Ford Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hello to all, I'm new to your forum and glad to have found you guys. You being mostly Aussies (Yes, I'm a Yank) here makes it even more interesting. I just picked up a Clevo to rebuild w/ my son to put eventually in a '85 F-150 4x4. It's kind of a weird duck. It's a 2 bolt main w/ 4V OPEN chambered heads, flattop pistons and an intake that accepts the spreadbore Autolite 4300 carb. What's the comp. ratio for that setup?? Also, someone has punched a hole at the distributor end of the lifter valley about an inch wide I would guess to drain the valley quicker. Will that also drain the valve covers if they fill? Does this "hole" idea sound advantageous or dumb? I want to address the oiling problem completely w/ this motor, any additional processes besides a higher volume pump? Thanks in advance.
 

·
Registered
Joined
·
1,373 Posts
Welcome to the forum. With regard to Clevo's oil issues there's been a bit of discussion here lately so suggest you do a search. Some people reckon there aren't any issues, I kind of agree, oil restrictor kits are only necessary if it's a real high revver. So just use a bigger sump and a higher volume oil pump. Guess you can't do much about the hole in the valley so living with as is will be fine also I'm sure.

Compression wouldn't be too much with open chamber heads and flat tops - guessing around 9.5:1 - but I'm no expert there. There's been some great improvements in camshaft technology in recent years, so highly recommend you consult with the best people out there before you choose one. You can get some big gains in low down torque with the 4V Clevo's nowdays which will be an advantage for a 4x4. Traditionally people have experienced average low end performance with 4V Clevo's - compared to SBC - but most of that was wrong camshaft choice. Those heads are big and can be improved upon with the right camshaft. Check out comeracing.com for some expectations with Clevo performance.

Me much prefer the square bore inlets to suit a Holley pattern.
 

·
Registered
Joined
·
661 Posts
welcome to the aussie forum old iron.the hole you are referring to is cast that way in all clevo blocks to allow oil to reach dizzy and cam gears etc.the 351 you have is great but take this into consideration.an F150 is a heavy piece of gear which i,m guessing would weigh in excess of 4000 pnds.what you need is an engine that will build masses of torque to get all that weight moving.here is my suggestion.4v heads are not known for their low end torque producing capabilities so offset some of the cost by selling your 4vs and doing a set of open chamber 2vs with a mild cam , comp cams 260 or 268 for example.as far as oiling concerns go i would say with a combo like this you should not have any ,even the idea of a hi volume pump seems like overkill.put a large capacity sump on it and deburr the block internally to aid oil drainback.
 

·
BSR Twin System (tm)
Joined
·
4,751 Posts
The 4V Open Chamber Heads are off a 72 351 HO. As far as I know, that was the only year they were offered. I can't remember the Compression Ratio.
 

·
Registered
Joined
·
227 Posts
Here are the head specifications that you could have, could be either compression depending on head gasket, valve reliefs, deck clearance etc

351C HO
yr 72
cc 75.4
Compression 9.2:1

351C-4V
yr 72-73
cc75.4
compression 9.0:1

yr 74 351-4V
cc 78.4
8.7:1
 

·
Registered
Joined
·
13 Posts
Discussion Starter #6
Thanx much for the inputs. I realize the heavy F-150 will not be a good match unless I don't mind the smell of burning clutch facing, but it is a bolt up deal and I don't have room to add another car to the "fleet". Here in California I have to go back 30 yrs to have a smog legal car. Mustangs, Fairlanes, Falcons, Mavericks, Comets would work. A U.S. '64 Falcon Sprint would be very nice.
This Thurs. the block, heads, crank & pistons go to the machine shop for measureing and magnafluxing. This motor has resided in the weeds w/ one head off for at least a yr. so wish me luck.
 

·
Slurry Boostin
Joined
·
1,211 Posts
Not trying to hi-jack the thread, but on a similar topic, obviously deburring the block helps return oil to the sump quicker and what have you, but the oil drain holes in the valley, has anyone ever enlarged them, or drilled more?

I've de-burred my block, and was considering drilling these out some more, or drilling two more holes, but didn't know if it would affect the strength heaps.

Any input anyone??
 

·
Munch Munch Rice 4 Lunch
Joined
·
594 Posts
i've been told that drilling a few more holes in the valley to help oil the cam a bit more can be done, couldn't hurt.
you only have to look at modern engines, the little japanese 2litre engines and the such are running and using 4.5 litres of oil and have half of the components to lubricate.
 
1 - 8 of 8 Posts
Top