gross) with a ThermoQuad. Just a 1978 pre production spec 4bbl iron intake with a Carter ThermoQuad adds 63 hp net on a stock 400 M, making 232 hp net, and drops the WOT vacuum to under 1.5" Hg. The stock 2bbl carbs restrict the 400 M to such a huge degree , it's like the world's most Factory Restrictor plate you can imagine. Exactly like a 250 in line six with a Single Carter YFA carb, 175 cubic inches per 1 sq inch of carb Venturi on each engine. Adding a carb with only 85 cubic inches of engine per 1 sq in of carb Venturi adds exactly 63 HP on a 102 hp net engine. Try it yourself next time you test. You never saw a similar improvement with the 292 Chevy engine when it went from 1bbl to 2bbl because of the points problem and that engines cam duration was so very mild. On the other channels guys who did the 300 six with the 1bbl carb saw a huge gain with the 2bbl, a 71 hp gain with a 625 cfm Demon 4bbl verses the big YFA Carter 1 bbl. The 400 M is exactly the same case..
@@richardholdener1727 I watched every thing you did. The 500 Holley # 4412 was not a standard high Restriction 368 or 424 CFM 2bbl. So a 4bbl wouldn't have been much different..I saw 267 HP, then 300 HP gross on your test. Again,.agree. But a stock 1.23 Motorcraft takes off another 30 hp gross. So you would have seen 237 HP with it. That's what Power Games saw in Australia with the stock 2V carb verses the 4bbl in the 351C. Have a go yourself. The stock 368 CFM 1.23 Motorcraft 2bbl was Way,.Way more restrictive. Back to the 292. 145 hp gross stock. Then 165 hp gross with every.carb you could throw at it. But unlike a Ford 300 or 400 M, that Chevy 292 engine didn't have an over scavenging 268 to 272 degrees of at lash exhaust duration.
@@rotaxtwin On the base 351w , 351m and 400 , it was actually just a Motorcraft 1.21. That's 402 cubic inches serving 2.2998 sq inches of Venturi area. Exactly the same vacuum as a 250 six with a YFA 1.33 1 bbl. I think the 300 may have been even more restrictive, but it only reved to 4000 rpm, the 250 reved to 5000 rpm
30 Years ago I built a Ford 400 with closed chamber 4V heads and intake w/spacers....And because it was going into a 4x4 Pickup, I didn't go crazy on the Cam, it had a bunch of lift and not a ton of duration (it was a custom cam and I don't remember the numbers), I would say that whatever the 351C-4V lacked in Bottom End (because of the huge ports) the extra 50cid of the 400 made up... That really should have been a "Factory Option" in 71 when the 400 came out... Made that Turd Really Move!
Richard what i do here in oz is when building 351 Cleveland here . Using flat top pistons . I used 2v open chamber heads but install 4v valves So comp ratio is around 9.5 to 10 .. so you get abit better air flow . So not over killing compairing the big 4v ports for street use
@@rebekahm4919 many will disagree with the 4V valve in 2V head, but I'm convinced that it would be better in a 351 and bigger. If you take care of shrouding, it would definitely be a plus over the 2V size. One argument is that going bigger makes a mess of the short turn, but in my opinion, people place too much emphasis on getting that right when the amount of flow going around that vs the long side is minimal anyway.
@@gergatron7000 you will be very surprise in the effect . On the 4v valves in a 2v . But understand what you are saying too . But have 3 cleveland now with that set up and all work a treat
4V has a higher port efficiency, provides better cylinder filling, therefore more torque. It might happen at a higher rpm, which would make the 2V feel more "torquey" down low.
