4 mil storker crank questions?

[jas250r]

I need to replace the crank in my 88 spacer plate motor. Cylinder has been ported for this setup and has been decked. I'am debating between another oem crank or a 4-mil hot rods crank. What's the typical life of the hotrod stroker cranks. What do you need for these cranks? diferent spacer plate? I have heard of some good power gains, but where, most on top, more bottom end? the cylinder i have is ported for mid and top by rb racing. running a esr 5 and a 40.5 that's a buddies, 38pwk is the usual.
i just need some advice. i have ran 1 hotrods crank and it lasted 1/2 as long as this oem(with milder engine mods)

[morse250r]

call robert he will tell you how to set it up he just did one for me and a buddy this past winter we both went for the esr 4mm strokers i have heard to many bad stories with the hot rod cranks on the 250rs esr uses the prox rod you can send them your crank or buy a complete i sent in mine and my buddy bought the complete ....... they are more money but what will cost more a few more bucks on the better rod or after a rod breaks buying new crank and piston and maybe cases just my thought

[Dave83]

Your cylinder has to be ported to match the stroker setup.Another drawback is case trenching to allow the stroker crank to rotate in the cases.Ive ridden stroker bikes,power was smoother than normal,alot like a power valve engine.Personally,unless i was building a wide open play/drag bike,I wouldnt waste the money on one.

[GOTFEAR]

i put one in my 250r and added 2 mill spacer ran like crap undependable power all over the place i was told i needed a cylinder set up for a stroker

[havinnoj]

You can't just drop a stroker into the jug you have now or the timing will be way off. OEM is better out of the box, and Hot Rods are wobbly as hell. If you true and weld them, they shouldn't give you problems. And for half the cost by the time you're done it's a pretty good deal.

[wilkin250r]

Let me just repeat what others have said. You can't just "drop in" a stroker crank. It throws all your port timing off.

Strokers are great engines, but it takes a lot of work. You need to plan out the whole engine, especially the port work. Most often, when a cylinder has been ported for a stock stroke, it can't be re-ported for a stroker. Certain areas have been cut too far, it's almost impossible to "add metal" to those areas to be used with the stroker crank. You need a clean slate.

As a general rule, you have one of two choices. Either go with the stock stroke, or get a new cylinder to get ported specifically for a stroker.

[jas250r]

yeah i think i will go with another oem crank, thanks for the help. i knew about port timing, but just figured that rob knew what to change so i could use the existing cylinder. unless i misunderstood him. thanx

[C-LEIGH RACING]

RB Racing ?? that Robert Batista.
Neil

[jas250r]

yeah your right neil.

[morse250r]

i was talking about robert barnes r b racing from lansing

[C-LEIGH RACING]

Originally posted by jas250r
yeah your right neil.

Last year talking to Frank B, he said his dad did port work.
We ran with Frank national TT 07 season & this year his younger borther ran with us. Both them boys look just about alike.

Roberts got to do good work. When you got a wife thats an outlaw sprint car champion, I'd say your pretty deep into racing.
Neil

[1promodfan]

I was reading this post.....I know its a little old, but I have the same question. Should I get a 4mil crank or not? Is it good for just all around riding? I'm going through my whole motor and not sure to go 4mil or not. I know I just got the new ESR top end, but if I decide to go with a 4mil all I have to do is send it back and get one thats been ported for a 4mil. Also, a lot of guys say OEM is better than a Hot Rods.......whats the deal there?

[C-LEIGH RACING]

Theres a lot of different types of 250R engine builds & you can go from a cheap set up to as much as anyone would want to spend.

As a rule of thum, building a 250R & looking at maintaince, I would rate the stroker as over the edge.
Not so much over the edge you wouldnt ever think of doing one, but just that its not a normal engine & has to be treated as such.
How you run it or what you intend to use that engine for should be the first thought before you ever turn a bolt.
Running wise, power output wise, probably be a bunch of stroker engines out there get smoked by a good 310 or 330 with the right rider on its seat, but, the same is true for any build be it a 2 stroke or 4 stroke.

Look at yourself first, your riding level & then spend the money.

I can tell you this much about a stroker crank, help you decide, those stuffer tins on the outside is what will be the downfall on a stroker crank, getting them to stay in place is hit or miss.

Billet stroker crank would be the route to go & no worries, but better get out the billfold.
Neil

[machwon]

Originally posted by 1promodfan
I was reading this post.....I know its a little old, but I have the same question. Should I get a 4mil crank or not? Is it good for just all around riding? I'm going through my whole motor and not sure to go 4mil or not. I know I just got the new ESR top end, but if I decide to go with a 4mil all I have to do is send it back and get one thats been ported for a 4mil. Also, a lot of guys say OEM is better than a Hot Rods.......whats the deal there?

I don't think there's enough time on the hot rod stroker cranks to give a true opinion. I personally have one and have installed a couple others and 2 ESR OEM versions too. The hot rods one I have has 1 year on it with no issues. No other issues from either the Hot rods or ESR strokers I've done either. In 2008 anyone who needed an R crankshaft went with a 4mm stroker from my shop. I honestly don't think you will have an issue. If you need a crank I'd spend the extra on a stroker. Of the motors I've done its been adding 4-5 hp on each one vs. a std. stroke.

