compression release?

[garyajaz]

any one have them?
any machining tips?

[garyajaz]

oh, also looking for a junk iron head to practice on.
any one have one?
  broken fins no valves or gudes no problem.
want to practice set up and drill and tap before i do ported axtell heads.

[garyajaz]

found a head.  going to put 10 mm releases between push rods.  top 3 fins to be machined away.

[prodrag1320]

we put them on the spark plug side

[garyajaz]

thanks for the tip.  have a head here at table.
it has the large XLR intake valve.
have seen them on top (no room with this vale)and on push rod side.
not much room on spark plug side.
do you place under plug?
wondering if it would be weaker cause of holes close with not much material?
no way a pro.  just looking at the thing.
thanks

[Hillside Motorcycle]

oh, also looking for a junk iron head to practice on.
any one have one?
  broken fins no valves or gudes no problem.
want to practice set up and drill and tap before i do ported axtell heads.

No need to practice.........just clear the fins off with a mill(BTW, a roughing cutter works best on those very hard/tough fins), and drop that release right between the pushrod tubes. Cake walk.
Scott

[garyajaz]

thanks scott.  making a jig as i type.
will set it up same angel as spark plug hole.
rotate 180 and do pilot hole.
then set up for 10 mm release.
i gonna use junk head though. 
found one.
whats anouther hour or so when i never done it before.
i have C.R. Axtell ported heads from 30 years ago..
cant mess them up....
besides i have more time than money.
thinking 45 degrees?  top couple fins leaving 3 on bottom?
yeah am anal bout this bike.  bought it new in 74 and rode and raced it.
just cant kick it anymore cause of busted up ankle.
want to ride it on occasion...it is fun.

[garyajaz]

finished.
first head took 2 hours.  second and third  took an hour each.  the holding and centering plate took longer than both.
have the all stainless 10 mm releases  (USA) from vulcan.  very nice looking units
no plastic.
used a hole saw in mill to cut away fins.  glued some wood between fins to keep vibration to min.
came in at 30 degrees and only had to take out top two fins leaving rocker box boss in tact.
thread length is .360 and meat is .5 so when open the tip is flush with the wall of combustion chamber.
not running yet cause am going with new guides also.
yeah, i did have some pro help...  i going to trade use of his machine shop and some help
by resealing a vintage flat track motor for him.. (old huskey in home made frame).

will be nice to be able to kick it over.  at 80 inches some times it would just stop on compression mid kick.  will post when finished.  thanks for the suggestions.

oh and correction it has the large EXHAUST valve.

[garyajaz]

[/img]

[garyajaz]

heads are sand blasted.  raw iron.  after new guides installed will paint high heat semi gloss black
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[FSG]

here's a hand

[garyajaz]

WOW that was quick.  and thanks.  was wondering why the pix with the wood fin seperators did not post.  i went to photobuckett and you already fixed it. now thats service.

[Hillside Motorcycle]

Looks like a nice job.
Scott

[garyajaz]

thanks Scott, especially coming from a pro.
do you think the wood fin dampeners was overkill?
i kept the jig and can probably do them at home now.

most want dual plugs.  i wanted to be able to start it.
just finished clearanceing the rocker arms (they were bumping the collars due to the high lift)
new bronze alum guides on way.  will assemble sat with any luck.
and fire it up monday.  will post proud pix of me (hopefully) kick starting it...
thanks for the tips.

[Hillside Motorcycle]

thanks Scott, especially coming from a pro.
do you think the wood fin dampeners was overkill?
i kept the jig and can probably do them at home now.

most want dual plugs.  i wanted to be able to start it.
just finished clearanceing the rocker arms (they were bumping the collars due to the high lift)
new bronze alum guides on way.  will assemble sat with any luck.
and fire it up monday.  will post proud pix of me (hopefully) kick starting it...
thanks for the tips.

Oh, it may have been, but if that was making you comfortable, allow you to concentrate on doing a nice job, then no.
Scott

[prodrag1320]

when we install releases,we only put a 1/8" hole into the head,with the way youve got them,if the reslease falls aparts,your screwed,the parts will fall into the combustion chamber

[garyajaz]

the 1/8 hole was also my plan.  the meat of head is .5
the threaded part of release is .360
when release is opened its .5
so no room.  i could have got the extensions that put realeses out one inch and went that route.
but it would have stuck out and be in way and look bad.
my concerns were lessened when i looked over at my 1977 IT yamaha.  the head of its release is inside the chamber.
has been for 32 years. 
work on dirt bikes (restore) constantly.
never seen a release come apart yet.
flattracking the bultacos we used the release as a brake going into corners.
they got used way more than just for starting..

if it does fall apart  i am sure the piston will close it (lol)

have you seen many drop?
(dont make me stay up nights)

[garyajaz]

interesting you said before you put them on plug side.
too late now.  but for my info do you have a picture of the set up?
do you use the extensions or make some stand off?
inquering minds want to know.
the 10 mm vulcan releases are the shortest thread ones i could find.
they also are fully stainless and look well made.  better than the plated and blue plastic capped ones.

and yes, i was disapointed when drilling pilot hole there was not enough meat to do the safe way..