An ls with 205cc port volume creates how much power and torque. Lykins built a 351c with iron 4bbl heads 632hp at 7k rpm. My question for Richard is, if you boosted a 2v head on any 351c build what would be the dyno #'s
Thoght this would be about Cleveland's but I guess not. B&A made the Clevor manifolds. To use 351M manifolds on 4V heads on the stock block you need half inch thick spacers on the manifold face and quarter inch valley cover between them. They can be made at home with a router and drill press. You'll also have to notch the front of the manifold to clear the distributor and slot the manifold bolt holes except the four center bolts. Works quite well. To use the dual plane RPM Air gap it takes a one and a half inch thick spacer but wierdly when you raise it up the original bolt holes line up with the head bolt holes. The front has to be notched for the distributor and holes drilled and tapped for the four center bolts and shorter bolts to hold the spacer to the head and the manifold to the spacer. Also can be done at home with a router, drill press and saw to cut the flat bar. Also works well. Typical 2V heads can be ported to 250 CFM @ .550" lift fairly easily and 275 if you're willing to risk hitting water. That's using a 2.08" valve. Exhausts make 220 CFM with the stock valve size. According to Ford in the 70s the so called open chamber head was made larger solely to lower compression and they claimed no difference between them as far as function. I have run 11 to 1 compression on 87 octane without issues. Most people run way too much advance. Never use more than 28 degrees total intial and mechanical combined. Ask the FE guys, they do the same to run high compression. With a 225 @ .050" duration cam you will rev to 6000 RPM in a 400 and 6400 in a 351. When you go above that you will lose a lot of torque below 3000 RPM. Use 108 to 110 LSA and the duration you need to get the RPM you want. For stock head flow 2Vs run 190 to 200 intake and 4Vs run 270 to 300. Thats with stock valves and basic rebuilder three angle valve jobs. Oddly the 4V actually has much better low lift flow than the 2V. Hope this helps answer some questions. Cheers.
I have what may be an unpopular opinion of the Cleveland ports.... Just to be clear, I'm a Ford guy and I own a Cleveland. So... Ford was compromised by the head bolt layout. If you look at a 2V or 4V head in plan view, you see that the port starts central to the cylinder and curves towards the intake valve to one side, pointing the flow at the cylinder wall instead of into the chamber. Now take the ports on a BBC, which for whatever reason, siamesed the port inlets but not the valve layout. So 4 ports curve in the wrong direction, but the other 4 are right. There is something like 20cfm difference between the good and bad ones. Now think of the Cleveland as having all 8 as the "bad" ports on the BBC. They point the wrong way because the port needs to get past the pushrod, then the head bolt boss. The only way to go here is slightly diagonal towards the cylinder wall. The ultimate design would be to mimic the "good" ports on the BBC, which GM actually did on their experimental SBC canted valve head. They achieved this because SBCs have 5 bolts around each cylinder, vs Ford's 4. The difference is clear as day (look it up). Imagine if Ford wasn't encumbered with that head bolt layout...
The bbc is about the poorest example of a good port. All modern performance heads mimic the Cleveland layout especially the prostock drce head. The symmetrical design of the Cleveland contributed to at least 35hp gain over engines of the same size of that era in terms of modding.The Cleveland as well as most ford engines had a bad turn down on exh side but even that wasn’t much of a issue. I know guys that have hit 640hp with a untouched 4v head.
Study the modern NASCAR Cup series and Xfinty series engines, all brands, and you will see how the evolution of the FORD Cleveland race engine influenced todays NASCAR engines, not the BBC. sorry. Don't get me wrong, the BBC is a great engine with an incredible history of it's own. Also the best stock Cleveland head is the Aussie 2V closed chamber, IMO.
@@FordRanchero289 I think the ultimate example of my theory is one that actually went into production (and I completely forgot about it), is the Vortech 8100. It's everything wrong with the BBC porting finally fixed, with the ports all pointing into the middle of the cylinder. Granted, they weren't a high-performance engine, and had tiny ports for the displacement, but I'm sure that the VE was good within the constraints of cost, emissions and efficiency, etc.
As a dumb high schooler I helped a friend install a huge cam, intake, and carb. We thought we knew better than the engineers and ran the rockers loose so we could get the lift out of the cam with no bind....see where this is going??? Lol it ran...it ran good! None of us could get around the car. His valve guided were quickly wiped out and it looked like a chainsaw when he jumped on it😂
@@cliffturner5086 nobody knew the value of a good quench design, and they do need a bit of specific knowledge above your usual porting skills to make good. Even at that, their limitation is the flatline above 0.500" lift. There's no point in opening the valve any further than that, even on the absolute best ported examples (Pavtek CNC, etc). They all hit that limit. In contrast, 4Vs keep flowing more all the way up to 0.8"
I raced the Ford 351C on the dirt tracks of Northern California for 11 years - 1984 thru 1994 - Over the years I used every stock Cleveland head made by Ford, 4V closed, 4V open, 2V open and the Aussie 2V closed chamber heads. The Aussie heads were the best by a mile, more torque and more H/P. We competed in the Hobby/Street stock class. (We had 25 feature wins) Had to run a 2V carb limited to 500cfm (Holley 4412). The cam had a .625 lift - 108* LSA (flat tappet) can't remember duration. Ran the cam advanced 2 or 4 degrees. AUSSIE 2V's WERE THE BEST!
