anybody make em? and why is the combustion chamber shaped like it is? i've seen plenty of other non-hemi 4 strokes that the combustion chamber matched the cylinder. any idea if the head will still be thick enough if this is done?
hemi heads or domed pistons?
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If you send me a giant chunk of aluminum like 6 by 6 by 6 i could go to my neibors and mill one out including fins and all for the fun of it... hes got a cnc mill now.... so yeah and why is the cylinder shaped like that? cause it centralizes the spark and combustion for more power...
Kaptain Krunch
Pro Junk Collector
Does your neighbor also have a g-code generating program? If not writing the g-code by hand will be impossible for 99% of people.
Ill have to ask him but he can do the codes himself... he writes programs for customers for a living... next time he comes over to drink ill ask him all that good stuff... not sure if he got his lathe yet... or if it fell through his barn floor lol....
freak, do you really believe that an under powered engine has the best (well, you didn't say best) combustion chamber possible? if it did, or any low end engine for that matter, why do we go swapping heads? sounds good on your offer. is there a particular billet i should buy for this project? if it is cheap enough i may take you up on this offer! (better find an expensive one, haha)
Lol a giant chunk of billet wont be cheep but it would be pain in the *** but i would like to see this done....it would take a long *** time to do but if it wasnt domed it would be easyer.... But anyway anyone drill and tap there heads for a second spark plug the run a twin cylinder coil?
Also forgot to mention this earlyer so this is a edit... not sure if id be able to cause im sure my neibor dont want a 10,000 dollar electric bill.... and if he did let me it would probaly take longer then i could do for free... if it was a simple square with a spark plug hole and head bolt holes and that kinda stuff it would be easyer but thinkin bout it a hemi head would require a pretty big chunk of aluminum and also if its ohv forget it and calculating the ccs and size of the head would be way to much then i could do some time soon..
Also forgot to mention this earlyer so this is a edit... not sure if id be able to cause im sure my neibor dont want a 10,000 dollar electric bill.... and if he did let me it would probaly take longer then i could do for free... if it was a simple square with a spark plug hole and head bolt holes and that kinda stuff it would be easyer but thinkin bout it a hemi head would require a pretty big chunk of aluminum and also if its ohv forget it and calculating the ccs and size of the head would be way to much then i could do some time soon..
about the price of a new head. http://www.industrialmetalsales.com/69.html
I wasn't jokin till I figured the time Nd money one would have to put in it... And depending on the bore of the engine to get the right size dome it would be bout half thAt block mabeyvsome more. For a lil while ibwas thinking of making my flat head Briggs into a ohv by machining two heads for it. I might draw one up in cad today ifbi have a chance to cause it would be kinda difficult
Russ2251
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jr dragster T
New member
Making billet OHV cylinder heads isnt really something you just take up on a Sunday afternoon lol.
i know, thats why we were talking about it on a thursday, haha. 
no, i'm kidding but yeah. some of y'all/us have been around engines enough to know which chambers work better. the main leg work will be in determining the appropriate alloy for a cyl head based on thickness and other variables. if you find out what the stock head is made of, alloy wise, and can get an alloy with double the strength, you may be able to make it half as thick. etc etc. me, i was just wondering why no one has made them since they have such a rep. tyler, do you use a dome piston in your jr drag?
no, i'm kidding but yeah. some of y'all/us have been around engines enough to know which chambers work better. the main leg work will be in determining the appropriate alloy for a cyl head based on thickness and other variables. if you find out what the stock head is made of, alloy wise, and can get an alloy with double the strength, you may be able to make it half as thick. etc etc. me, i was just wondering why no one has made them since they have such a rep. tyler, do you use a dome piston in your jr drag?
jr dragster T
New member
Nothing domed used in Junior Drag motors. All high compression/super lightened pistons. Hard to see the measuring tape but the piston is only 1 1/2" from skirt bottom to piston top.
jr dragster T
New member
We run one compression ring, And a 3 peice oil ring.
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