Turning Husqvarna 385XP into a 390XP
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- เผยแพร่เมื่อ 8 ม.ค. 2020
- Turning my husqvarna 385xp into a 390xp, This is my first husky port job so im hoping it turns out good!!!! Thanks to all the new subs, And at the end of the video i meant screamer in a good way not a loud pos!!!
I have a 385XP that I bought new, which is still in near showroom condition. It's a great saw. I did not know that it could be converted into a 390. Very interesting.
I can’t wait for this series dude 👍
Yes hopefully it goes good for me!
@@PoplarMechanic Friend, what is the best max speed for 372 xp oem?
@@Sensei948 max rpm unloaded is 13500
@@Sensei948 i think mine was at 12700 though
@@PoplarMechanic I changed a new air filter, I noticed fuel near the air filter, can it be?
Right on brother, thanks for taking us along on your journey of discovery
Hey no problem, I hope it turns out good. 👊
@@PoplarMechanic 140 psi 372xp good compression?
@@Sensei948 it sounds low but I have heard the 372s stock are at 140psi, if it cuts good it should be fine. My ported 372 has 200 psi, it also has a cracked intake boot right now too, 😆 hope that helps
@@PoplarMechanic Will removing the gasket increase compression?
@@Sensei948 yes it will, make sure you get a good seal with whatever you use, don't use too much either just a thin layer, there are all kinds of stuff to use, permatex red, yamabond and dirko
great video...thanks for sharing 👊
Thanks scoot, I hope it turns out good.
Fun stuff 💪
I have an a Husqvarna 385 and i going to remanufactured because the piston and the cilinder dead and mount the 55mm cilinder not the 54mm cilinder and turning to 390, i am very exciting to try the turning. Thanks for this tipe of videos.
Ya its pretty cool, its like a big bore cylinder, thankfully I've learned alot more since this video, its a learning curve this stuff
Nice video, I always wanted to know Highway vs Meteor on the 390XP
Ya they are close, I'm going to go with the hiway for this one. Thanks for watching 👊
I’ve heard the 385 top end ports really good. I haven’t ported one yet but it’s basically a 372 but bigger. Good numbers for a 372 are 98/117/80. Also if you haven’t found out already AM cylinders like to chip when you grind on them. Which is why most wont port them.
Good to know thank you, so my exhuast is at 96 atdc intake opens at 102 abdc and I was just working on the blow down when I had to leave it seemed way high like 32 but I'm gonna double check. So exhuast is 168 duration and intake is 156. I kinda like where intake and exhuast are, Should I raise the transfers? And what do you think of lowering the intake thanks.
Exhaust at 96 is too high for a work saw. I only build work saws and have never had a exhaust that high. Intake is good. You should do a little more machine work and lower the jug. Get the exhaust down to 98 and if the intake lands at 80 that works well. Definitely raise the transfers up. You’ll want a blow down less than 22. But like I said before I’ve never built a 390. Any bottom fed transfers like a longer blow down around 20 degrees.
@@yotaismygame ok because I'm not doing any machine work I am the machine lol ironhorse put his at 96 I believe, Its interesting a hiway 390 cylinder on a 385 that's what it gave me. And I know it's right now because my wheel was off by 3 degrees for some reason so I figured it out by duration. Do you think maybe the large blowdown compensates for some of that lol I dont know I'm still in the process of figuring stuff out. Also say my blowdown was 32 so from when transfers open to 96 degrees atdc would I add that together to get transfer duration?
@@yotaismygame or no I meant 96 +32 is transfer open 128 degrees atdc so my tranfer duration would be 180-128 = 52 so 52 x 2 would be 104 total transfer time? That seems low.
To calculate BD take the transfer height and subtract the exhaust height. Example: 120 tr height - 100 ex height = 20. BD of 20 degrees. Often you can get an idea of what to time a saw at by the stock numbers and see how it runs. I’d be surprised if the BD needed to be longer than 25 degrees. The only saw I’ve built with more than that was a Makita 7900. For some reason they like BD around 28. But being the 390 cylinder is so similar to the 372 I bet something close to 20 would be better. If you have multiple pistons and you don’t care about ruining one you can grind away the crown of the piston where it goes over the transfers. Thus opening them sooner. Could try that before you grind on the cylinder. Also if you need any machine work done I don’t mind helping guys out for a small fee.
nice video. I have a question. If u already have a 390xp and u just so happen to have access to free oem 385 piston and cylinder. would the 385 piston and cylinder bolt on directly to the 390 ??
Yes I believe it will, also I was fairly new to this and made some mistakes when I was timing it, so if your looking to grab numbers there are plenty of youtube videos that show you how, but if your just looking to bolt the 385 piston and cylinder on the 390 I don't see why it wouldn't work. Thanks
A man as got to keep busy
I build adapters for the degree wheels. Harvey has a few I built. Kensie also has some I sent.
Awesome good to know, ill keep that in mind this winter when I got time to work on saws.
@@PoplarMechanic
Another option, probably more convenient for you, is to have someone with a lathe turn some down for you and drill and tap them for whatever you need. As I'm in Canada, it's probably too much much hassle for you guys below the border.
@@peaceriverpowersaws9534 im in Canada man .
going to do a 385 soooon
I have a question for anyone that knows. I bought a 385xp about ten years ago, for occasional use on my property. I’ve always run 50:1 mix, because I believe that’s what the manual said. So far no problems. Should I be running a richer mix, say 40:1 or 32:1?
Thank you! Great video!
50:1 I find is good for the stihl top handle saws, for your 385 I would run either 40:1 or 50:1, it's up to you but I've ran both in my 385 and it likes both, I mainly run 50:1 now. It's less oil but if the manufacturer calls for it then that's what i would do.