@@gergatron7000 I have a pressure drop flowbench and my stock OC 2Vs went backwards just after .35 . After mild porting, they hold the .35 peak out past .6 but do not gain anything after about .375
How about a fake boss 302 for the tests? 4v heads and a stock buddy bar intake and then the 2v heads csn use an edelbrock 7129 intake. Same bottom end and cam.
😂14 minutes in before Cleveland was mentioned. How our minds wander... I've always read 2v is better off idle, 4v is better once rpm starts gaining. No idea on cross over, never owned either.
What type of machine work is needed to gain the most performance of the 2V heads? I have a 1971 Mach 1 with a numbers matching C351 2V engine. With an FMX auto trans. I would like to swap the FMX for 4 speed AOD auto trans. Thanks for your help.
Take the multi keeper valves out and change to Manley swirl polished single grove keepers. Have a good 3 angle valve job on the seat. Find a Crane Energizer Cam. 524 lift. It's a single pattern Cam. Delta Cam in Tacoma Washington can grind you a cam. This will really wake up a 2 v engine. Cam has a slight noticeable idle. Jet the carb up a couple of sizes.
The 209 cc port area 206 cfm 2V 400 Ford heads are just like the 4V C9 351 Windsor heads. Those heads are reasonable enough to make great power with solid lifters and adjustable valve gear. They top out, modified at about 480 hp gross. The 400 M 4V open chamber heads are 245 cc at the intake, and basically able to make 460 hp gross with ease before modification with 3 angle valve grinds and nicer stainless valves. The 4V will do everything well at any cam kind. I found the open chamber CJ 351 was a 4V engine that worked great with a tiny 2V 351 hydraulic 256 degree at lash cam with 195 deg lift at 50 thou. There was really no need for the 2V 400 head, but Ford killed that engine to the pount that a 351 W HO in the Crown Victoria s was a more powerful engine. A port filled 4V will eat a 2V 400 head everywhere.
Siiiiick some Cleveland talk!!! Fuck yea. I still have my 1970 mustang with a 408 Cleveland FI with a tko 500 and a locker, thing rips. Aussie heads though.
@@hotrodray6802 hell yea man. Easily the best old school motor I’ve had. And I’ve had quite a few. I built mine and a few others, but the 351c with small port heads and a good 5-6 speed. Thing just eats.
I really wanna see that 2v vs 4v comparison. Richard all your 4v builds seem to make good low rpm torque I'm starting to think everything ive been reading and hearing may not be 100% correct
I’ve read conflicting info. Are the 2v Cleveland heads the same as the later 2v 351m/400 heads? It would be very interesting to see both 2v and 4v heads on a 351c and 400m
Yes it's been done with good results but you will have to make spacer plates to be able to run any performance 4v Cleveland intake on a 400 not to mention making exhaust manifolds / headers as well. Both 351m and 400 are a taller & wider engine then a Cleveland.
Great video Richard! No more LS more Cleveland
MY TYPE OF CONVO!!!! Wish I was here for it. I’ve built 2 Cleveland’s. Amazing engine!
I raced the Ford 351C on the dirt tracks of Northern California for 11 years - 1984 thru 1994 - Over the years I used every stock cast iron Cleveland Cyl head made by Ford, 4V closed, 4V open, 2V open and the Aussie 2V closed chamber heads. The Aussie heads were the best by a mile, more torque and more H/P. We competed in the Hobby/Street stock class. (We had 25 feature wins and one championship) Had to run a 2V carb limited to 500cfm (Holley 4412). The cam had a .625 lift - 108* LSA (flat tappet) can't remember duration. Ran the cam advanced 2 or 4 degrees. AUSSIE 2V HEADS WERE THE BEST! - Engine redline was 8500 rpm. I still have a virgin pair of Aussie 2V heads in my collection.
