New cylinder head prototype!

crmachineman

crmachineman

New Member
Hey everybody! After decking the jug by about .100", adding an additional bottom gasket, and re-machining stock cylinder heads to test different combustion chamber shapes, I decided to make a totally new head from 5 inch diameter round stock. Of course, it incorporates a squish band, which hopefully you'll be able to see in the photos. I deck the cylinder jug so that the edge of the piston is flush to the top of the cylinder, so basically, the gasket determines the squish clearance. After test driving it, I'm pretty happy about the power. The new head really seems to keep the engine cool, as there was no sign of detonation. In comparison to the stock heads with the high compression modifications I did made it so you could only go top speed for brief periods, before head temp. rose too high and then detonation would start, and I'd have to back off on the throttle. I'm thinking about possibly making some more for other people to try out. I just need to do some more testing to perfect it, if possible. I took the advice from some others on this site; I made the head so you could use stock studs and spark plugs.
.xx.
-Fred
 

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Yeah, I put some aluminum deflectors attached to the exhaust flange. They might help a little. Now, with this head, I'm not so worried about overheating.
.duh.
-Fred
 
Hi Crmachineman, well done. Looking at the pic of the underside, the chamber looks quite simillar 2 the RSE head I'm using (Pentworth chamber). Wot piston crown height is the squish band cut for. Cheers
 
When you get that head PERFECTED! sign me up, I want one! for this,or this
How much you gonna ask fer one? you can check out the 1911 Indian on the thread title'd "Blood Thursty" the Sportman Flyer is a slow work in progress as $$ for this thing and the quality parts I want for it are at odds, but all my bikes get the best of the best.
You have some very good!! ideas that could take you far in this part of the M/B world, keep up the good work!
 

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Awesome bike! Yeah, I can see what you mean, you want the nicest parts. I'm not sure what they will cost. I'm pretty sure they will be affordable though. When I have everything figured out. I'll put that stuff up in the swap&shop section. I want to make sure I don't violate any rules by talking about sales outside of the swap&shop section.
-Fred
 
truckd said:
When you get that head PERFECTED! sign me up, I want one! for this,or this
How much you gonna ask fer one? you can check out the 1911 Indian on the thread title'd "Blood Thursty" the Sportman Flyer is a slow work in progress as $$ for this thing and the quality parts I want for it are at odds, but all my bikes get the best of the best.
You have some very good!! ideas that could take you far in this part of the M/B world, keep up the good work!
Click to expand...

Uh, Oh! Your bike frame seems a bit restricted for space above the engine. This head is not an slant angle spark plug. I'm thinking there could be a problem with the spark plug location of this head. Is there anyway the engine mounts could be lowered? I hate to mention that though, because clearly, that would mean quite a bit of work to change.

-Fred
 
I understand!! you can P/M me ( private message me )and I'll give you my e-mail add.
Thanks! for the comps, right now I'm going to use a Puch 70cc Hi Hi comp head tomorrow I will hand it off to my Dad to drill out 6mm holes to 8mm in the head, right now I'm doing R&R on carbs thinking about Dellorto 15.15 mm, but Dammnn!!! that head would look good on that Indian, lots of realistate in the frame to except it too.
Probably not enough room in the Sportsmanflyer but the Indain Oh yah! check my thread Blood Thursty for more pic of the engine in the Indian, I have the cylinder and head off but you could still judge hight
 
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Huh, alright! I'll definitely check that thread about your blood thirsty Indian. Sounds really good. I'm totally in love with those BTR's. I'll probably be selling decked cylinder jugs soon as well, as that is needed to bring the head down far enough to create the "squish" clearance. I think I'll also be providing straightened and trued crankshafts as well. Both those parts will be very inexpensive because it's a matter of a very quick little alteration to an existing stock part.
It's nice to see such enthusiasm about cool things. Also, thanks for the encouragement.
zpt
-Fred
 
Well I hope we don't have to waite very long because I also have a tribute Flying Merkel in the closet (literally) that I'm collecting parts for,I have had the head tube re worked as it was at a wrong angle, this one too would fit your proto type head
 