Poplar Mechanic I appreciate the response. Thank you
When you grind on the intake floor 74 will become a larger number not a smaller number from my understanding
Ok Ben your making me think, I love it, I'm gonna have some lunch then head to the shop to get the work in front of me it's the only way I'm gonna figure it out. I get what your saying. I'll do a video on my findings.
Yes you are correct thanks for commenting, the only part I cant figure out is what he was talking about pushing it to 70, maybe he did mean after bottom I dont know.
I’m thinking he was thinking something diff than he was saying or just the way he reads the wheel is different from us.
@@mercoldswfo yes your right, you know I dont think I have to touch the floor on this one. The difference between intake closing and exhuast opening after tdc is 19 degrees that should be perfect. It needs that to build compression.
Taking too much from the base of the intake port will really detract from the saws performance.
don’t be fooled by if it’s open longer it’ll take more fuel and air, and run better.
Do you think 70 degrees closing after tdc is too much? It would be a change of 6 degrees, I will convert that to thousands today. I'm thinking it will be somewhere around 20 thousands from what I've seen. Thanks for commenting.
Hey I did some research I made a mistake, if anything I may just take 1 degree from the floor, thanks again.
Poplar Mechanic hi, that’s no problem, it’s just a popular misconception that taking off material will help, to be honest many cylinders need a bit taken off, but I have more often than not had to add belzona epoxy to build the port up to get the correct figures.
Love your videos pal, keep up the great work.. 🏴👍😁
@@salvtec hey thanks alot your advice means more than you think 👊
74 degrees is 148 intake duration, 70 degrees is 140 intake duration. Correct me if I’m wrong
Hey Ben I have a question for you, So I found my exhuast duration but it isn't lining up with the math, Heres what I mean, exhuast opens 93 atdc and closes at 81 degrees after abdc initially I thought to add those numbers together but then realized something wasn't adding up so I counted the difference between those two numbers on the degree wheel and came up with 168 degrees. Then added the intake and the time the ports were both closed and hit 360 exactly. Sounds right but heres the problem 168/2=84 180-84 =96 wich should be my opening atdc, What am I missing here?
So I think I figured it out if it opens at 93 atdc 93x2= 186 360-186= 174 so 174/2 =87 180-87 is 93 so I guess I do just add the numbers, Doesnt that seem high for exhuast. Anyway I guess the mistake must be on my intake I'll take a closer look.
Poplar Mechanic 93+81=174 so you’re not 180 from each other I think. You may be off by 3 degrees which would make the numbers 96 and 84. Yes 93 is crazy for exhaust. From what I’ve read that’s like a number that you’d need a tuned pipe for. Ironhorse was saying go above 96 and it’ll rev like mad but have no torque. I think you’re at 96. You basically want the pointer to end up at the same spot when you wheel it over. Again I’m not an expert but when I do it that way it works every time for me. When you’re at 93 cheat your pointer to 96 atdc and see how it works out for intake and exhaust to add to 180
@@mercoldswfo ok will do, I made a video that explains a few different conclusions that I came to but I dont want to post it until I make sure it's right lol. But I wish I could show you, Anyway I'm determined I'll figure it out, so my duration is 168 like I counted on the wheel from open to close wich makes sense 168÷2 =84 180-84= 96 atdc. So that's it then I'm off 3 degrees tdc I dont know how it happened. But it makes sense because counting the degrees from open to close stays true no matter where tdc is. Anyway that's a good number for exhuast lol. Thanks for the help man sometimes it just helps to get another point of view.
Poplar Mechanic Ben.timmers@yahoo.com if you want to email me. It’s always be nice to have someone to bounce ideas back n forth with. I’m waiting for iron horse to pump out some more porting videos. That mans got some knowledge.
If you watch the video with Harvey, he measured his intake at 72 and planned on changing it like 2 degrees which would make it 74. He said he is going for 70 but I think he was going ABDC for the way of thinking. So 70 ATDC is 110 ABDC on the flip side. I think I wouldn’t go more than 2 degrees intake timing on your cylinder.
Hey thanks for sharing, I was just studying his video, It seems that he did say he was going to push it to 70 and I may be wrong but I'm pretty sure it was 76 degrees after tdc the intake closed. Shortly after he says he is going to take 20 thous off the floor and at 15 thou per degree that would be just over a degree. So maybe I just leave the intake timing in my case I dont know I'll email him.
Also I agree with you on the 2 degrees 6 seems alot lol even though I'm starting to figure this out there is lots to figure out. Thanks for the advice I'm not cutting just yet.
Poplar Mechanic I’m just learning myself too, thanks to Harvey. It seems the more I learn, the more questions I have. It’s both fun and frustrating at times. So far I did 3 poulans and a top handle power Mac 320. Now I’m onto a MS200T. I plan on doing a base gasket delete and just opened up the ports a touch. Think I’ll end up .022” squish 98exhaust 127 transfers and 76 intake. I wish I had tooling to raise transfers but I don’t fully understand that part either.
@@mercoldswfo lol I know its complicated. On this saw after i add everything up i get a total of 365 degrees lol. My 200t turned out damn good with only widening the ports, I did nothing to the roofs or floors I should put the wheel on it and see what it's at.
Poplar Mechanic yes if you do let us know. Also, when I check timing say exhaust at 100 first Ray of light spin it over 180 to first ray of light again and see what that number is if they don’t add to 180 then you are off on bdc. I’ll just fudge the pointer over a few degrees and re do it till I add to 180 so I know I’ve got accurate port timing. Similar to using a piston stop to find tdc.