In 1992 we won 7 out of 20 feature points races at our local track, We were the only Ford competing at our track. The main events started with 20 cars - 19 Chevys and 1 Ford (mine). After that season there was talk of outlawing the 351 Cleveland engine from competing in the Hobby/Street Stock class. Go Figure. I retired from racing after the 1994 season, after 25 years in the business, (the best of times - the worst of times) The tech official used to call me "Mr. Cleveland" to try and get under my skin, it didn't. Proud to race a FORD.
If your into the 351Cleveland engine, check out DragBossGarage on RUclips, a lot of great info there.
thnx-in a flow limited situation like the 2-brl circle track stuff I can see why the 2V might work well
@@richardholdener1727 It wasn't a "might work well" situation back then, it did work well. On the dyno and on the race track the 2V Aussie heads proved to be the best for the 351C on the dirt track. With a 12:1 comp ratio and 115 octane race gas it made 447 H/P using a custom Holley 6425 -2V race carb rated @ 625 cfm. We did not dyno it with the 4412 500 cfm unit (forgot to bring it, opps) Today there are many more heads for racers to choose from for a Cleveland or a Clevor build.
Thank you for all your hard work and dedication to High Performance Engines, sharing with the world what works and what doesn't. Keep up the great work!
@@abcullens2328 did you notice a huge difference between the open and closed chamber heads is it as great a difference as I've been hearing what kind of power were you making?
@@rossgirdeen3247 both worked well, the 4V closed chamber heads had good top end H/P but lacked bottom end torque and the 4V open chamber heads we're the worst, (lowest torque & H/P). The 2V open chamber heads had good bottom end torque but lacked top end horsepower. The Aussie 2V closed chamber heads gave the best bottom end torque and top end horsepower. My blocks were decked to zero. TRW flat top Pistons. On the dyno engine made 447 HP @ 7000 rpm using a Holley List 6425 - 625 CFM 2V race carburetor, stock cast iron 2V intake manifold with long tube headers on 110 octane race gas. Torque was over 500. Yes the closed chamber heads made a big difference for me.
I hope that helps.
Yes I've been reading all the books and articles I can find on the 351c wanting to build a 4v Cleveland the Aussie heads seem to be the ticket though like you said. I wanna run factory iron heads. I know it would be better to just use aftermarket heads.
I continue to love watching your dyno tests and lives, the information you give is a credit to your professional approach. Went over your 400 M vs 302 Test again, 4 years ago. Stock, the 400 M had a tiny carb, with about 9" of Hg Vaccum at WOT with a 368 CFM Motorcraft or 424 CFM 2bbl Autolite. It never got a 500 CFM 4412 Holley that you tested it with. Ford rated the first year 400 M as 265 HP gross stock, but you got 267 HP gross. The FE was rated at around 270 HP gross, so Ford had to make the 1971 debut 400 engine stronger than the 12 year old thoroughbred. Our Australian 351 C gave 171 hp net stock with a stock 2bbl (rated 250 hp gross) and 216 hp net stock (Rated 290 HP gross) with a ThermoQuad. Just a 1978 pre production spec 4bbl iron intake with a Carter ThermoQuad adds 63 hp net on a stock 400 M, making 232 hp net, and drops the WOT vacuum to under 1.5" Hg. The stock 2bbl carbs restrict the 400 M to such a huge degree , it's like the world's most Factory Restrictor plate you can imagine. Exactly like a 250 in line six with a Single Carter YFA carb, 175 cubic inches per 1 sq inch of carb Venturi on each engine. Adding a carb with only 85 cubic inches of engine per 1 sq in of carb Venturi adds exactly 63 HP on a 102 hp net engine. Try it yourself next time you test. You never saw a similar improvement with the 292 Chevy engine when it went from 1bbl to 2bbl because of the points problem and that engines cam duration was so very mild. On the other channels guys who did the 300 six with the 1bbl carb saw a huge gain with the 2bbl, a 71 hp gain with a 625 cfm Demon 4bbl verses the big YFA Carter 1 bbl. The 400 M is exactly the same case..
