Engine Question?

I suspect really 2 of the drawbacks had to do with chamber design and cooling the head. Dave as you know those heads have little space for water right where it is needed because of the space taken up by the valves, seats and ports. Also from my understanding of chamber design the 5 valve chamber is hardly Nirvana. The pent roof of a 4 valve is almost as close as it gets. If that is so a simple trade of thermal and combustion efficiency vs volumetric capacity is being made.

 

Dave, Brian- I do not blame a cam grinder for looking askance when asked to do a five valve intake cam. Does one of the five valves open a little earlier to induce swirl? The top, middle one, maybe? I noticed what looked like a large flat ground on the lower side of the cam, IIRC. Have to do some more looking to figure out everything that is going on. No wonder they went back to four valves, in addition to all the real estate they used, like Brian said. I wonder if the F1 engine still uses five valves?

Taz
Terry Phillips

 

F1 went to 4V years ago.

The middle valve is 20 degrees later in opening

 

Brian- Thanks.

Taz
Terry Phillips

 

the last time i took a head off a 360, it had 4 valves per cyclinder. 355 was the only 5 valver. thats what the name stood for. 3.5 liters, 5 valves per cyclinder.

 

How many 360 heads have you removed?

What did they plug that extra hole with?

Sorry you are just plain wrong.

 

Come to think of it here is a piston in a 360 motor.

Sure looks like a 5 valve piston to me.

Maybe you had the optional "Economy" version.
Image Unavailable, Please Login

 

Sorry wrong picture.

Here is a piston IN a motor.
Image Unavailable, Please Login

 

majkl- I think we all know what head is the only one with which you have been involved, and we do not discuss that in polite conversation.

Taz
Terry Phillips

 

I stand corrected, i was thinking of 348, late nite drinking will do that to the brain. you guys are right, im wrong. Taz i liked that hint, good joke. couldnt stop laughing myself off my seat

 

Mike- Too good a straight line to resist.

Taz
Terry Phillips

 

All true but it still fascinates me and I am not done with it yet.
The Motorcycle guys are finding big advancements from what was known a few years back and I am interested in a few areas of their advancements. I just like the package and it is what it is so that's what I will work with.