what happened to a plain ole roller cam pushrod engine....people getting to techical for me

dohc motors are easyer to tune and get hp out of. Most four cyl engines in drag racing are dual cam/4 valves per cylinder technology.

Sure, they just last half as long But I guess who cares when your racing...

-Ben

how would a dohc last half as long if your runing the same cam specs for the exhast and intake and runing the same spring tention and ect? you dont make much sence

More parts, more rotating mass, more chance of wearing sooner as apposed to a SOHC configuration, especially at 10,000 + revs... and I didn't mean half as long literally, but still less than a SOHC.

-Ben

more chance of wearing sooner as apposed to a sohc configuration? explain more specificly please, dont you think with 1 cam apposed to 2 cams there will be an added ammount of stress on that single cam hence less reliable at 10,000+ revs?

DOHC parts are smaller, thinner and lighter and over time "may" break sooner than a SOHC, especially when they can reach the upper limits of 10,000 RPM, not too many SOHC's going that high, especially a V8 type motor. Most DOHC's acheive there HP and torque at high RPM's, sometimes within 1,000 RPM's of redline or less, were a SOHC makes there power closer to the middle of their RPM band. Yes, the SOHC will have to run MUCH more valve spring tension to acheive the high RPM, but it isn't run as hard as a DOHC. Make sense?

where do you get dohc parts are smaller and thinner from? please explain your bull shit. You make no fucking sence at all, just because it has an extra cam doesnt mean it can go higher rpms then a single cam, shit i could build a sohc to rev higher then a dohc and vice versa, its all about how that motor is built to have its power range in what area. What the fuck are you talking about when you say : (Yes, the SOHC will have to run MUCH more valve spring tension to acheive the high RPM, but it isn't run as hard as a DOHC. Make sense? ) : if your runing the same cam specs on the intake and exhaust on a dohc and sohc why would the sohc have to have how you put it MUCH more valve spring tension? why would the dohc run harder then the sohc? you make absolutly no fucking sence at all homie

OH FUCKIN ZIP IT!!!!!!

lol! Made sense to me

-Ben

besides neon the original arguement said there were MORE part to break down now ok you may try but i don't think you can fight the fact that 2 comes after 1

bottom line is my 6 banger is going to eat your 4 banger for lunch. you ARE right that dual cams are easier to tune for hp, but a straight six singlecam vs. a big four dualcam, there is no question which has the ability to produce the most breadth in the powerband, the most torque and the most usable horsepower...the six.

jason

Ok DA, you have a Honda 1.6 liter SOHC with 2 valves per cylinder, then you have a Honda 1.6 liter DOHC that is four valves per cylinder, SOMETHING has to be smaller or bigger and it is NOT the combustion area diameter! A DOHC motor breathes/operates differently than a SOHC which makes it EASIER to acheive higher RPM's, I never said a SOHC cant go to high RPM's. Once you can actually figure out that the DOHC valves are smaller and thinner (lighter) then you may understand that it takes LESS valve spring tension to keep the valves from "floating" at high RPM's were as a SOHC with only 2 valves per cylinder (and larger/heavier valves) will need a stiffer spring to keep the valve float from happening at the same high RPM's. "Floating" is that funny noise your engine used to make when you took it 1,000 RPM past the redline. Do REALLY work at this "Top Secret" Porsche shop? I suggest that when you finally dismount your ass from your shoulders that you finally start talking with the people you work with and learn something. I know youre 19 and you have the world figured out and you dont need to learn anymore, but it never hurts to ask for a opinion.
Have you EVER had a motor apart before?

Ya know...It's funny when some new 14 year old kid comes on and says somethin stupid and we all rip him a new one...
But this 'who's dick is bigger' contest that's been goin on with the same fuckin people ever since the board has been up is gettin kinda fuckin old. Can't you guys just leave each other the fuck alone? Hell, how 'bout this...I'll drive my mom's Lumina up to cali, you can ALL race me and kick my ass, so you can all have bragging rites and then we can all start acting like fuckin ADULTS! Hell, I might have the least amount of mechanical experience on this board, but I'm the most mature person here it seems, and that's pretty fuckin scary...

hey ls4, got a question from a friend about mahle pistons & rings....clearance issues:

I have a 3.5 Euro motor that has been rotting in the
garage. It was rebuilt at some point prior to my buying
it. It was in a Euro 735 with about 90k-100k on it.
New style head cracked and car was junked.

Questions:

1). Ring clearance (flank, side, etc.)How "tight" does the
tug need to be on the feeler guage? I am coming up with .064 mm,
but the tug between feeler, ring, and ring land is light.
Allowable spec for Mahle pistons with 1.75 top rings is from .
04 to .072 mm. I cannot find specific info for this motor.

2). The top piston ring mikes out to about 1.70 mm. I would
assume that ring should a little thicker than 1.75mm. Hmmmmm.
If new rings were thicker, these pistons would start looking
a lot better.

My current 3 liter could damn well use rings, rear seal,
and the rebuilt head. If I do all of that, I am close to
rebuilding the 3.5.

Compression is damn good, around 200-205 PSI, but why is
there so much pressure in the crankcase? Bad oil control
rings?

thanks,

jason