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crmachineman said:
Hey everybody! After decking the jug by about .100", adding an additional bottom gasket, and re-machining stock cylinder heads to test different combustion chamber shapes, I decided to make a totally new head from 5 inch diameter round stock. Of course, it incorporates a squish band, which hopefully you'll be able to see in the photos. I deck the cylinder jug so that the edge of the piston is flush to the top of the cylinder, so basically, the gasket determines the squish clearance. After test driving it, I'm pretty happy about the power. The new head really seems to keep the engine cool, as there was no sign of detonation. In comparison to the stock heads with the high compression modifications I did made it so you could only go top speed for brief periods, before head temp. rose too high and then detonation would start, and I'd have to back off on the throttle. I'm thinking about possibly making some more for other people to try out. I just need to do some more testing to perfect it, if possible. I took the advice from some others on this site; I made the head so you could use stock studs and spark plugs.
.xx.
-Fred
Click to expand...

Very cool, great looking head you made there! If I had not already bought and installed a Puch head, I would most certainly be interested. And also Fred, you bring up a good point. These engines can and will detonate. Some people seem to doubt that this is possible with these engines, but It does sometimes occur.

I have been thinking about why some of us have this issue, and others don't. And think there are a lot of variables. Such as rider weight, final gear ratio, and terrain, these all play a part in building heat in these motors. With air cooled engines, big fin heads, colder spark plugs, and higher octane fuel, all help with this. Not to hijack your thread Fred ( ha ha ) But I am also glad to report that my detonation issues seemed to be resolved now. But it was no small feat, the head I just installed ( over twice the fin area of the stock slant head ). And a much colder plug ( B9HS !! ), and 93 octane premium, has FINALLY gotten rid of this troublesome detonation completely!! WOO HOOOO!!!!
Peace, James
 
truckd said:
Well I hope we don't have to waite very long because I also have a tribute Flying Merkel in the closet (literally) that I'm collecting parts for,I have had the head tube re worked as it was at a wrong angle, this one too would fit your proto type head
Click to expand...

Alright, everybody, especially you truckd. I've got good news. In a few hours, I'll be putting up two early production heads for sale on Ebay. I've got a little Ebay store where I sell all my funky things. I happened to have enough stock for about 4 heads, but if there is the enthusiasm I suspect there is, I'll be making more right away! I've done some good road tests and am very happy with the design. The combustion chamber is actually a very simple shape. In my tests, I found that this simple dome style head with a squish band produces the most power with less detonation risk. The weather yesterday was really hot, so it made for really good testing circumstances. The engine runs much cooler. You can tell just by putting your hand near the engine after a hard drive. I've got a lot more to talk about these things, and maybe I should do that in the swap shop section, so I will do that in the next couple of days.
Thank you all for such great support!
.duh.
-Fred
 
Okay guys, I just put in a thread in the swap and shop section. The link to my Ebay store is there. I only have two for sale right now, but don't worry, I've got enough stock for another two, but I'll order some more material soon.
Thanks,
.xx.
-Fred
 
Hi Littletinman,
I just put in a thread in the swap and shop for the new head. I'm not sure how to PM you, my apologies, I'm a old guy!
zpt
-Fred
 
Hi Crmachineman, I'm getting old 2, (50) & computers give me grief. I like how u used zero deck height & use gasket thickness 2 set squish. Make it easy 4 people that dont have measuring equipment. If I didnt already have the RSE head I'd have already ordered of u. I hope u get 2 doing cranks as well, like u spoke of b4. As yet no one does aftermarket cranks & if well designed & made I think a lotta people would want. I know I would. Hope u do well with it all. Cheers
 
Yeah Man!
No doubt, I'll definitely offer that stuff. Hey, since I have to do it for my bike, I might as well make extras to share with other motor bike enthusiasts.
Thanks Ivan!

.xx.
-Fred
 
Cool,,, way cool, I'll look forward 2. Sometime in the future I'll have 2 check my crankpin DIA. I thought they were all the same til Headtrauma told me otherwise recently. Good luck with it all man. Cheers
 
For anyone purchasing 1 of these heads, the stock head gasket is about 0.030" in thickness, which is also the normal squish clearance used, so with zero deck height & a stock head gasket u'll b right on the money. Good design feature crmachineman. Cheers
 
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