I ran a 2-brl to 4-brl test on the 400-it was 33 hp (it won't be 67 hp)
@@richardholdener1727 I watched every thing you did. The 500 Holley # 4412 was not a standard high Restriction 368 or 424 CFM 2bbl. So a 4bbl wouldn't have been much different..I saw 267 HP, then 300 HP gross on your test. Again,.agree. But a stock 1.23 Motorcraft takes off another 30 hp gross. So you would have seen 237 HP with it. That's what Power Games saw in Australia with the stock 2V carb verses the 4bbl in the 351C. Have a go yourself.
The stock 368 CFM 1.23 Motorcraft 2bbl was Way,.Way more restrictive.
Back to the 292. 145 hp gross stock. Then 165 hp gross with every.carb you could throw at it. But unlike a Ford 300 or 400 M, that Chevy 292 engine didn't have an over scavenging 268 to 272 degrees of at lash exhaust duration.
9" vacuum at WOT ON A 2 BBL 400? I believe it, I don't think there was a malaise era V8 so choked both on the intake & exhaust as a 400M.
@@rotaxtwin On the base 351w , 351m and 400 , it was actually just a Motorcraft 1.21. That's 402 cubic inches serving 2.2998 sq inches of Venturi area. Exactly the same vacuum as a 250 six with a YFA 1.33 1 bbl. I think the 300 may have been even more restrictive, but it only reved to 4000 rpm, the 250 reved to 5000 rpm
30 Years ago I built a Ford 400 with closed chamber 4V heads and intake w/spacers....And because it was going into a 4x4 Pickup, I didn't go crazy on the Cam, it had a bunch of lift and not a ton of duration (it was a custom cam and I don't remember the numbers), I would say that whatever the 351C-4V lacked in Bottom End (because of the huge ports) the extra 50cid of the 400 made up... That really should have been a "Factory Option" in 71 when the 400 came out... Made that Turd Really Move!
Richard what i do here in oz is when building 351 Cleveland here . Using flat top pistons . I used 2v open chamber heads but install 4v valves So comp ratio is around 9.5 to 10 .. so you get abit better air flow . So not over killing compairing the big 4v ports for street use
@@rebekahm4919 many will disagree with the 4V valve in 2V head, but I'm convinced that it would be better in a 351 and bigger. If you take care of shrouding, it would definitely be a plus over the 2V size. One argument is that going bigger makes a mess of the short turn, but in my opinion, people place too much emphasis on getting that right when the amount of flow going around that vs the long side is minimal anyway.
@@gergatron7000 you will be very surprise in the effect . On the 4v valves in a 2v . But understand what you are saying too . But have 3 cleveland now with that set up and all work a treat
Counterpoint-the 2V port size and flow likely do not need the 4V valve size since that is not the choke point (or flow restriction).
@@richardholdener1727
The biggest choke point is ALWAYS the partially closed valve and valve bowl.... Really choking when it's closed
4V has a higher port efficiency, provides better cylinder filling, therefore more torque. It might happen at a higher rpm, which would make the 2V feel more "torquey" down low.
An ls with 205cc port volume creates how much power and torque. Lykins built a 351c with iron 4bbl heads 632hp at 7k rpm.
My question for Richard is, if you boosted a 2v head on any 351c build what would be the dyno #'s
Thoght this would be about Cleveland's but I guess not.
B&A made the Clevor manifolds.
To use 351M manifolds on 4V heads on the stock block you need half inch thick spacers on the manifold face and quarter inch valley cover between them. They can be made at home with a router and drill press. You'll also have to notch the front of the manifold to clear the distributor and slot the manifold bolt holes except the four center bolts. Works quite well.
To use the dual plane RPM Air gap it takes a one and a half inch thick spacer but wierdly when you raise it up the original bolt holes line up with the head bolt holes. The front has to be notched for the distributor and holes drilled and tapped for the four center bolts and shorter bolts to hold the spacer to the head and the manifold to the spacer. Also can be done at home with a router, drill press and saw to cut the flat bar. Also works well.
Typical 2V heads can be ported to 250 CFM @ .550" lift fairly easily and 275 if you're willing to risk hitting water. That's using a 2.08" valve. Exhausts make 220 CFM with the stock valve size.
According to Ford in the 70s the so called open chamber head was made larger solely to lower compression and they claimed no difference between them as far as function. I have run 11 to 1 compression on 87 octane without issues. Most people run way too much advance. Never use more than 28 degrees total intial and mechanical combined. Ask the FE guys, they do the same to run high compression.
