Author Topic: Guys with 350s (Read 14160 times)

Grande huevos · « **on:** February 01, 2016, 12:10:06 PM »

I'm torn between rebuilding my 330 or making the switch to a 350.... I know I have to get my cases bored or get new ones but do you think that a standard ESR 5 pipe and a 38 mm A/S carb would be efficient enough to feed that motor? It's not a lot bigger then a 330 and it seems to be working fine for me now... I'm just trying to see what all components that I would need and what I could keep off my curent motor and just swap it over.

havinnoj · « **Reply #1 on:** February 01, 2016, 12:16:20 PM »

Guess that depends on what the "switch" entails. New cylinder and new porting? If you need to get your cases bored, why not throw a +4mm in there with the 78mm piston?

350 would be on the verge of needing a big bore stinger but not a must. I ran a 76x76mm (343cc) motor with a Sparks TT pipe & 39PWK for a dune season and it ran great.

fast350r · « **Reply #2 on:** February 01, 2016, 12:48:23 PM »

I ran a esr 350 with a drag port for a long time , 38mm carb and trx11 pipe , just gotta watch your jetting and temp. havinnoj is right a bigger stinger is needed.

F-Red · « **Reply #3 on:** February 01, 2016, 12:52:55 PM »

I went from a ESR330 to the 350. Kept the TRX5 pipe and the 38mm A/S carb. I did change to the larger UPP intake boot. Runs great.

Grande huevos · « **Reply #4 on:** February 01, 2016, 01:02:39 PM »

Quote from: havinnoj;64024

Guess that depends on what the "switch" entails. New cylinder and new porting? If you need to get your cases bored, why not throw a +4mm in there with the 78mm piston?

350 would be on the verge of needing a big bore stinger but a must. I ran a 76x76mm (343cc) motor with a Sparks TT pipe & 39PWK for a dune season and it ran great.

If I did it I would be getting a new ESR 350 cylinder most likely the engine builder kit sent out for mid range porting.. A +4 crank would be great but I have a perfectly good oem crank that I just had rebuilt with a pro x rod from Duncan not to long ago... I already have a Neil's HD clutch with Hinson basket 01 cr ignition boydseen rad valve....

I'm just going over my options on how I could set it up for more power while still trying to use what I have and spend little as possible out of pocket and not having to deal with the hassle of selling my old pipe and carb or whatever parts Id need to change

havinnoj · « **Reply #5 on:** February 01, 2016, 01:18:03 PM »

Quote from: Grande huevos;64028

If I did it I would be getting a new ESR 350 cylinder most likely the engine builder kit sent out for mid range porting.. A +4 crank would be great but I have a perfectly good oem crank that I just had rebuilt with a pro x rod from Duncan not to long ago... I already have a Neil's HD clutch with Hinson basket 01 cr ignition boydseen rad valve....

I'm just going over my options on how I could set it up for more power while still trying to use what I have and spend little as possible out of pocket and not having to deal with the hassle of selling my old pipe and carb or whatever parts Id need to change

If you're buying a new cylinder and porting it, ~$225 for a Hot Rods +4mm adds pretty great bang for the buck IMO. You pick up about the same displacement gain by adding a +4 as you do going from a 330-350. 78x72mm = 344cc and 78x76mm = 363cc. That's a pretty cheap way to pick up additional power, not to mention the slightly broader power curve. But I hear what you're saying about trying to do it as cheap as you can.

etccb · « **Reply #6 on:** February 01, 2016, 01:44:05 PM »

Or go trx7 esr 100 port with 4 mil crank when you purchase it now. Down the line you can have someone do some port changes if you like but for now dollar for dollar you get the backbone of the engine that you want for the same that you plan on spending right now. They will bore your bare case for free this way too so thats another 100ish.

Tbone07 · « **Reply #7 on:** February 01, 2016, 02:14:36 PM »

38mm will be fine depending on what kind of riding you do. I use a 38mm on my 350 Sphynx for XC riding and it does great

A 40mm will feed your engine better at high RPM, but you'll lose some bottom-end throttle response.

atvcrazy · « **Reply #8 on:** February 01, 2016, 05:47:37 PM »

I would just rebuild your 330 if staying with a standard stroke crank. You aren't going to see enough gain going to a 78 mm bore and at 78 mm with either a new ESR cylinder or old Pro-X there isn't much material left around the water jackets and the 76 mm bore is safer to me for reliability. I would do a 344 cc 76 mm bore 76 mm stroke Esr or pro x

Grande huevos · « **Reply #9 on:** February 02, 2016, 10:05:47 AM »

Quote from: havinnoj;64030

If you're buying a new cylinder and porting it, ~$225 for a Hot Rods +4mm adds pretty great bang for the buck IMO. You pick up about the same displacement gain by adding a +4 as you do going from a 330-350. 78x72mm = 344cc and 78x76mm = 363cc. That's a pretty cheap way to pick up additional power, not to mention the slightly broader power curve. But I hear what you're saying about trying to do it as cheap as you can.

I did some research yesterday and I think I found a buyer for my current pipe,cylinder and carb so I'm looking into the ESR
"4 stroke killer kit". So I might end up just having Eddie do that with the 4 mill 350 and him doing a nice port..... Is your 350 reliable or would I be safer going with a 330 plus all the other goodies of it's reliable I'll def go with the 350 because it's only an additional $100 over the 330.... I'm ust looking for some opinions from guys that have had similar setups... It will mostly be a XC bike that gets ridden only few times a year but we also hit the dunes once a year and that's really where I have my fun with her!

rablack21 · « **Reply #10 on:** February 02, 2016, 10:17:56 AM »

I just built my 363 stroker last year,mx setup. While the more you modify anything the less reliability you will have, they are still very reliable. Tbone and Burn363 both do XC racing with theirs. I race mine mx and Burns used to as well. The motors are very strong and they will hold up just fine for you. Since there isn't much cost difference, go for the 363 set up. I love mine. Like tbone said, the 38mm is plenty for XC racing. You don't need the 40mm. The bottom end will be more responsive with the 38.

havinnoj · « **Reply #11 on:** February 02, 2016, 10:23:47 AM »

Quote from: Grande huevos;64061

I did some research yesterday and I think I found a buyer for my current pipe, cylinder and carb so I'm looking into the ESR
"4 stroke killer kit". So I might end up just having Eddie do that with the 4 mill 350 and him doing a nice port..... Is your 350 reliable or would I be safer going with a 330 plus all the other goodies of it's reliable I'll def go with the 350 because it's only an additional $100 over the 330.... I'm just looking for some opinions from guys that have had similar setups... It will mostly be a XC bike that gets ridden only few times a year but we also hit the dunes once a year and that's really where I have my fun with her!

I never had any issues with that motor. Select a good motor builder and you shouldn't have issues. You definitely get a lot of stuff for the price - link for reference: http://www.eddie-sanders-racing.com/product_p/stage%203%204%20stroke%20killer.htm

Grande huevos · « **Reply #12 on:** February 02, 2016, 10:35:39 AM »

You guys have any Mods done to those 4 mill cranks or just install them straight out the box?

etccb · « **Reply #13 on:** February 02, 2016, 10:39:51 AM »

Go for it grande. The esr cyl at 350 is fine and that is proven by it also being used by more builders today then ever before.

rablack21 · « **Reply #14 on:** February 02, 2016, 10:42:13 AM »

Quote from: Grande huevos;64065

You guys have any Mods done to those 4 mill cranks or just install them straight out the box?

No mods for mine, running straight out of the box.