[Paul Austin]

Hi
I am in the process of trying to decide on an engine for my RV7a and Just after everyones thoughts on roller vs standard tappets do you think they are worth the extra money and has any one had any troubles with either type.

 

[Russ McCutcheon]

Hi Paul,

In my opinion and from what I?ve herd, there both good, there have been problems with the standard followers when the engine sits for extended periods often, the rust on the cam and followers tears up both. The rollers are supposed to be better with this since they roll over the corrosion. I don?t think too much of letting airplanes sit but if that?s the plan then maybe rollers would be worth the money, if you plan to fly then either will give good service. Many standard cams have survived sitting too, kind of depends on the climate I think.

 

[PCHunt]

Hi Paul,

In my opinion and from what I?ve herd, there both good, there have been problems with the standard followers when the engine sits for extended periods often, the rust on the cam and followers tears up both. The rollers are supposed to be better with this since they roll over the corrosion. I don?t think too much of letting airplanes sit but if that?s the plan then maybe rollers would be worth the money, if you plan to fly then either will give good service. Many standard cams have survived sitting too, kind of depends on the climate I think.

Russ McCutchoen
www.mccutcheonmetalfabricationaviation.com
[email protected]
We build many of your RV weldments.

Russ, how do you really spell your name? Couldn't resist, sorry!

 

[Russ McCutcheon]

eon

Thanks<VBG>

 

[Greg Dillon]

Roller tappets and roller rocker arms have a benefit of reducing friction. Although I don't have roller tappets in my H2AD, I found that Ford 351C roller rocker arms fit nicely......I hope to enjoy less wear on valve stems using the Ford parts. If you wanted to regrind your cam for more performance, roller tappets allow a more 'aggressive' cam profile without causing excessive overlap.

 

[Pat Hatch]

Paul,

I would definitely talk to Bart at Aero Sport Power as he builds them both ways. I have one of Bart's roller tappet O-360s and one difference is the case has a larger boss area for the square bore required so the tappets cannot rotate. I have heard that the roller tappets also provide better lubrication of the cam and valve stem area, but I would confirm this with Bart.

No problems so far after 3+ years operating this engine.