With a 225 @ .050" duration cam you will rev to 6000 RPM in a 400 and 6400 in a 351. When you go above that you will lose a lot of torque below 3000 RPM. Use 108 to 110 LSA and the duration you need to get the RPM you want.
For stock head flow 2Vs run 190 to 200 intake and 4Vs run 270 to 300. Thats with stock valves and basic rebuilder three angle valve jobs. Oddly the 4V actually has much better low lift flow than the 2V.
Hope this helps answer some questions. Cheers.
please see the 400M video
@@richardholdener1727 thanks.
I have what may be an unpopular opinion of the Cleveland ports....
Just to be clear, I'm a Ford guy and I own a Cleveland.
So... Ford was compromised by the head bolt layout. If you look at a 2V or 4V head in plan view, you see that the port starts central to the cylinder and curves towards the intake valve to one side, pointing the flow at the cylinder wall instead of into the chamber.
Now take the ports on a BBC, which for whatever reason, siamesed the port inlets but not the valve layout. So 4 ports curve in the wrong direction, but the other 4 are right. There is something like 20cfm difference between the good and bad ones.
Now think of the Cleveland as having all 8 as the "bad" ports on the BBC. They point the wrong way because the port needs to get past the pushrod, then the head bolt boss. The only way to go here is slightly diagonal towards the cylinder wall.
The ultimate design would be to mimic the "good" ports on the BBC, which GM actually did on their experimental SBC canted valve head. They achieved this because SBCs have 5 bolts around each cylinder, vs Ford's 4. The difference is clear as day (look it up).
Imagine if Ford wasn't encumbered with that head bolt layout...
I see exactly what you're saying now.
Rather than look at what could be, look at what was. A typical SBC Fuelie head flowed near 200 cfm. A 4V Cleveland head flowed 275 cfm.
The bbc is about the poorest example of a good port. All modern performance heads mimic the Cleveland layout especially the prostock drce head. The symmetrical design of the Cleveland contributed to at least 35hp gain over engines of the same size of that era in terms of modding.The Cleveland as well as most ford engines had a bad turn down on exh side but even that wasn’t much of a issue. I know guys that have hit 640hp with a untouched 4v head.
Study the modern NASCAR Cup series and Xfinty series engines, all brands, and you will see how the evolution of the FORD Cleveland race engine influenced todays NASCAR engines, not the BBC. sorry. Don't get me wrong, the BBC is a great engine with an incredible history of it's own. Also the best stock Cleveland head is the Aussie 2V closed chamber, IMO.
@@FordRanchero289 I think the ultimate example of my theory is one that actually went into production (and I completely forgot about it), is the Vortech 8100. It's everything wrong with the BBC porting finally fixed, with the ports all pointing into the middle of the cylinder. Granted, they weren't a high-performance engine, and had tiny ports for the displacement, but I'm sure that the VE was good within the constraints of cost, emissions and efficiency, etc.
Evans coolant works well. Keeps temps consistent and builds less pressure than conventional.
As a dumb high schooler I helped a friend install a huge cam, intake, and carb. We thought we knew better than the engineers and ran the rockers loose so we could get the lift out of the cam with no bind....see where this is going??? Lol it ran...it ran good! None of us could get around the car. His valve guided were quickly wiped out and it looked like a chainsaw when he jumped on it😂
Australian 302 2V Cleveland are the best bang for buck. Hundreds of pairs of 302 Cleveland heads ended up at the tip.
@@cliffturner5086 nobody knew the value of a good quench design, and they do need a bit of specific knowledge above your usual porting skills to make good. Even at that, their limitation is the flatline above 0.500" lift. There's no point in opening the valve any further than that, even on the absolute best ported examples (Pavtek CNC, etc). They all hit that limit.
In contrast, 4Vs keep flowing more all the way up to 0.8"
Thought you ended up with a ridiculously high compression ratio putting these on a 351. Like 13 to 1.
@@guyharrison909 it's more like 11.7 from memory (58cc chamber)
I raced the Ford 351C on the dirt tracks of Northern California for 11 years - 1984 thru 1994 - Over the years I used every stock Cleveland head made by Ford, 4V closed, 4V open, 2V open and the Aussie 2V closed chamber heads. The Aussie heads were the best by a mile, more torque and more H/P. We competed in the Hobby/Street stock class. (We had 25 feature wins) Had to run a 2V carb limited to 500cfm (Holley 4412). The cam had a .625 lift - 108* LSA (flat tappet) can't remember duration. Ran the cam advanced 2 or 4 degrees. AUSSIE 2V's WERE THE BEST!
