Pushrod or Overhead?

[86FireBird]

Now of course all the f-body drivers here have pushrod V8s but im wondering what most people think is better and would prefer given the choice.

I myself prefer the traditional pushrod setup but there are lot of people who say they are outdated and that SOHC and DOHC engines are way better.(even thought i notice the opposite in performance wise)

Any opinions?

[raroZ28]

OHC is much easier to work on. Pull the valve cover and you can swap everything out that you need.

I think I'd rather have the OHC, but Chevy has proven that you can use pushrods and still have tons of power, reliability, emissions, mileage, etc...

[ConElite]

If GM can make a 500hp N/A engine with one Cam, and takes Ford 4 cams+S/C and not make anywhere near as much Power, then Theres something there.

Raro Is right, That it does make it easier to work on if its OHC but as for Power, The ol push-rod is king. ha ha ha No F-body or Vette Im sure ever came with OHC. So.

But If someone wants to buy me a Ferrari with 4 cams and Only 400 hp, "ILL TAKE IT!"

[raroZ28]

If GM can make a 500hp N/A engine with one Cam, and takes Ford 4 cams+S/C and not make anywhere near as much Power, then Theres something there.

Raro Is right, That it does make it easier to work on if its OHC but as for Power, The ol push-rod is king. ha ha ha No F-body or Vette Im sure ever came with OHC. So.

But If someone wants to buy me a Ferrari with 4 cams and Only 400 hp, "ILL TAKE IT!"

http://en.wikipedia.org/wiki/LT5

DOHC. Most high HP motors use DOHC. Chevy is the only exception.

[Injuneer]

There have been rumours for several years now about a future version of the LSx engine that will use dual cams...... MOUNTED IN THE BLOCK.... one above the other. This will allow variable intake/exhaust valve timing with the traditional cam-in-block/pushrod design.

Not all DOHC designs are "easier to work on". I had a 1975 Alfa Romeo Alfetta GT 4-cyl, with chain driven dual overhead cams. The valve adjustment was EXTREMELY painful, with the need to take measurements of the existing lash, remove the cams, and replace the caps on each valve with a cap of the correct thickness, reassemble the cams, then recheck the lash.... repeat procedure until you got it right. A monument to Italian engineering . It was also necessary to remove the cams to do many types of engine maintenance, including the replacement of the water pump gasket. To do that you also had to pull the head, since a couple of the head bolts went into the water pump housing.

[Christopherrr]

F-body or Vette Im sure ever came with OHC.

The ZR1's came with the LT5 DOHC Lotus Engine...

[Christopherrr]

Over all, I think OHC engines are rather easier to work on, but for weight and compactness, OHV are the way to go...

5 years ago, people said OHV are of the past...now, just point to an LS1-2-3-6-7 and smile.

I'm down for whatever the general makes...I like to know I can work on my own cars, OHVs it is!

[ConElite]

The ZR1's came with the LT5 DOHC Lotus Engine...

Ha ha ha. I was Close.

[86FireBird]

If GM can make a 500hp N/A engine with one Cam, and takes Ford 4 cams+S/C and not make anywhere near as much Power, then Theres something there.

Raro Is right, That it does make it easier to work on if its OHC but as for Power, The ol push-rod is king. ha ha ha No F-body or Vette Im sure ever came with OHC. So.

But If someone wants to buy me a Ferrari with 4 cams and Only 400 hp, "ILL TAKE IT!"

I was gonna bring up that point on how it takes ford so much more to make that power. I think the LSX series is the ultimate exception to the saying that pushrods are outdated. I mean even the northstar 32 valves arent making that much power. And the ford 32 valves are even more under powered.

The only down fall i can see about the pushrod engines is that the extra mass of the pushrod puts more stress on the valve springs and i think for that reason the redlines were considerably lower then the over heads. But now im seeing the GTO's and corvettes with these 6500 plus RPM redlines so i think theyve manage to overcome that.

I doubt they will ever get near rotary engine capacity though (9000 and up)

[MunsonGTA]

OHC and DOHC are great motors if you put forced induction to them, if not... rev it to the moon and you still won't get much power. my dad has an OHC motor in his 2000 explorer sport... what a great piece of shit. the timing chain broke, and since it's an interference motor... everything else also broke. i'm talking pistons, valves, heads.... everything.

[ConElite]

OHC and DOHC are great motors if you put forced induction to them, if not... rev it to the moon and you still won't get much power. my dad has an OHC motor in his 2000 explorer sport... what a great piece of shit. the timing chain broke, and since it's an interference motor... everything else also broke. i'm talking pistons, valves, heads.... everything.

Well here is the problem. Let me circle it for you.






I had to

[86FireBird]

OHC and DOHC are great motors if you put forced induction to them, if not... rev it to the moon and you still won't get much power. my dad has an OHC motor in his 2000 explorer sport... what a great piece of shit. the timing chain broke, and since it's an interference motor... everything else also broke. i'm talking pistons, valves, heads.... everything.

ive heard that before with ford over head motors with the timing chain breaking...the pistons start striking the valves and all hell breaks loose...

luckily ConElite circled the problem

[MunsonGTA]

ive heard that before with ford over head motors with the timing chain breaking...the pistons start striking the valves and all hell breaks loose...

luckily ConElite circled the problem

that's exactly what happened. let me point this out though, my grandfather worked at ford for 38 years here in ohio, needless to say we get a GREAT discount on all ford vehicles...

i myself drive a chevy cavalier and an 87 pontiac GTA.

[86FireBird]

I mean i love all american cars for the most part but i really can get behind ford anymore (but they do have nice trucks but thats about it) Im mostly a GM and Mopar guy (mostly GM by far). As far as the classic muscle cars i love em all

[Jeff 97SS]

I believe over head cams first debuted in Alfa Romeo's 1927 grand prix car, and they've been used in various applications ever since. Therefore OHC fans calling pushrods old tech is kind of like the pot calling the kettle black.