Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties About big intake valve

About big intake valve

Moderators: Curt!, Pa

Post Fri Oct 14, 2011 5:42 pm
JON

Posts: 98
Location: Helsinki, Finland
Got new cyls from Kurt, and KNS inlet set. After some milling and head (mine) scratching have to ask.
Did valve stems to fit orig retainers, don't know yet if they can do. Will they crack?.. Anyhow, assembled them by this: put heads on without gasket, just snugly to see if in-valve meets head. In start did. Several times re-do and grinding the pocket where touched.. Finally no contact. Put copper-gasket between and crancked. No sound or feel of contact.

Will this be enough? Didn't modify pockets otherwise. Just put engine to roll?

JON

Post Sat Oct 15, 2011 5:50 am
jib

Posts: 575
Location: devon,england
plasticene on head of valve , make sure 120 thou of inch clearance between top of valve and head
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Sat Oct 15, 2011 4:03 pm
JON

Posts: 98
Location: Helsinki, Finland
Would appreaciate some more advice bout that plasticene, and how to do it.
In this case-of-trial only edge of valve head was too close to pocket's curve so I don't know how it is in other area. Maybe that .12" maybe less or more.. I used a pencil as a marker (and hand to feel when turned engine). Should I bring heads to a specialist for milling or just grind more to clear? That 3 mm is clearly more than it is now at valve head edge. Where this 3 mm comes from? Something to do with gas-flows or just temperature based?

JON

Post Sat Oct 15, 2011 9:44 pm

Posts: 975
Location: Markt Einersheim, Germany

Jon,

Go down to local toy store, and get a can of "Silly-Putty".

George

Post Sun Oct 16, 2011 1:47 am
jib

Posts: 575
Location: devon,england
hi jon ,
stick a peice of plasicene on the valve over 120 thou thick and protruding on the side with head next to it, with the head on and a used/compressed head gasket and the valve adjustment correct , turn engine over a couple of times.
remove head.
the plasticene will either be deformed or as original.
measure depth of plasticene by cutting down to the valve to reveal a cross section.
grind out any high spots in head and repeat till ok

think more about flow than expansion, althougth a certain amount must be to allow for the valve ''jumping '' about.

i read in a kr tuning manual that its 120 thou for inlet and 80 thou for exhaust.

regards jib
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Sun Oct 16, 2011 3:56 am
JON

Posts: 98
Location: Helsinki, Finland
Thanks for good hints and info!

JON

Post Mon Oct 17, 2011 12:08 pm

Posts: 766
Location: CA USA
George,
I misplaced my toy putty, so for the past several months I've been using plumbers putty with good results.

Post Mon Oct 17, 2011 8:48 pm

Posts: 975
Location: Markt Einersheim, Germany

Dog....

Thanks for that!.

George

Post Wed Oct 19, 2011 9:48 am

Posts: 329
Location: north central Ma.
Around here we have.
Silly Putty (comes in a plastic Egg)
Play Doh (comes in a can) http://www.catalogs.com/info/bestof/wp- ... laydoh.jpg
Plumber / electricians putty (called money poo in the trades) (come in a stick /bar)
Clay (come in a stick /bar)

Play Doh works the best it sticks just enough but not to much in fact we used to use it to align the radiation shielding at a place i worked. I'd travel with it in my tool box and airport guy would alway take it....guess it looks to close to C4? But i never got asked about it it would just disappear from the lugage... :roll:
"Smok'in the competition NOT Tobacco"
"Transplant organs, Don't bury them!"
Why dwarf? 5/8 scale race cars! http://www.dwarfcarracing.com


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