351 w roller mods

[broncobeater]

Hello to all, thinking of changing my 351 w over to roller cam. Can someone help me with what exactly is different that needs to be addressed. Specifically
having to do with the timing set, push rods, and lifters/retainers needed. I currently have iron heads but they have been machined with 1.94" int 1.60" valves and 7/16's studs with adjustable 1.6 ratio rockers. Appreciate any help. Darrell

 

[Broncobowsher]

Do you have a roller block?

 

[latrucker]

Just converted mine over to roller cam with a non-roller block. All you need is a set of link bar roller lifters. Then you'll need to measure for the correct pushrod length because 9 out of 10 times your old ones from the flat tappet won't be the correct length with the new lifters. Purchase the roller cam of your choice and your ready to run. If you have a roller block already then use regular roller lifters with the bolt down spiders instead of link bar lifters.

 

[broncobeater]

Do you have a roller block?

No, Early 70's block w/flat tappet hydraulic cam.

 

[broncobeater]

Just converted mine over to roller cam with a non-roller block. All you need is a set of link bar roller lifters. Then you'll need to measure for the correct pushrod length because 9 out of 10 times your old ones from the flat tappet won't be the correct length with the new lifters. Purchase the roller cam of your choice and your ready to run. If you have a roller block already then use regular roller lifters with the bolt down spiders instead of link bar lifters.

What about timing chain and gears? Also what distributor gear do I run with that?

 

[Broncobowsher]

Chain and gears do not change for roller.
Check with the cam supplier, but generally (not always as I learned the hard way) you need to change the gear or distributor for a steel gear. I once got an Isky roller cam but it needed the cast gear and not the steel gear that I used. Details in the fine print.

 

[tirewater]

Also determine if you need a small base circle camshaft. As mentioned above, details.

 

[Broncobowsher]

Find the cam grind you want to run. Most any of the cam manufacturers will have retrofit (link bar) lifters to make it work. Call the manufacturer (not the retailer, you want the guys that make the parts not the ones selling them) and talk with the tech department. That will fill in a lot of details.

The small base circle cams can generally be avoided. They come in handy when trying to run OEM style roller lifters (dog bones not link bars) in a non-roller block. But the grinds are limited.

 

[broncobeater]

Thank you much for the advice. Gonna go with a little more cam than I was previously running, but nothing too big. rpm range of about 1,600 to 5,800. I drive it like I stole it anyway, so should be fun. Thanks again.
PS: Whats the best way to measure push rod length? Running roller rockers and 5/16" hardened push rods.

 

[Broncobowsher]

Pushrod gauge tool. I have one that is marked the range. Each turn is 0.100". So you play with the pushrod and the rocker arm adjustments so the rocker arm spends as much as possible centered over the center of the valve tip. Pull out the pushrod, count the turns and add that to the base dimension, order up pushrods.

I used Comp Cams Hi-tech Checking Pushrod.

 

[Timmy390]

PS: Whats the best way to measure push rod length? Running roller rockers and 5/16" hardened push rods.

With one of these however this one is a ball on ball and may not work for you.

http://www.alexsparts.com/7-400-8-400-pushrod-length-checker-351w-5-16-tube-5-16-ball-ball-ends/

Tim

 

[latrucker]

Here is a link to one of the best rocker geometry/ pushrod length techniques that I have used.
https://youtu.be/o5is9BsH5OU
Very simple technique from a well respected engine builder. This is the length checker I used, works good and it's cheap https://m.summitracing.com/parts/tfs-9001

 

[broncobeater]

Thankyou gentlemen. Ordered Comp cam, comp double roller timing set, roller rockers, a new MSD distributor and new MSD plug wires and gaskets.

 

[broncobeater]

Big question.... can you swap cams with engine installed in these bronco's??

 

[needabronco]

You can remove the grill or cut a hole in it. Frankly its easier to pull the engine.