[Fot] Roller Rockers

[Ted Schumacher]

Allen Washatko wrote:
> FoT,
>
> I need some input regarding the use of roller rockers on a race 
> prepared TR6. If you are running a cam with .500 lift and 300 degrees 
> duration, does the use of a higher ration roller rocker (1.65) really 
> add that much more power? This is assuming that the head is well ported 
> and you are running the largest intake/exhaust valves that fit in the 
> head. I was just made aware of some engine testing recently that 
> indicated that there was only a 2 h.p. gain by using roller rockers 
> with the above modifications. It also indicated that the increased 
> ratio caused more wear on the cam, tappets, etc. The logic as presented 
> seems to be  that you can only draw so much flow through the head 
> before you get diminishing returns. Any thoughts on this?
>
> Allen
>
>
> Allen & Jody Washatko
> 1971 TR6  - Number 6
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Allen, Bill B.is correct.  The big advantage to roller rockers is 
reduction of valve stem/valve guide wear.  High ratio rockers for your 
car - 1.65 - greatly increase valve train strain and wear. Even the 
fastest TR6 in current SCCA Production form is only runing 1.55.  We 
sell a goodly number of roller rockers and do not recomend or sell the 
1.65.for your application. Jack Drew's comment about filming roller 
rocker tips certainly has merit. But, at what enginespeed.  The engines 
in our cars, othe than the small Spit engines, don't see 8500 - 9000 
rpm.  Ted

-- 
Ted Schumacher
tedtsimx at bright.net
http://www.tsimportedautomotive.com
108 S. Jefferson St.
Pandora, Ohio, USA 45877
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