@@gergatron7000 I have a pressure drop flowbench and my stock OC 2Vs went backwards just after .35 . After mild porting, they hold the .35 peak out past .6 but do not gain anything after about .375
How about a fake boss 302 for the tests? 4v heads and a stock buddy bar intake and then the 2v heads csn use an edelbrock 7129 intake. Same bottom end and cam.
"Clevors" SBFs with C heads were quite the deal... 30 yrs ago.
Gary Roughly from near Ft Smith AR made the intakes.
😂14 minutes in before Cleveland was mentioned. How our minds wander...
I've always read 2v is better off idle, 4v is better once rpm starts gaining. No idea on cross over, never owned either.
What type of machine work is needed to gain the most performance of the 2V heads? I have a 1971 Mach 1 with a numbers matching C351 2V engine. With an FMX auto trans. I would like to swap the FMX for 4 speed AOD auto trans. Thanks for your help.
Aussie 2v heads ported can make good power
Take the multi keeper valves out and change to Manley swirl polished single grove keepers.
Have a good 3 angle valve job on the seat.
Find a Crane Energizer Cam. 524 lift.
It's a single pattern Cam.
Delta Cam in Tacoma Washington can grind you a cam.
This will really wake up a 2 v engine.
Cam has a slight noticeable idle.
Jet the carb up a couple of sizes.
The 209 cc port area 206 cfm 2V 400 Ford heads are just like the 4V C9 351 Windsor heads. Those heads are reasonable enough to make great power with solid lifters and adjustable valve gear. They top out, modified at about 480 hp gross. The 400 M 4V open chamber heads are 245 cc at the intake, and basically able to make 460 hp gross with ease before modification with 3 angle valve grinds and nicer stainless valves. The 4V will do everything well at any cam kind. I found the open chamber CJ 351 was a 4V engine that worked great with a tiny 2V 351 hydraulic 256 degree at lash cam with 195 deg lift at 50 thou. There was really no need for the 2V 400 head, but Ford killed that engine to the pount that a 351 W HO in the Crown Victoria s was a more powerful engine. A port filled 4V will eat a 2V 400 head everywhere.
agreed
Siiiiick some Cleveland talk!!! Fuck yea. I still have my 1970 mustang with a 408 Cleveland FI with a tko 500 and a locker, thing rips. Aussie heads though.
Pretty strong 71C Mustang FB here.
@@hotrodray6802 hell yea man. Easily the best old school motor I’ve had. And I’ve had quite a few. I built mine and a few others, but the 351c with small port heads and a good 5-6 speed. Thing just eats.
I really wanna see that 2v vs 4v comparison. Richard all your 4v builds seem to make good low rpm torque I'm starting to think everything ive been reading and hearing may not be 100% correct
I’ve read conflicting info. Are the 2v Cleveland heads the same as the later 2v 351m/400 heads? It would be very interesting to see both 2v and 4v heads on a 351c and 400m
the 351/400M did use 2V heads
@@cys804 effectively, yes, if you don't count the thermactor bump in the exhaust ports on emissions 351M/400s. This can be ground down though.
It's better to use the M heads. Have hard seats and valves.
The early valves can start to tulip.
GM "cured" that siamesed port design with their Vortec line of Big Block engines.
347 windsor for circuit racing in a 66 mustang, would you recommend 2v or 4v Cleveland heads to make it a boss engine or go with windsor alloy heads?
afr windsor
Thankyou
4v will make more if heads aren't modified
Anyone run 4v heads on a 400?
I have not run iron stock 4V heads but have run aluminum after market 4V heads
Yes it's been done with good results but you will have to make spacer plates to be able to run any performance 4v Cleveland intake on a 400 not to mention making exhaust manifolds / headers as well. Both 351m and 400 are a taller & wider engine then a Cleveland.
If you do make sure you balance the engine.
Those cranks and rods were poorly cast. Lots of junk to clean off of them.
Have you looked at the sbf enforcer heads much
I have a set on a 351w with a custom cam but no numbers