2v vs 4v 351 cleveland
Printed From: The Ford Torino Page
Category: Powertrain Specific Forum
Forum Name: 335 Series Engine Forum
Forum Description: 351C, 351M and 400 engines
URL: https://forum.grantorinosport.org/forum_posts.asp?TID=8052
Printed Date: 26-March-2026 at 5:42PM
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: 2v vs 4v 351 cleveland
Posted By: upfish
Subject: 2v vs 4v 351 cleveland
Date Posted: 25-October-2012 at 4:48AM
| What is better 2v or 4v. |
Replies:
Posted By: Rockatansky
Date Posted: 25-October-2012 at 1:24PM
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depends upon what you're doing with it. it's true that 2V's flow better at low valve lifts than the 4V's, but with a well chosen camshaft the 4V's will do everything the 2V's can & then some
then again, a well chosen 2V build combo can walk all over a poorly chosen 4V combo. it's easy to dog out a 4V with a cam not suited for the combo
... then there's 3V ------------- 72 GT Ute |
Posted By: lynchster
Date Posted: 25-October-2012 at 3:13PM
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If you're on a budget and already have the 2V heads go with it. The 2.05 intake valves are still bigger than the 2.02 valves offered in GM's small black hotrods and the heads will flow plenty for a street car.
I'd ditch the stock valve train though. The factory 2V rocker arms are weak and the valve heads are prone to becoming shrapnel. ------------- Chuck 72 Gran Torino Sport 13 Taurus SHO "Mr Pig" |
Posted By: Rockatansky
Date Posted: 25-October-2012 at 3:27PM
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yes the stock Ford valves need to go into the garbage can and replaced with 1 piece stainless
the factory 2V rocker pedestals are aluminum, 4V were steel. if buying new replacements you want to make sure you're getting steel fulcrums ------------- 72 GT Ute |
Posted By: Rockatansky
Date Posted: 25-October-2012 at 4:09PM
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also, 2V castings with a casting code starting with D5xx(1975) will not perform like earlier 2V castings. the D5 heads have a redesigned water jacket that chokes the exhaust port, the head can't breathe. D5 heads will probably have different valve spring hardware that severely limits how much cam lift they can handle, even the smallest aftermarket cams are too big unless you change the retainers(along with the garbage stock valves) ------------- 72 GT Ute |
Posted By: unlovedford
Date Posted: 26-October-2012 at 1:32AM
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Interesting. I have that stuck 351 2V engine in the yellow '72. I was thinking of just scrapping it for the weight, but perhaps I should hold onto that engine for a future build? Maybe the cam choice is one of the issues with my 4 speed car just not feeling as it should. ------------- Joe 1972 Mom's Squire Wagon 1972 Torino Wagon 1976 Torino 1968 Cougar XR7-First batch 1972 Torino 460 1989 BroncoII/Jeeps/Titanimous Popeye and Brutus (Rams) |
Posted By: Rockatansky
Date Posted: 26-October-2012 at 3:59AM
Hal no don't  scrap a Cleveland block if it ain't busted!
Q-code = 351C & baby C6
 or toploaderwhat cam is in it, do you know? what about the rest of the combo, intake/carb, exhaust, rear gear ------------- 72 GT Ute |
Posted By: unlovedford
Date Posted: 26-October-2012 at 4:08AM
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Unsure of the cam, 3.25 rear gear, 4 speed, Edelbrock dual plane intake, Demon carb, stock exhaust manifolds, 2.5 inch pipes, Flowmasters. The 2V engine is 118K stock and stuck. Probably running an FMX and has 3.00 gears. That car will get a 5.0 or 5.8/5 speed combo to just play with. ------------- Joe 1972 Mom's Squire Wagon 1972 Torino Wagon 1976 Torino 1968 Cougar XR7-First batch 1972 Torino 460 1989 BroncoII/Jeeps/Titanimous Popeye and Brutus (Rams) |
Posted By: colonelsandersman
Date Posted: 26-October-2012 at 3:32PM
| There's a great episode of Horsepower on powerblock tv where they build up both 351w and 351c. They then dyno the Cleveland with 4v then with 2v heads. They show the chart and explain the difference between the two. Really top notch show. |
Posted By: Rockatansky
Date Posted: 26-October-2012 at 6:58PM
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well, it was better than not having a show including the 351C but it was a little disappointing
actually they built a stroked Clevor and a 351C 2V/4V, with the 351W factory heads it could not have even competed with the 351C-2V, and i don't know what they did to tank the 351C-4V but they did it. for the 4V heads not to take off like a rocket from where they begin to surpass the 2V heads on the graph... something was going on. i'm sorry if i go all conspiracy theory here but all i can think of is that they started killing cylinders on the dyno? there's nobody paying advertising dollars to show that the factory heads still kick S after all these years, but there is $ for stroker parts, alloy heads & clevor intake manifolds
can you call a 351C with small 2V intake ports a 4V? maybe in Aus but not on my street. being a single plane intake was probably also a stumbling block, if the build wasn't 'enough' to allow a 4V Cleveland to crank out, it should not have had a single plane intake on it. it was a piss-poor combo & who ever picked the C parts or allowed them to be used should be
 fired... but as i said i suspect maybe a little more was goin on, it shoulda ran better than it did, even with the small intake ports & 'chevy' cam here's a build! and it was still climbing HP when they cut the throttle
http://www.youtube.com/watch?v=1zk6jO5vXHc" rel="nofollow - http://www.youtube.com/watch?v=1zk6jO5vXHc
http://www.youtube.com/watch?v=zqn-jy35SaM&feature=relmfu" rel="nofollow - http://www.youtube.com/watch?v=zqn-jy35SaM&feature=relmfu ------------- 72 GT Ute |
Posted By: 1zebra3
Date Posted: 26-October-2012 at 8:52PM
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I would go with the 2V heads. Back in the day (mid 70s ) I had one in my 70 mustang that I bought so I'm not sure what the guy had in it. Holly 2V ,aluminum dual plane manifold,polished intake & exhaust W 3 angle valve job, cam & valve train ? dual point dist, accell ignition, headers, 4 sp & 4-11 rear gears. Couldn't keep rear tires on it. Kick many camaro, cudas & challengers asses. Too many drag racing tickets so I sold that engine and went to 351w that wasn't quit so mean. DAMN!!! ------------- 1zebra3 76 S&H Torino 70 mustang MACH 1 73 MACH 1 79 F-350 (SOLD)DAMN 89 STANG LX COUPE 04 F-150 |