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- 17,175
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- Crafers South Australia
Z's HPI Baja 5b/5t build
- Thread starter Z.hb71
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- Messages
- 19,475
- Thread starter
- #422
Wasn't a short cut by any means. Wasn't aware of this shite. Beyond my why on Earth anyone would make a head like thatSo lessons learned???don't short cut!
- Messages
- 17,175
- Location
- Crafers South Australia
Hear you ?
Put it on Ebay sell the head ?? mod (drill )
Old one or put the $$$ towards alx head??
Put it on Ebay sell the head ?? mod (drill )
Old one or put the $$$ towards alx head??
- Messages
- 1,130
- Location
- Portland, Oregon
I just can't help but feel that your "make it through break in" gasket stack idea is only going to cause more heart ache. You're going to spend a ton of time and more money making the gaskets on a hope and a prayer that they won't fail during warm up.
There's also expansion to consider. If you gap your gaskets just enough to clear the head from the piston, there's still a chance that once everything warms up and expands, you might have a piston strike on that head's ring. You can either hit your mark, or miss it and cause a catastrophic failure. These aren't things you can plan on getting right without a lot of experience and accurate instruments.
If you want, I can ask around locally to see what it would take to mill your old head for a decomp valve. I'm sure I can find someone who will do it for me for stupid cheap. If I can get a good price, send me you head and decomp valve, and I'll help pay for the work. I just don't want to see you chasing your tail and doing something to make the situation even worse!
There's also expansion to consider. If you gap your gaskets just enough to clear the head from the piston, there's still a chance that once everything warms up and expands, you might have a piston strike on that head's ring. You can either hit your mark, or miss it and cause a catastrophic failure. These aren't things you can plan on getting right without a lot of experience and accurate instruments.
If you want, I can ask around locally to see what it would take to mill your old head for a decomp valve. I'm sure I can find someone who will do it for me for stupid cheap. If I can get a good price, send me you head and decomp valve, and I'll help pay for the work. I just don't want to see you chasing your tail and doing something to make the situation even worse!
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- 19,475
- Thread starter
- #425
Oh crap.......good point. It the piston smacks the hell out of the head at whatever rpm, well there's a piston and cylinder. Thanks for the offer, I'll think about it. First I want to try and get rid of the rcmax head. Hopefully I'll be able to sell it quick, I'll try some big bore groups on Facebook and I'll ask on face book if anyone's got an alx head for sell before I go ahead
and machine the existing head. ??
- Messages
- 1,130
- Location
- Portland, Oregon
Sounds good. Ask around and see if you can get the head that will work. I'll poke around locally within my group of motorheads and let you know what I can figure out for machining costs here locally. PM me some pics so I'll have something to show them. I know you have pics here somewhere, but it would be easier to have a local copy and not have to go digging in the forum.
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- 19,475
- Thread starter
- #427
I'll have to take new pics In the morning, i myself lost em lol
Polar_Bus
Well-Known Member
- Messages
- 754
Z, now that i see a pic of your head dome , im in the opinion that your only solution is a 1pc aluminim spacer to fit between the cyl and head. Like i commented in our PMs my major concern is establishing squish, and where we will end up with compression. PM me your piston dia and the diameter of the head dome only, not the overall OD of the head male fit. I might be able to machine a custom spacer out of aluminum.
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- 19,475
- Thread starter
- #429
tbh, im going with AnubisBC. It is more less a band aid. the head will not work and will need a spacer, every time i take the head off for whatever (IE ring chang) ill need to replace this spacer, which is more $$$$ over time, now, over time ill end up having spent way more money than the alx head and has a head that is band-aided. its not that big of a deal tbh. i cant slap it all together right now so i small delay is not a big of a deal, also i don't care if im running in the winter thru the snow, a little water n ice won't stop me. plus if i sell the motor, the next owner is stuck with a band aided head and is gunna need to buy the copper make a spacer ect ect.
- Messages
- 2,044
- Location
- Long Island, New York
As i suggested - Take it to machine,cycle anywhere you can get some advise on what to even do at this point or if its even worth it.
