combustion chamber question
Didn't do any “hogging out“ or anything major anyway, so chill out.
Not sure if you've ever done any port work yourself, but a dremel sucks for this job and will not reach in far enough.
hey Mart00SS, looks great, and I see you were sure to leave the spiral ramp there by the valve guide that I was taking about, and even exaggerate the other side. Care to share any more photos?
So do you just put sealer paste on your rocker bolts since you went through to the threads? I'm not planning on taking mine down nearly that far, just curious.
So do you just put sealer paste on your rocker bolts since you went through to the threads? I'm not planning on taking mine down nearly that far, just curious.
TECH Resident
Joined: Sep 2009
Posts: 859
Likes: 2
From: Frozen Tundra, WI
You may not have liked the way he came across but he was just trying to point out some serious flaws that unknowledgeable people make. Just removing a bunch of material does not make for a great port. I am guessing the exhaust ports in the pics have been...ummm...trashed. You don't see CNC ports like that. Sorry to be the bearer of bad news.
To the previous poster that pointed out that velocity is our friend ,,,,,u r correct but really first thing needed is what the owner has intended for said engine , then devise the plan ,,,,,,for instance to retain plenty of low and mid tq and no real need for power at 5500-7000 You'd want to leave most of the ramp and not remove very much material and semi-rough ,,,,,,,for 3000-7000 You can remove quite a bit of material and polish or at least sand intake runners fairly smooth . I've talked with 3 or 4 reputable engine builders that r saying that they (engine builders) r finding that in fact a semi-rough intake runner surface even in high rpm applications is beneficial ,,,,,as opposed to previous thinking . Lets say You want maximum material removal for max power at high rpm's so You port intakes to 220cc and smooth and compare to same head with a little more removed say 225 or so and rough the little vortex's would resist flow thus creating more velocity =power,,,,,makes sense do u think ?
Teching In
Joined: May 2011
Posts: 9
Likes: 0
From: Chandler, AZ
yeah, thanks for the warning. These heads I have were essentially free, so gonna try them out before going to cnc ported heads on this particular shortblock like in my other truck....
Didn't do any “hogging out“ or anything major anyway, so chill out.
Not sure if you've ever done any port work yourself, but a dremel sucks for this job and will not reach in far enough.
Didn't do any “hogging out“ or anything major anyway, so chill out.
Not sure if you've ever done any port work yourself, but a dremel sucks for this job and will not reach in far enough.
I finished mine with 80 grit on intake (obviously left some rougher spots I couldn't get to with the shank I had, but they are still a little smoother than factory cast):
I did 120 grit on the exhaust (did not do any carbide cutting, just cleaned them up with 2 stages of sanding rolls best I could). They felt extremely smooth to touch:
I did 120 grit on the exhaust (did not do any carbide cutting, just cleaned them up with 2 stages of sanding rolls best I could). They felt extremely smooth to touch:
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Verdad Gallardo thunderstruck, looks like you really took down that intake ramp!
I ended up cleaning the casting lines a hair more, and blending the exhaust valve guide more too. Left a bit of the upper exhaust ramp thing too, wasn't too sure what to do with that.
I guess I'll try to post a few photos of mine when I get finished, since everyone else is too!
A friend who went to SAM did the carbide work.
I would have done the same though, from the reading I've done on porting heads on here for the last 2 years have been fairly unanimous that the ramp needs to be removed if you expect results. The only defense I heard for keeping it was velocity for low end.
I went from a smaller cam and stock ls1 heads to these and a 230/238 cam and gained a very noticeable amount of low end, so I'm going to say I have no regrets about how they were ported as of now. Track results will make me more confident in the work we did.
I would have done the same though, from the reading I've done on porting heads on here for the last 2 years have been fairly unanimous that the ramp needs to be removed if you expect results. The only defense I heard for keeping it was velocity for low end.
I went from a smaller cam and stock ls1 heads to these and a 230/238 cam and gained a very noticeable amount of low end, so I'm going to say I have no regrets about how they were ported as of now. Track results will make me more confident in the work we did.
i think i might get a intake and exhaust flow benched to better match a cam to my set up. anybody else have any pics of there heads? be great if somebody had some flow numbers to go along with some pictures. keep em coming
Intake Runner and Chamber Finish I am not a professional, but I am with most of the people on this thread. I have always been taught that the intake runner needs to have a certain amount on surface roughness to promote proper port turbulence and fuel mixer. A polish finish leads to loss of fuel charge suspension and increased boundry layer.
The chamber can be polished pretty smooth as it promotes improved filling and heat retention. It also helps to reduce carbon build up and gets rid of hot spots that are responsible for detonation.
The exhaust port can also be polished to promote port speed, aiding scavenging and reducing carbon build up.
IMO, Mart00 I think your ports look darn close for a doing them yourself, better then I have achieved. Nice work!
The chamber can be polished pretty smooth as it promotes improved filling and heat retention. It also helps to reduce carbon build up and gets rid of hot spots that are responsible for detonation.
The exhaust port can also be polished to promote port speed, aiding scavenging and reducing carbon build up.
IMO, Mart00 I think your ports look darn close for a doing them yourself, better then I have achieved. Nice work!
