Head porting question.
Two options. One is to get a transformer, best
a Variac (variable autotransformer, check the
local electronics surplus places; I have at least
three from yard sales). The other is to get a
dimmer switch, if you can find one that's also
rated for ceiling fan speed control that would be
good but I have run the grinder off a "plain old"
with no trouble. Put it in a metal 2-gang work
box with a pair of sockets and a switch + socket
cover, all out of the electrical supplies junk tote.
I think the dimmer one seems to "cog" more at
low speed setting than the transformer, which
seems smoother. But either ought to work.
a Variac (variable autotransformer, check the
local electronics surplus places; I have at least
three from yard sales). The other is to get a
dimmer switch, if you can find one that's also
rated for ceiling fan speed control that would be
good but I have run the grinder off a "plain old"
with no trouble. Put it in a metal 2-gang work
box with a pair of sockets and a switch + socket
cover, all out of the electrical supplies junk tote.
I think the dimmer one seems to "cog" more at
low speed setting than the transformer, which
seems smoother. But either ought to work.
Question about the intake port in the pic up top -
what did you (whoever) use for a template, and
how far is too far? I am envisioning going with a
Professional Products 85mm TB/intake some time
later and would like to pre-port-match to that so
as not to take the heads off once done. I guess
maybe they'd sell me a gasket to use. Wondering
if anyone knows about the stock O-ring vs PP
paper gaskets and the range of manifold port sizes
and shapes out there. How much slop to allow for
manifold variation etc.?
what did you (whoever) use for a template, and
how far is too far? I am envisioning going with a
Professional Products 85mm TB/intake some time
later and would like to pre-port-match to that so
as not to take the heads off once done. I guess
maybe they'd sell me a gasket to use. Wondering
if anyone knows about the stock O-ring vs PP
paper gaskets and the range of manifold port sizes
and shapes out there. How much slop to allow for
manifold variation etc.?
I used an intake manifold gasket. I also have a spare set of intake
mani's that I'll be working on and I'll use the same gasket so they
will be closely matched with the heads.
I think it is better to be more conservative of the port size on the
intake mani than on the intake port of the head. I think if the port
on the intake mani is too big, the gasket will disrupt the flow. And
if the port on the head is slightly larger than the gasket, you might
lose some velocity but it wouldn't cause much if any flow disruption.
Maybe that makes sense. Someone please correct me if I'm wrong.
Oh yeah, I was able to reach the rest of the short side by flipping
a cartridge roll. thanks
mani's that I'll be working on and I'll use the same gasket so they
will be closely matched with the heads.
I think it is better to be more conservative of the port size on the
intake mani than on the intake port of the head. I think if the port
on the intake mani is too big, the gasket will disrupt the flow. And
if the port on the head is slightly larger than the gasket, you might
lose some velocity but it wouldn't cause much if any flow disruption.
Maybe that makes sense. Someone please correct me if I'm wrong.
Oh yeah, I was able to reach the rest of the short side by flipping
a cartridge roll. thanks
On The Tree
Joined: May 2004
Posts: 122
Likes: 0
Daniel I like to use 60 grit for a final finish on the intake side I used Standard abrasives roll but the 3m rolls have been known to do even better work.. Try to spin the grinder at one smooth rpm with a smooth back and forth motion with light pressure once the end of the rool gets rounded then start to finish...Here are some pics of some 60 s/a rolled cobra cylinder heads...
Two differn't 4.6 4v heads both expected to make over 1000 rwhp...
Xrated billet e85 project..
TT 302 4v
Two differn't 4.6 4v heads both expected to make over 1000 rwhp...
Xrated billet e85 project..
TT 302 4v
Daniel, looks good. cool your doing it yourself. After TONS of hrs you can the feel alot better, and your carbide finish will be great.
For the SSR I use a 3/8th round file, often. Its easy to control in weird positions.
heres some pics and info that might help you, one set of L67 3800 heads I did. Very budget DIY setup, lots of stock parts. Gen3 M90 no spray, went 11.4 in my GTP at 3250#s
http://www.clubgp.com/newforum/fb.as...anguage=single
For the SSR I use a 3/8th round file, often. Its easy to control in weird positions.
heres some pics and info that might help you, one set of L67 3800 heads I did. Very budget DIY setup, lots of stock parts. Gen3 M90 no spray, went 11.4 in my GTP at 3250#s
http://www.clubgp.com/newforum/fb.as...anguage=single
