351C 4V Valve and valvetrain replacement

[Mystic Fish]

I am helping Cobra2572 rebuild his 71 Mach 1 351C 4V and want some advice on the stock valve train/heads.

The block is at the machine shop getting bored .030 over and the engine kit has been purchased. The pistons are Sealed Power L2379F30 forged pistons that show 10.76:1 compression ratio with 58.6 cc combustion Chamber heads. I believe the closed chamber heads on the 71 4V are actually 63 cc's, so the compression will be slightly reduced. The Camshaft is an Erson cam part number E220221 hydraulic flat tappet unit. Advertised lift is .536/.536 and advertised duration is 310/310. Lobe separation angle is 114 degrees. The @ .050 numbers are .310/.310 lift and 226/226 duration. Intake centerline is listed on the cam card at 106 degrees.

I am of the opinion that the valves need to be replaced due to the weak nature of the multiple groove locks and 2 piece valves. When we tore down the engine, the intake valve in cylinder 2 was broken. In addition to new valves, I believe hardened exhaust seats should be installed.

Now the questions...

Are the stock springs good enough for the camshaft that we have or should they be replaced? The specs on the cam card recommend springs with 110 lb seat pressure and 250-280 lb open pressure.

Should all of the valves be replaced or just the broken or damaged ones? Heads have not been torn down or inspected yet.

Should hardened seats be installed?

This will be a street only vehicle and is a 4 speed car. My friend Cobra2572 (Dave) wants a close to stock rebuild with a slightly hotter camshaft which is the reason for the camshaft that was purchased.

Since I have no experience with 351C Engines I would like some feedback on this. My real experience is 383 and 440 Mopars.

 

[OMS]

I would replace all the valves

I would get a matched cam / lifter / spring set

Since you already have the cam, you might not be able to get a matched set

I would replace the springs

 

[Omie01]

The only down side to a Cleveland head is the amount of work they need for performance. With your build you will not have to go to screw in studs, but I feel single groove lock valves, and hardened exhaust seats are always worth the investment. I would never use stock springs on any new cam unless you are SURE of their quality and stats. Make sure to switch to steel fulcrums for your rockers if you stick with the stamped steel units. Good Luck, and have fun!!

 

[Qcode351mach]

I would replace all the valves

I would get a matched cam / lifter / spring set

Since you already have the cam, you might not be able to get a matched set

I would replace the springs

Exactly-- replace all the valves (Manley one piece) If you look up the cam they tell you the recommended springs and lifters to use they do make a kit I would also go for the ford motorsport screw in roller rockers..

http://usaperform.com/ford-351c-351m-flat-tappet-lifter-230%C2%B0230%C2%B0-lift-p-3118.html

 

[Mystic Fish]

I would replace all the valves

I would get a matched cam / lifter / spring set

Since you already have the cam, you might not be able to get a matched set

I would replace the springs

Exactly-- replace all the valves (Manley one piece) If you look up the cam they tell you the recommended springs and lifters to use they do make a kit I would also go for the ford motorsport screw in roller rockers..

http://usaperform.com/ford-351c-351m-flat-tappet-lifter-230%C2%B0230%C2%B0-lift-p-3118.html

The website above mentions "We recommend ML657 Pro-Duty lifters with hard face bottom & .012 lube oil hole for additional oil supply to vastly extend lifter & cam life."

What is the .012 lube oil hole referencing? Is it something that needs to be done to the block?

 

[jbojo]

I believe that there is an oiling hole on the base of the lifter to provide lubrication to the cam surface.

Nothing needs to be done with the block.

 

[Carolina_Mountain_Mustangs]

It is a little more work but usually worth the effort. If you do your engine break in with a set of stock springs the cam and lifters have a better chance of seating without excessive wear. If you assembly with your new springs made for the cam and get the spring pressures balanced with shims. You can wire them together and number and put them back on after the break in. You can change springs with heads on the engine, for sure not as easy as pulling the heads but saves the gasket costs.

Remember no racing or performance cam is going to give the service of a stock set up. All that spring pressure and extra lift adds lots of stress to the components and failure will happen much sooner with racing and performance parts. They are made for running trips down the strip or a few laps on the track not thousands of miles idling around town and on the road.

I think Dave's valve got broke when it was stuck open and piston hit it. Lots of crud in there. Could you see the eyebrow mark in the piston?

David

 

[Mystic Fish]

It is a little more work but usually worth the effort. If you do your engine break in with a set of stock springs the cam and lifters have a better chance of seating without excessive wear. If you assembly with your new springs made for the cam and get the spring pressures balanced with shims. You can wire them together and number and put them back on after the break in. You can change springs with heads on the engine, for sure not as easy as pulling the heads but saves the gasket costs.