It's noble to keep on but sometimes you need learn when to cut your losses or quit/ OR get real advise from someone who can actually see what you have and advise you on best way forward.
We can see your pictz but it's still different then it is in person.
If knew what i do now,man things woulda been different!.
Live and learn, Good Luck. ?
It's noble to keep on but sometimes you need learn when to cut your losses or quit/ OR get real advise from someone who can actually see what you have and advise you on best way forward.
We can see your pictz but it's still different then it is in person.
If knew what i do now,man things woulda been different!.
Live and learn, Good Luck. ?
- Messages
- 19,475
- Thread starter
- #431
The only way is to make a spacer or mill it down. Milling I'll probably be going into the decomp valve hole, and spacer has to be 100% on point so I can set squish correctly and not bang the hell out of my piston @ WOT. This head was supposed to be a drop on part, so modifying it or whatever totally defeats the purpose, I could have just machined my old head. So it's a waste of time/money. I'll put it on some of the fb groups I'm in and hopefully it will sell quickly. After that I'll see about getting an alx head or machineing my original Athena head.
- Messages
- 2,044
- Location
- Long Island, New York
This thing just keeps snowballong.
Your going have see if cost and time still makes it worthwhile in the end,you know what I mean.
You've dedicated a lot of time and money to make something you wanted,props for that. ?
At least now see not everything happens the way we would like.
Lol,next time just buy the dang engine. ??
Your going have see if cost and time still makes it worthwhile in the end,you know what I mean.
You've dedicated a lot of time and money to make something you wanted,props for that. ?
At least now see not everything happens the way we would like.
Lol,next time just buy the dang engine. ??
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- 19,475
- Thread starter
- #433
Lol. Yep, next time I will just buy it. Was a good learning experience. Now , well, I got to get it running lol. I'm not going to decide what I want to do with it until I get it back together and attempt to run it on gasoline, like I said, my issues and expense were mostly caused by e85.
Polar_Bus
Well-Known Member
- Messages
- 754
I also think you should add base gaskets so as to establish your piston TDC equal to the height of your cylinder. Typically ime, thats the way that most engines are set up. You add a head gasket and the gasket establishes your squish clearence. I don't have deep experiences with Zen's so maybe others can chime in and add more precise info. With your piston exiting the cylinder by 2mm your port timing is probably going to be off .
- Messages
- 19,475
- Thread starter
- #435
This ain't a zen lol. That's how I normally set squish, add base gaskets. The top gasket for the head is Just to seal, nothing else.
Polar_Bus
Well-Known Member
- Messages
- 754
I know you don't have a Zen. I'm commenting that I don't have deep mechanical knowledge of the small Zen weed wacker / chainsaw type engines. All me experience is within powersports engines.
- Messages
- 13,102
There should be a spec for piston protrusion. And normally it only a few thousandths not 2mm. I feel kinda dumb I didnt think if that before.
WOW is that one of the super chainsaw motors you see on the sat when the loggers have their cut off's comp ? . Never seen a intake setup like that ever in my life! looks pretty trick. What is the angle finder take off piece for? Timing ?
are those front tires on the back? do they work good ? Never thought of trying that setup. Learning alot from this build.....Cool!
- Messages
- 19,475
- Thread starter
- #439
Thanks. Not a exactly chainsaw motor. It's based off a ALX crankcase, ALX is a company that makes these big engines for our rc's, and I didn't want to buy one whole (thought I could build one off their Crankcase for cheaper) so i took that and built my own! And that intake system, yeah I bought a silicone 3ply tube that would go under the exhuast instead of the air filter touching it, worked out pretty good. Here
And lastly, yes that is a degree wheel for finding/adjusting/setting timing.
Attachments
Holy crap! Me WRONG! that is not a saw motor! that thing must rip, How long of a run do you get on a tank of gas? Where did you get the Malossi race frame from to mount that motor?
is that a green Integy transmission case? . I bought one and it would not fit worth the beans!!!!. Even the diff housing would not even go in. and Integy would not return my mail and I got taken.
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