Roller or flat tappet? And which dist gear?

[Viperwolf1]

I'm pretty sure that roller cams need to be hardened because of the steep ramp rates.

 

[73azbronco]

would they have used the roller rockers because the heads are aluminum gt40?

Anything is possible, but the question begs, if they went to the expense of roller rockers, why not mod the valvetrain to roller lifters as well? Curious if they only installed roller rockers, and did not then mod to roller lifters.

 

[blubuckaroo]

I'm pretty sure that roller cams need to be hardened because of the steep ramp rates.

Hmm. Reverse of that I think.?:?

 

[Viperwolf1]

Hmm. Reverse of that I think.?:?

Hardened to withstand the loads of the roller tappets. https://www.fordracingparts.com/download/tipsPDF/EngineBuildingTipsSpecs.pdf

 

[blubuckaroo]

Hmm...
I thought lifter loads were higher on flat tappet cams. I guess we don't need the zinc additive after all.?:?

 

[Viperwolf1]

Hmm...
I thought lifter loads were higher on flat tappet cams. I guess we don't need the zinc additive after all.?:?

With the rollers the contact area is just a thin line. Flat tappets contact a bigger area.

 

[Hozr]

You need to pull the valve cover and maybe intake. I see a part in your list which is a roller rocker. I would be hard pressed to understand why they would install $500 worth of roller rockers on a flat tappet lifter/ camshaft.

What exactly does a roller rocker have to do with the cam and or distributor gear? Plenty of flat tappet engines run roller rockers without issue. If they were roller LIFTERS that's a different story bit that point is moot in this case.

 

[DJs74]

What exactly does a roller rocker have to do with the cam and or distributor gear? Plenty of flat tappet engines run roller rockers without issue. If they were roller LIFTERS that's a different story bit that point is moot in this case.

Roller rockers with flat tappets (hydraulic or solid) is a pretty normal and accepted combination. Its usually driven by costs / operating budgets. Running a flat tappet camshaft and opting for a set of roller rockers is still a good approach for reducing friction in the valve train.

Now what would be a little strange (IMO) is if someones build consisted of a roller camshaft and a set of stamped rocker arms




DJs74

 

[DJs74]

Hardened to withstand the loads of the roller tappets. https://www.fordracingparts.com/download/tipsPDF/EngineBuildingTipsSpecs.pdf

That's a great link Viperwolf!

DJs74

 

[bronconut73]

I have run roller rockers on every flat tappet engine I have built since the late 80's.
Thats only about 4 or 5 engines....
Main reason I didn't use roller cam and lifters was cost.
They can get super pricey compared to just roller rockers.
Roller rockers reduce alot of bind and friction and IMO are worth the effort and expense.
I have yet to be able to justify the cost of a roller cam/lifters..,,not that I do not want them and their broader torque curve just have never been able to afford them during my rebuilds.

 

[Labbster]

Since I am not 100 percent sure on the distributor gear, I have purchased the composite gear that is supposed to be able to be used on all materials. It was $70 extra so I think it is good insurance....

 

[73azbronco]

What exactly does a roller rocker have to do with the cam and or distributor gear? Plenty of flat tappet engines run roller rockers without issue. If they were roller LIFTERS that's a different story bit that point is moot in this case.

OK, some do it. My point was, if your into it for $450 on rockers, why not another $400 for the roller lifter kit with camshaft? That's my only point, take care.