Remember no racing or performance cam is going to give the service of a stock set up. All that spring pressure and extra lift adds lots of stress to the components and failure will happen much sooner with racing and performance parts. They are made for running trips down the strip or a few laps on the track not thousands of miles idling around town and on the road.

I think Dave's valve got broke when it was stuck open and piston hit it. Lots of crud in there. Could you see the eyebrow mark in the piston?

David

I don't think there is an eyebrow mark visible. It looked to me like the valve failed, but the pushrod was bent as well so that suggests to me that there was piston contact. We should probably look at the piston closer when parts are picked up from the machine shop just to see...

My main question really is related to stock spring pressure both seated and open. If the stock spring pressures are vastly different than the slightly hotter cam is requiring, I would like to understand why. I have built several big block Mopars in the distant (1970's and 1980's) past with very similar cam specs and never changed the stock springs. And they were only street cars. Like Dave's motor, the only change was the hotter camshaft. I realize that a 351C 4V is a different animal and for that reason I would like to know if I am thinking about it wrong.

I have discussed it with Dave regarding cam break in with the stock springs, but I really would like to compare the stock spring pressures with the springs suggested by the cam card. I cant seem to find any information on what the stock spring pressures should be.

I believe that there is an oiling hole on the base of the lifter to provide lubrication to the cam surface.

Nothing needs to be done with the block.

Thanks John, I thought this may be the case. We need to look at the lifters that came with the cam to see if it is like this one.

Jeff-

 

[MeZapU]

I have my own spring tester. So far I have not found a single factory valve spring to have over 80psi at a 1.80" installed height. If they are 40+ years old they have no place in a engine running todays camshaft profiles. The valves are not worth the cost of them breaking either. You can get a pretty decent of Ferrea 5000 series valves off of eBay for reasonable money. The other big deal with new valves is ditching the stock multi grooved keepers which were a secondary point of failure in the original heads.

http://www.ebay.com/itm/Ferrea-Stainless-Valves-Ford-Boss-302-351C-429-460-Intake-Exhaust-2-190-1-710-/252283312900?hash=item3abd41db04:g:H6UAAOxy9LxSHMJm&vxp=mtr

The Manley valves are very good but they seem overpriced in my opinion for something that they have been producing for 40+ years.

If your heads have never been rebuilt you don't really need to have hardened seats installed. Especially considering the limited mileage it may see being a classic.

EDM lifters are not as important as the base oil used. I have an example set of chewed up EDM lifters with <50 miles on them because of attempting to use Rotella T as a break-in oil.

Upgrading the aged valvetrain components in the 351c is an endeavor but necessary to restore it to a modern performance level.

 

[Qcode351mach]

I have my own spring tester. So far I have not found a single factory valve spring to have over 80psi at a 1.80" installed height. If they are 40+ years old they have no place in a engine running todays camshaft profiles. The valves are not worth the cost of them breaking either. You can get a pretty decent of Ferrea 5000 series valves off of eBay for reasonable money. The other big deal with new valves is ditching the stock multi grooved keepers which were a secondary point of failure in the original heads.

http://www.ebay.com/itm/Ferrea-Stainless-Valves-Ford-Boss-302-351C-429-460-Intake-Exhaust-2-190-1-710-/252283312900?hash=item3abd41db04:g:H6UAAOxy9LxSHMJm&vxp=mtr

The Manley valves are very good but they seem overpriced in my opinion for something that they have been producing for 40+ years.

If your heads have never been rebuilt you don't really need to have hardened seats installed. Especially considering the limited mileage it may see being a classic.

EDM lifters are not as important as the base oil used. I have an example set of chewed up EDM lifters with <50 miles on them because of attempting to use Rotella T as a break-in oil.

Upgrading the aged valvetrain components in the 351c is an endeavor but necessary to restore it to a modern performance level.

:goodpost:

There ya go all the information you need..::thumb::

 

[barnett468]

you need valve springs

that cam is horrible, send it back for a refund

what is his gear ratio?

crane ant pump lifters or crower cam oiler lifters are fine.

the ML657 lifters are solid not hydraulic and they look like crap on the bottom.

 

[Mystic Fish]

you need valve springs

that cam is horrible, send it back for a refund

what is his gear ratio?

crane ant pump lifters or crower cam oiler lifters are fine.

the ML657 lifters are solid not hydraulic and they look like crap on the bottom.

What makes the cam horrible, is it the manufacturer or the grind?

