351C 4V "quirks"

As some of you may know I have inquired here regarding a few special issues/quirks of the 351C 4V. And this is in regard to a very stock rebuild not to exceed about 5700 rpm.

This is what I believe I now understand:

1. Front cam bearing should have no more than a .003-.005 setback from the front of the block.

2. Stock valves need to be replaced due to their weakness in stock form.

3. The stock 4V heads (63cc closed chamber) should not need any porting or extra machine work.

4. A Cleveland specific thermostat should be used if available.

I do not want to rehash any of the 4 points listed above and have really learned more than I thought I would on these 4 items. I paraphrased these 4 points in the interest of brevity.

What I am really after now are anything that has not been mentioned above that is different for a Cleveland motor than for other engine rebuilds. It seems like the Cleveland is quite an onion and the more I look into the quirks of the motor, the more is uncovered.

What else could there possibly be that is specific to the Cleveland engine?

Thanks in advance to all who respond.

Jeff-

The only other things I can think of is that if you are going to drive it in colder weather then use the "turkey pan" and do not block the cross over passages in the head. This will make it much more polite on cold starts.

If you still have to install the intake use RTV on the end seals instead of the gaskets so you will not have to do it over when the seals squish out or split.

Do not use to big of a carb. Most of the time a 600 cfm holly is perfect for a street car.

Along with the valves replace the rod bolts and nuts. ARP's are cheap insurance and most of the supposed OEM valve failures were actually rod nut failures.

If you can not get 93 octane or do not want to add octane booster every time you fill up consider using a thicker head gasket (or double the gaskets up) to drop the compression a bit. Google it for opinions. Cometic's are good. You will be at around 10.7 to one with your heads. With a thicker Cometic you can get it down to around 9.7 to 10 to one.

That is about it. I will probably have an "oh yea that as well" moment later on. If I do I will be back.

- Paul of MO

My $.02:

-Don't use a high volume oil pump, if anything, use a high pressure spring, only.

-Do use grooved main bearings (upper half is sufficient but some builders prefer upper and lower)

-Do use a double row timing chain & sprockets

-Do use a degree wheel to verify cam timing

-Verify the valve covers have drip tabs (above each rocker) or that the rockers have the stamped tabs installed under each rocker bolt. (assumes stock stamped rockers)

-Don't use umbrella seals on the valve stems...go with the perfect circle style that has a teflon wiper. (this is not at all specific to a cleveland)

My $.02:

-Don't use a high volume oil pump, if anything, use a high pressure spring, only.

-Do use grooved main bearings (upper half is sufficient but some builders prefer upper and lower)

-Do use a double row timing chain & sprockets

-Do use a degree wheel to verify cam timing

-Verify the valve covers have drip tabs (above each rocker) or that the rockers have the stamped tabs installed under each rocker bolt. (assumes stock stamped rockers)

-Don't use umbrella seals on the valve stems...go with the perfect circle style that has a teflon wiper. (this is not at all specific to a cleveland)

Click to expand...

I agree with NOT using a high volume pump - do not change the spring.

Everything else is OK except for the NEED for the grooved bearings. This will not hurt anything but not needed on your engine.

- Paul of MO

You might want to put a safety chain on the front of the engine in case the motor mount lets go so other things don't get screwed up.

David

I agree with NOT using a high volume pump - do not change the spring.

Everything else is OK except for the NEED for the grooved bearings. This will not hurt anything but not needed on your engine.

- Paul of MO

Click to expand...

Mystic Fish,

If you have a choice when you're buying mains, get the grooved uppers...they improve oiling to the rods on a cleveland.

You can google every suggestion I made and make your own decision.

Best regards with the build,

BT

i use the cam bearing restrictors or restrictor cam bearings . this forces more oil to the other areas and i have never heard of anyone having a cam bearing failure in any car when restricting flow to the cam . many stock clevelands had premature main and/or rod bearing failure.

half grooved bearings as i mentioned in your previous post and as basstrix suggested because it increases the length of time that oil is supplied to the bearings and there is ZERO down side to using these and only an upside because the main force on the bearings is on the bottom half where the full bearing supplies full support and full area fr the oil wedge to form.

high pressure 60 psi spring . the one that comes in the mellings pump is 47 psi . this will not wash your bearings out or break a high perf oil pump drive or the distributor gears . you will occasionally be spinning it higher than a stock cleveland therefore it is logical to use a higher pressure spring as basically free insurance.

high perf oil pump drive so it doesn't break.

.016" holes in both oil galley plugs to increase oil to distributor gears, cam chain and cam thrust plate.

disassemble the oil pump and insure the bypass valve moves freely . hone the bore with a ball hone if necessary.

increasing the quench distance with thicker gaskets promotes detonation . quench should be between .043 and .034 with closer to .034 being best . if your compression is to high, you can get custom dished pistons that mirror the combustion chamber so you retain the quench.

.

One thing I didn't see mentioned, I've heard about guys having a lot of issues with aftermarket brand rear main seals leaking. I'd hate to see you get that thing in the car and soon after have to take it out to fix a rear main seal leak. From what I've read, go with the fel-pro rear seal. Unfortunately I think it's an obsolete part.

One thing I didn't see mentioned, I've heard about guys having a lot of issues with aftermarket brand rear main seals leaking. I'd hate to see you get that thing in the car and soon after have to take it out to fix a rear main seal leak. From what I've read, go with the fel-pro rear seal. Unfortunately I think it's an obsolete part.

Click to expand...

good point . i think that cometic sells it or sells a similar one . the better seal is the red one.

Grooved bearings are to assist in getting more oil to the rods...... they actually decrease the amount of oil in the mains which is logical because there is less bearing surface area.

A quote:

"It’s essential to understand that bearings depend on a film of oil to keep them separated from the shaft surface. This oil film is developed by shaft rotation. As the shaft rotates it pulls oil into the loaded area of the bearing and rides up on this film much like a tire hydroplaning on wet pavement.

Grooving in a bearing acts like tread in a tire to break up the oil film. While you want your tires to grip the road, you don’t want your bearings to grip the shaft, so grooving is bad for maintaining an oil film."

I will post up the source after we are told how stupid this statement is.......

So... You do not need funky grooved bearings. Extra cost with no actual value.....

This comment is not directed towards BT. He is OK and I enjoy his posts.

Paul of MO

I have temporarily closed this thread until further notice once a specific concern is discussed and addressed by the staff. Please do not PM me or other staff members about this.

The discussion on main bearings is interesting here. Each side's opinion is correct. Using fully grooved main inserts will increase the oil flow to the rods as it delivers 360 degrees of oil supply, however, doing so diminishes the load carrying surface area where the most loading is...on the lower half of the bearing in the main cap. So how to keep everyone happy?

Modern engines, or, most modern engines today utilize what is called a "3/4 groove" main bearing set. They are used on domestic and import engines today. For your 351c, Sealed Power offers a competition main bearing set, called their "M" series, 146M to be specific, that not only is made with a performance material, but has full grooving in the upper shells as is normal, but continues the groove, tapering off, into the lower shell. These main bearing sets deliver the best of both worlds, maximum oil availability with full load carrying surfaces....and Sealed Power sells these performance sets for most popular engines, even the 427 FE. Check them out.