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Chevy spec motor vs Ford horsepower

Posted: Fri Nov 10, 2017 7:28 pm
by rdkonkel
We run a spec class and this year one competitor won every race with a ford. Everyone else is chevy.
Rules are
9:5/1 compression
Stock or s/r head 75cc minimum chamber
No cam lift rule, no roller cans
Any 4 barrel Holley
Headers

Now I know the Ford 351 stock replacement style World,Dart,etc are 62-65 cc and require a dished piston. So I’m wondering if the Ford head is just that much better than the chevy or what am I missing? His motor left everyone in the dust.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 12:23 am
by John Haskell
Ford SB wedge & canted valve heads have a superior port bias over the Chev head. That's about the only thing.

Ford never had a short turn worth a crap compared to the Chev & the wedge port volume was crap too.

Stock Cleveland open chamber heads can be changed around to reach 75cc. Make roughly the same power as a closed chamber head to about 500 hp. There real good if valve lift stays at .525 lift or so. Overlap sensitive. LCA wider than wedge.

GM did use the same bias only right hand, on the 69-72, 472 / 500 Cadillac & they ran like stink for what they are.

It took forever for GM to figure it out I guess. Now you have the LS head. They use the right hand Cadillac bias & they also run like stink !

Ford bias goes left where Chev LS goes right. Same thing only backward. They had to do it that way or they would have been teased forever. It's about exactly the same degree as Ford.

Take a look at the BB Chev. What they call the bad intake port has the port similar to the Ford. It measures lower on an air bench but, it's called the power port & proven so, due to the port bias they used.

About sure they didn't realize that back then.

Get an LS head & it's over for the Ford. Ford doesn't have current development & never will.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 12:50 am
by In-Tech
rdkonkel wrote:
Fri Nov 10, 2017 7:28 pm
We run a spec class and this year one competitor won every race with a ford. Everyone else is chevy.
Rules are
9:5/1 compression
Stock or s/r head 75cc minimum chamber
No cam lift rule, no roller cans
Any 4 barrel Holley
Headers

Now I know the Ford 351 stock replacement style World,Dart,etc are 62-65 cc and require a dished piston. So I’m wondering if the Ford head is just that much better than the chevy or what am I missing? His motor left everyone in the dust.
Was it a 351n head? :mrgreen: cuz, yeah, all over but the cryin. :lol:

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 2:42 am
by englertracing
John Haskell wrote:
Sat Nov 11, 2017 12:23 am
Ford SB wedge & canted valve heads have a superior port bias over the Chev head. That's about the only thing.

Ford never had a short turn worth a crap compared to the Chev & the wedge port volume was crap too.

Stock Cleveland open chamber heads can be changed around to reach 75cc. Make roughly the same power as a closed chamber head to about 500 hp. There real good if valve lift stays at .525 lift or so. Overlap sensitive. LCA wider than wedge.

GM did use the same bias only right hand, on the 69-72, 472 / 500 Cadillac & they ran like stink for what they are.

It took forever for GM to figure it out I guess. Now you have the LS head. They use the right hand Cadillac bias & they also run like stink !

Ford bias goes left where Chev LS goes right. Same thing only backward. They had to do it that way or they would have been teased forever. It's about exactly the same degree as Ford.

Take a look at the BB Chev. What they call the bad intake port has the port similar to the Ford. It measures lower on an air bench but, it's called the power port & proven so, due to the port bias they used.

About sure they didn't realize that back then.

Get an LS head & it's over for the Ford. Ford doesn't have current development & never will.

??
Ford doesn't have the development?
Yates d3 and c3
CHI heads
SCM
Blue thunder

Not only that, bitchn aftermarket Chevy stuff has raised cams, and large cam core diameters like 55mm

Fords cams are already up out of the way and are 52mm to begin with....
It's just a shame the blocks were weak we wouldn't have had such an unbalanced aftermarket

https://youtu.be/oJRMLfrlPvg
Sure looks under developed to me....

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 8:04 am
by ZIGGY
Maybe the guy's just a better racer...

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 12:36 pm
by Racerrick
John Haskell wrote:
Sat Nov 11, 2017 12:23 am


Get an LS head & it's over for the Ford. Ford doesn't have current development & never will.
LOL spoken like a true Govrnment motors libtard. Call me when GM produce anything that even comes close to the engineering in a Ford GT. GM never will and never has built anything that even comes close. FACT.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 2:06 pm
by englertracing
Racerrick wrote:
Sat Nov 11, 2017 12:36 pm
John Haskell wrote:
Sat Nov 11, 2017 12:23 am


Get an LS head & it's over for the Ford. Ford doesn't have current development & never will.
LOL spoken like a true Govrnment motors libtard. Call me when GM produce anything that even comes close to the engineering in a Ford GT. GM never will and never has built anything that even comes close. FACT.
Yes it's more like GM got a Ford head.... and called it an ls7, but for an ls7 to stay with a full aftermarket clevor, it needs a Cleveland head, they are calling those an LSR head

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 2:27 pm
by rdkonkel
ZIGGY wrote:
Sat Nov 11, 2017 8:04 am
Maybe the guy's just a better racer...
Easy to be better if you have a bunch more power in a limited class...

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 2:44 pm
by englertracing
Can you do something with Cleveland heads?

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 3:16 pm
by Steve.k
Im thinking this is dirt track or oval. Here where i live the Cleveland is banned from every class. That pretty much leaves the n head. If they allowed the puny cleveland 2v there would be some sad faces. The n head is a pretty serious head on its own.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 3:23 pm
by CamKing
If they allow the 351N head, it's a ton better then any iron chevy head.
If you're limited to stock rockers, The Ford has a ratio advantage.
If you're limited to stock diameter flat tappet lifters, the Ford has a diameter advantage.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 6:45 pm
by rdkonkel
Rules allow chevy’s the dart s/r head 75 cc with the small ports. Fords can’t run the N heads.
What I’m wondering is if the chevy 350 is at a disadvantage vs a 351w for torque/hp.
Ford can have the world s/r head.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 6:45 pm
by rdkonkel
This is for dirt track limited motor class.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 7:02 pm
by 340king
Depending on the weight rule, if it is a light car I may know the reason, the Ford engine builder has several choices of displacement. Do you know for a fact that the engine was a Windsor block engine? Can the class have strokers? I have a lot more questions than answers at this point.

If this is a light weight class, then a 302 based engine would have an advantage over the rest of the competition with a much lighter engine. This means more rear weight and that is typically an advantage. If there isn't an RPM rule, the 302 based engine can make up for lack of HP by gearing deeper and gaining a mechanical advantage. If they allow strokers, then you can get close on HP and still be much lighter. Handling is worth a lot of HP in many classes.

Re: Chevy spec motor vs Ford horsepower

Posted: Sat Nov 11, 2017 7:18 pm
by Steve.k
So you figure like a 347 stroker deal? Could be and the 69 iron Windsor head can make decent power also.i know the 347 seems to make most heads work better.