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  #101  
Old 01-09-2018
mgty3whlr mgty3whlr is offline
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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  
Old 01-09-2018
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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  
Old 01-09-2018
rognelson77 rognelson77 is offline
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Quote:
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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  #104  
Old 03-23-2018
a21stud a21stud is offline
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At the $101,000. Duck race a boxy, stock sheetmetal Malibu runs 221 on radials in the 1/8th mile with only a dinky wing and no wheelie bars. Why did NHRA let Pro Stock get sooo far away from a “Stock” looking vehicle when they only run 214? Yes, another 660 feet can allow more air to get where you don’t want it, but they could have contained the issue without going full lump bodied. I saw the body template for a Pro Stocker the other day. It sure didn’t look like any car sold today and it was just for checking the middle length of the car. Nitro Funny Cars in 1980's wished they were that swoopy! Bernstein’s Bat Car wasn’t that swoopy.

The stretched front bumper look came around because the finish line cells are 6” off the ground where the starting lines are just 3”. To make it fair for the cars with small overhang they allowed them to be stretched to a max of 36” from the center of the front wheel. They should have either moved the finish line cell down to 3” off the ground or moved the starting line cell up to 6”. Then they would start and finish every race at the same point on all cars. Most people assume the cars are running a real quarter mile or real 1000’ when in fact, it’s closer to either 1318’ or 998’. (Track length minus 36” plus 1/2 the rollout added back in.) Plus all cars get a running start equal to the track's rollout.

Starting and finishing at the same point on the cars would allow fair racing from stock looking bodies no matter what their front overhang was. Currently the guy running a Chevy Cavalier in a Stock Class is giving up a couple feet advantage to the guy running a 1990’s Chevy Camaro with the long nose. This would fix that too. Go with the same height start and finish line cells and run a real ¼ mile or 1000’ for all classes.

Then work on smart ways to keep the cars from going airbourne while keeping them stock appearing. Splitters and logical wings instead of custom lump bodies with stickers declaring the car brand.

Yeah, I know, I'm screwing with tradition again. But tradition says we need flag starts, push starts, open face helmets, carbs, pushrods and only hand shifted manual transmissions.

Some changes have been good, some not so good. This one? The car manufacturers would like it (unless their car loses all the time).
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  #105  
Old 03-23-2018
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de31168 de31168 is offline
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