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  #101  
Old 6 Days Ago
mgty3whlr mgty3whlr is online now
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Originally Posted by HEMI_guy View Post
The current Dodge HEMI is a pushrod engne.
Yes, you are correct but I was talking about other engine variations that are produced, G.M. is coming out with a DOHC v-8. My point was, Is it worth running an OHC combo.?
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  #102  
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Willy Willy is offline
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Originally Posted by mgty3whlr View Post
Here is my thought on using a modern day engine in P/S except the G.M. LS platform, Take Ford and Dodge for example, Their Modern engines are OHC design and sure they can build some power if massaged correctly but, What happens in between rounds if they have to replace a valve spring or 2 or three?

Now you have to deal with a timing chain or belt before you remove the camshaft to access the spring(s). Now factor in a DOHC engine, Now you have 4 cams to deal with when re-clocking the timing.
It is completely unnecessary to remove the camshafts, or disrupt the timing chains to change the valve springs on any flavor of Ford OHC engine. The procedure is identical to an OHV engine.

And even with the 32v arrangement, that does not hinder routine service of these engines by racers that make more power than a current PS engine.
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  #103  
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rognelson77 rognelson77 is offline
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Originally Posted by mgty3whlr View Post
Here is my thought on using a modern day engine in P/S except the G.M. LS platform, Take Ford and Dodge for example, Their Modern engines are OHC design and sure they can build some power if massaged correctly but, What happens in between rounds if they have to replace a valve spring or 2 or three?

Now you have to deal with a timing chain or belt before you remove the camshaft to access the spring(s). Now factor in a DOHC engine, Now you have 4 cams to deal with when re-clocking the timing.

Maybe Chris can chime in on his opinion of whether it would be practical or not to deal with the additional aggravation of doing additional work in between rounds instead of just dealing with an OHV engine. Maybe that's why NHRA doesn't want to throw these engines into the mix.

If you look at it, If you have a spring failure, It's quick. Remove 1 nut, pressurize the cylinder, remove the spring, reassemble, and check the gap. done! A lot less work.
Overhead cam engines have significantly less valve train maintenance. There would be minimal between round maintenance compared to pushrod engines. . Valve springs can be significantly lighter because in 4 valve engines, valves are lighter, rocker arms are tiny and there are no lifters and pushrods to force back with spring pressure. That is why ford coyote mustang engines rev to 7,500 from factory and Boss 302 Coyote rev to 8,200 reliably.

Lighter springs also equal less chance of valve breakage.

The big plus is variable cam timing on intake and exhaust. Expands the torque and horsepower range.

MMR now makes a Coyote 400 cubic inch block that uses stock heads. Or you could use ford V10 truck motor, I think 6.7 liter.
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