4v/2v 351C questions !

I read in some books and other articles that a 70 mach 1 351c 4V has
4 bolt mains too ? ( like the boss). is that correct ?.. because other
data report 2 bolts...

And also read that a 2v had single exhausts and 4v dual... when it came from the factory Is that correct ?

And last... What carbs are you guys running on a 4v 351c ?.. i have a 600 holley , but have a feeling its a bit small for the heads...


THANKS !

Hi!

The carburator for a 351-4V is a autolite 4300, the 351-2V is factory single exhaust.

and the 351 1970 is 2 bolt main

Ray

600 cfm is nore than enough if you're do only street.
Even the 600 Holley on my 414 cid [351C-4V stroker] is doing OK on the street.
But I never run it above 4000 rpm

If your running the car on a dragstrip or race track it might be different

Hi Ronald

Thanks for your answer, but i do run my engine up to 5500 rpm a lot
( every time i drive it )especialy with the 4.11 gears i have.
I just read a lot of different carb set ups on these 351 engines so i
was/am qurious...

I didnt have time yet to realy go in to the carb and test it and check
its set up, but as an engine builder i just like to see what you guys
use. The 351 engine is pretty new for me , so thats why i ask.
On most mopar smallblock and light hipo bigblock engines we use 770 avengers and the work very well most of the time. But im not sure
indeed if that would go for the 351 too, i think it all depends on the rest
of the set up of the engines individualy. Mine is a rev'er and likes to
eat some fuel. But i wll check it when i have some time ( test it and
do some messurments on fuel/air ,vacuum etc.

It does stall a little at low to high speed drives and i will play a little
with the secondary system and change some nozzles sizes etc.

Thanks again! and all the others... Please report your carb size on your
car too and how do you think it handles and are you satisfied with it.

I can also run the engine with high compression, 12,5:1
I'm using the original 1970 351C-4V heads,
flat-top pistons with small valve pockets
Cam: Crane 272 H10 hydraulic cam KLIK FOR INFO

Premium gas + octane booster [Octane+] from Wynns

1,12.5... Thats high ! for a streetcar...

I see you use octane booster.. but be carefull! that you mix that
correct. Because premium fuel is always given by its max octane
but is often much lower. Also octane booster is a tricky item iff
you dont mix it up right you need alot to get to more than 105 octane
( on 1.125 you would need minimum 105 - 110).
BUT you probably now what your doing

Ps.. do you run an automatic or stick ? ( 4 or 5 ?)

Greetsss

I use Octane 10+ from Wynns, which only raises the number slightly,
using a bottle on a full tank.

I might transfer to an other brand, but they are more difficult to get a hold off.
Yesterday I came accros this website with info on octaneboosters:
http://members.rennlist.com/951_racerx/OctaneBoosterComparison.html

Hi Ronald

Do you drive an automatic car or manual ? and what type...

Greetss

Shelbster wrote:

Hi Ronald

Do you drive an automatic car or manual ? and what type...

Greetss

FMX A/T
3.50:1 axle

I also have used and still have the same holley 600 square bore , (electric choke converted) that was on my 70 351-c 4barrel 4speed, shaker car when I bought it in 1975. It has always been more than enough carb for the car. If you crunch numbers on the many carb sites availiable 600 to 650 cfm come up paerfect for 351 cu.in.
It has a 4-barrel 11.5 quenched chamber heads that it came with and it was initially a 2 bolt main block. Over the years I got a sweet dael on a 351 boss block that was 4-bolt main so I upgraded. I understand that kits are availiable to convert the 2 bolt to 4 very easiely. I wish I would of done more research on that before upgrading as my orginal block is now floating somewhere else in this world.

Bill, Las Vegas Nevada

Well , thats always the case with things like that...

Iff i new what i know now 15years ago... i let go of a collection of shelby's
( 2x 500gt 1x 350 Gt conv.) for 25000$....

So dont be to angry about it..., thats the way these things go

Thanks for your solace . I've been sleeping ok since then as I needed the csah more than the block. It's Like you said "it's just one of those things" I'm 53 now so I've done "other" dumb things before and since. Like in the 70's when I bought Gene Rodenbery's (star trek fame) 66 Mustang coupe for $200.00 just to gut the 289 out for my 66 ranchero and then let the mustang get towed for crushing!

Happy holidays, Bill Las Vegas Nevada

Like was posted, '70 and '71 351C-4V blocks have 2 bolt mains.

Ford did start using 4 bolt main blocks for 4V Cleveland's in 1973 (and maybe in 1972?). All '73 4-barrel Cleveland motors came with 4 bolt mains. That might be what you read. The '73 version of the 351C-4V had less compression and a slightly hotter hydraulic cam. I think Ford refereed to it as a 351 "Cobra Jet" but its just an open chamber 4 barrel Cleveland with a 4 bolt main block.

Sorry for my English. Excellent  discussion forum. This is a complicated subject and the changes disservice 351 engine operation.
Mine is a 351 2V cleaveland but that will change the original manifold for Edelbrook four barrel and place a Holly carburetor 600. I commented that at high speed (5500 RPM or more) the car works fine, but in low car runs out and have a few seconds of interruption. Also change some of the injectors but the result has always been worse ...