 

[Mystic Fish]

I would replace all the valves

I would get a matched cam / lifter / spring set

Since you already have the cam, you might not be able to get a matched set

I would replace the springs

Exactly-- replace all the valves (Manley one piece) If you look up the cam they tell you the recommended springs and lifters to use they do make a kit I would also go for the ford motorsport screw in roller rockers..

http://usaperform.com/ford-351c-351m-flat-tappet-lifter-230%C2%B0230%C2%B0-lift-p-3118.html

I looked up this camshaft in the Erson catalog and it is indeed a mechanical lift cam. We will be using a hydraulic cam and lifters, so this lifter recommended with the .012 oil hole will not be necessary.

Thanks for the input though.

 

[barnett468]

you need valve springs

that cam is horrible, send it back for a refund

what is his gear ratio?

crane ant pump lifters or crower cam oiler lifters are fine.

the ML657 lifters are solid not hydraulic and they look like crap on the bottom.

What makes the cam horrible, is it the manufacturer or the grind?

thats an antiquated grind . the ridiculous amount of 310 adv duration is laughable on a street car and is going to spit lots of compression right back out the valves.

it should also have a dual pattern to compensate for the poor exhaust to intake flow.

you also need to know his gear ratio and tire size and converter stall if he has an auto etc.

 

[Mystic Fish]

you need valve springs

that cam is horrible, send it back for a refund

what is his gear ratio?

crane ant pump lifters or crower cam oiler lifters are fine.

the ML657 lifters are solid not hydraulic and they look like crap on the bottom.

What makes the cam horrible, is it the manufacturer or the grind?

thats an antiquated grind . the ridiculous amount of 310 adv duration is laughable on a street car and is going to spit lots of compression right back out the valves.

it should also have a dual pattern to compensate for the poor exhaust to intake flow.

you also need to know his gear ratio and tire size and converter stall if he has an auto etc.

The amount of compression retained has more to do with the cam LSA and intake centerline when the duration @.050 is taken into account.

If you have a suggestion on a dual pattern spec that is more suitable for a 351C 4V with a 4 speed I would love to hear it. I believe the rear end ratio is 3.23 but I could be wrong.

I only gave the cam specs for knowledgeable members on the forum to give advice on my original questions regarding spring pressure. This cam was not simply picked because of a set of numbers in a catalog. The cam was recommended after consulting with the machinist and the manufacturer based on the application.

The only down side to a Cleveland head is the amount of work they need for performance. With your build you will not have to go to screw in studs, but I feel single groove lock valves, and hardened exhaust seats are always worth the investment. I would never use stock springs on any new cam unless you are SURE of their quality and stats. Make sure to switch to steel fulcrums for your rockers if you stick with the stamped steel units. Good Luck, and have fun!!

Can you recommend a source for the steel fulcrums?

 

[barnett468]

If you have a suggestion on a dual pattern spec that is more suitable for a 351C 4V with a 4 speed I would love to hear it. I believe the rear end ratio is 3.23 but I could be wrong.
I only gave the cam specs for knowledgeable members on the forum to give advice on my original questions regarding spring pressure. This cam was not simply picked because of a set of numbers in a catalog. The cam was recommended after consulting with the machinist and the manufacturer based on the application.

sorry but unless that engine has around 12:1 compression, they have no idea what they are doing and of course the cam mfg isn't going to tell you that their cam is crap and you should buy another brand . all mfgs will tell you to buy what they have to sell.

also is the same mfg that suggested a slid when you wanted a hydraulic or something?

need more info on the engine and what cam he currently has and what he does and does not like about, it but off the top of my head, a comp xe268h is a good choice.

 

[MeZapU]

I suggest you contact the custom camshaft company who made the one for my engine. It may be more roudy than you want for your engine, but honestly it runs better than the specs would lead you to believe. They will build you a camshaft to support whatever drivability and power specs you would want.

 

[Mystic Fish]

I suggest you contact the custom camshaft company who made the one for my engine. It may be more roudy than you want for your engine, but honestly it runs better than the specs would lead you to believe. They will build you a camshaft to support whatever drivability and power specs you would want.

Thanks for the input Mike, but it does seem a bit much for a mostly stock 351C 4V motor. I wasn't really looking for a different cam, just looking for stock valve spring pressures. The plan is to break in the new cam with the stock springs and upgrade the springs to the matched set recommended for the cam from the manufacturer after break in is complete. I don't think 2000 RPM will be a problem for stock springs based on info from earlier in this post. I am going to try to check seat pressure on all of the stock valves and make sure they are not damaged.

Jeff

 

[MeZapU]

When you are reassembling the engine ensure your lifters install without binding in their bores. I recommend a Cloyes timing chain as they always seem to fit perfectly.

I used some Pennzoil high mileage 10w30 and a bottle of Prolong oil additive for my engine break-in. I based it on the oils wear ratings, availability and price/value. Even with my cam in those pics and the big vale springs, it broke in perfectly.