351W block - retro fit for roller cam

[COACH MIKE]

I am in the process of putting together a 351W stroker (408). I have been told If I use a roller cam and rockers I will need a roller block (94-95 351W roller engine) or have a non roller block retro fitted. What is retro fitting? How difficult is it to have done? How much cost? I have a friend who will sell me a 74 351W block. Is it worth the effort and expense to retro- fit this block as apposed to finding and buying a roller block? Thanks for the help, in advance.

[mstngjoe]

The '94 and later 351W were roller blocks.

To retrofit a non-roller 351W you have a couple of choices. One is a kit that is like the regular 302 roller setup. It requires some holes drilled in the lifter valley to mount brackets/spiders to locate the roller lifters in the bores. This setup requires a small base circle cam.

The other way is a set of link-bar type roller lifters. This is a drop-in retrofit and allows you to use any OTS 5.0 cam.

A roller cam will also require a change in your distributor gear along with the correct length pushrods. You may also have to upgrade your springs depending on the heads you will be using.

I researched going to a roller cam for my 331. I determined that for my application and desired performance level, it wasn't worth the additional cost.

If I were to do it though, I'd use the Crane link-bar retrofit lifters instead of the 5.0 setup.

Hope that all helps.

[PSB]

I went the spider/small base circle cam route on my 408W. The small base circle cam was much cheaper than the lock-bar lifters. Adding the spider is pretty easy - just requires two holes to be drilled and tapped in the lifter valley in order to bolt down the spider.

Before:


After:



Pete

[Mr.Fixit]

PSB showed the way I recommend. Plus, with some stroker combos, you need a small base circl cam or the con-rods can kiss it.

[CowtownCobra]

I did the same as PSB. Used all Comp Cams parts. Very satisfied.

[mstngjoe]

Boy, you guys got me outgunned on this one.

This link has some info regarding small base circle cams and the link bar type retrofit lifters.

If you read down a ways, you'll note postings by Ed Curtis and Buddy Rawls. They are both highly respected cam specialists who spec custom cams (among other engine related things). They both have more knowledge and experience than I do, so that's why I pay close attention when they post.

I've worked with Buddy on two engines and was more than satisfied with his cam and recommendations.

http://www.corral.net/forums/showthr...06#post2259306

I'm not saying there are a lot of the 5.0 style retrofits running around with problems. Just that I had a doubt in my mind. That's why I would have used the link bar lifters had I decided to go roller. (They're about $400 for a set).

I'm just offering up some other views.

[Dwight]

HEY COACH, DID YOU NOTICE THAT BUDDY RAWLS LIVES IN MADISON?

[mstngjoe]

I didn't notice you guys were in Buddy's neighborhood.

Here's his website:

http://www.wighat.com/fcr3/camtruth.htm

Took me a few readings to grasp it. Still not sure I get it all.

[sllib]

If the rods will hit the cam on a big stroker, what good will link bar lifters do? I think Mr. Fixit answered Coach's question short and sweet.
Bill Stradtner

[Jack21]

Did it the PSB & Mr. Fixit way also using CompCams kit & components. Works extremely well, no reliability or maintenance issues, and revs just fine up to 6200 RPM shift point.

Machine shop milled a small flat in the center of the lifter valley for the spider, tapped threads for the spider bolts, and locktite'd the spider bolts in place.

A little clearancing was required at the top of the lifter bosses to accomodate the locking bars.

Installed the valvesprings that came with the cam on the heads (but I do that with every cam).

Pushrods had to be measured for correct length, then special ordered.

Used CompCams ProMagnum steel roller rocker arms for longevety on street motor. Comp recommends factory refurbishing whenever the heads are off for a valve grind.

Used FMS steel distributor gear on distributor for roller cam.

Torque is awsome, motor idles with a slight lope at 850 RPM, and pulls 15" - 16" vacuum at idle. Had to jet down beacuse vacuum signal to carb is so strong.

[CowtownCobra]

Jack21

I used a 284HR cam along with the parts you mentioned, and it just pulls like a SOB.

Which cam did you go with?

[mstngjoe]

Originally posted by sllib


If the rods will hit the cam on a big stroker, what good will link bar lifters do? I think Mr. Fixit answered Coach's question short and sweet.
Bill Stradtner

If you are satisfied with short and sweet, so be it.

I was presenting an alternative to drilling & tapping the block and using a small base circle cam.

The spider setup in an early non-roller block requires a small base circle cam because the lifter bores in non-roller blocks are shorter than in roller blocks. You need the small base circle regardless of clearance issues. And the 408 normally doesn't have the rod/cam clearance problem. You mostly see that in the 427.

The rod/cam clearance issue can also be solved by using a profiled stock or aftermarket rod without resorting to the small base circle cam.

The link-bar lifters allow the use of the stock base circle cams. Of which there are tons more choices in specs than the small base circle. And if you decide the cam you choose isn't right, it's easier to unload a standard cam than a small base circle one.

When I do a project I like to have all the info available before I make a decision.

But that's just me.

[Dwight]

HEY, MSTNGJOE

COACH AND I LIVE 50 MILES WEST OF MADISON, ALA. ABOUT ONE HOUR DRIVE.


THANKS FOR THE LINK!!!!!!!!

[mstngjoe]

Originally posted by Dwight


HEY, MSTNGJOE

COACH AND I LIVE 50 MILES WEST OF MADISON, ALA. ABOUT ONE HOUR DRIVE.


THANKS FOR THE LINK!!!!!!!!

No problem.

I wish I was that close to him. I've talked to him on the phone twice and exchanged literally dozens and dozens of emails with him over the past couple of years. He's a great guy.

I think it would be well worth your time to touch base with him and see what he might recommend relative to your build. He charges about $30 for custom specs. He can handle the grind thru Comp and will check it for correctness once it's done.

Good luck with your project and let me know how it goes.

[Dwight]

MIKE AND TALKED A LITTLE ABOUT A COBRA RIDE TO SEE BUDDY. WE'LL CALL HIM AND SEE IF WE CAN VISIT.

[Jack21]

I'll have to look up the CompCams part number, but the spec's were single pattern 224I/224E & .533"/.533". Personally, I Like 8 - 12 deg more exhaust duration than intake. Cranes generally do this, but Comp's generally don't.

Can't complain withthe Comp single pattern; it works.

[CowtownCobra]

Thats the same one I have