The cylinder needs to be set up for the stroker crank, but once thats done (as long as your builder doesn't give you custom cut pistons and the such), it should be good for the life of the cylinder. Depending on the cylinder, I use either a different spacer plates and/or cut a stock head to accept the added stroke.

There is a lot of fear casted on this thread. Just make sure whoever you talk with, (ESR, or someone who's done strokers) that they know how to set the porting and head for the stroker crank. Hope this helps.

[NOS_350x]

Originally posted by C-LEIGH RACING
Last year talking to Frank B, he said his dad did port work.
We ran with Frank national TT 07 season & this year his younger borther ran with us. Both them boys look just about alike.

Roberts got to do good work. When you got a wife thats an outlaw sprint car champion, I'd say your pretty deep into racing.
Neil

Hmmm, I think your getting your builders and racers mixed up.

Frank Batista From centeral cali?? The one thats now a factory Polaris rider, next to Rath? His dad is Tom, not Robert

His brothers are Timmy and Dustin. I gessing that a Robert Batista isnt going to be the same person that builds Frankies engines.

Not trying to start chit just trying to clear things up for ya.

[C-LEIGH RACING]

Originally posted by NOS_350x
Hmmm, I think your getting your builders and racers mixed up.

Frank Batista From centeral cali?? The one thats now a factory Polaris rider, next to Rath? His dad is Tom, not Robert

His brothers are Timmy and Dustin. I gessing that a Robert Batista isnt going to be the same person that builds Frankies engines.

Not trying to start chit just trying to clear things up for ya.


I guess I stand corrected, I'll find out at the first national race, get my names right.
Neil

[NOS_350x]

I dont think it really matters. just trying to clear things up

Tom marks his territory with a B&B engraveing.

[protrax]

bitd I was sponsored by a very big engine builder ( no names said) I had him build me a big money 4mm stroker motor , complete setup. It was the slowest pos I ever owned for a 250R engine , I would stick to the 89 crank if I were you .

[86 Quad R]

Originally posted by protrax
bitd I was sponsored by a very big engine builder ( no names said) I had him build me a big money 4mm stroker motor , complete setup. It was the slowest pos I ever owned for a 250R engine , I would stick to the 89 crank if I were you .

something wasnt quite right with it then. whether it was in the initial setup or simply not dialed in.

[C-LEIGH RACING]

Originally posted by 86 Quad R
something wasnt quite right with it then. whether it was in the initial setup or simply not dialed in.

You know, it could have been the rider, not everyone can handle a 2 stroke & want to blame it on the engine because its different.
To many things that could be the reason for disliking something other than how the engine was built.

Had a 350R one time broke my foot trying to crank it, POS engine builder, like to put a foot up his,,,,,,, but, I never could bend my leg enough to put my foot up in there, it was me.
Neil

[protrax]

Originally posted by C-LEIGH RACING
You know, it could have been the rider, not everyone can handle a 2 stroke & want to blame it on the engine because its different.
To many things that could be the reason for disliking something other than how the engine was built.

Had a 350R one time broke my foot trying to crank it, POS engine builder, like to put a foot up his,,,,,,, but, I never could bend my leg enough to put my foot up in there, it was me.
Neil

Yeah must have been the rider :rolleyes: thats why I won the Pro Am title that season and 2nd in open pro :p

[C-LEIGH RACING]

Originally posted by protrax
Yeah must have been the rider :rolleyes: thats why I won the Pro Am title that season and 2nd in open pro :p


Ok, now what year? & racing in what series? local or national.
Must not have been to bad a engine, you won.
Neil

[protrax]

Originally posted by C-LEIGH RACING
Ok, now what year? & racing in what series? local or national.
Must not have been to bad a engine, you won.
Neil

Neil what is your problem ? I posted on here I had a bad luck with a 4mm combo in reply to this topic , I did not bash or bad mouth you or anyone here . So tell me why are you coming at me talking trash ? and yeah by the way the championship was won on an old reliable Nac's National 265

[86 Quad R]

from the perspective i got from where im sitting it didnt appear to be a bash. "it could have been the rider" is what i read but, seeing how you won it's obvious it wasnt. :cool: which leads me to think it was in the "overall" setup of the engine that wasnt working for you. those engines are a different aminal to get setup. :huh those port timings can be finiky. ;)

[C-LEIGH RACING]

Originally posted by protrax
Neil what is your problem ? I posted on here I had a bad luck with a 4mm combo in reply to this topic , I did not bash or bad mouth you or anyone here . So tell me why are you coming at me talking trash ? and yeah by the way the championship was won on an old reliable Nac's National 265

No problems at all & I dont think that anything I said could be considered talking trash at you.

All I was trying to do was get you to explain why that stroker engine was a POS & maybe find out what was wrong & who it was built it & see if it was the same one did 2 for me years ago.

We couldnt finish a race with either one, so at the end I was so fed up dealing with them I just held it wide open till it locked up.
Just wondering, but you never said.
Neil

[C41Xracer]

i had a +4mm stroker motor and loved it

[machwon]

Originally posted by C41Xracer
i had a +4mm stroker motor and loved it

I consistently see a 2 ft-lbs tq and 4 hp for the extra 4mm stroke. If you need a new crank they're worth it, but you still need the top end set up for it.

[Buttermilk]

I run a 4 mill / 130.3 crank / rod in my 250R and have done so for several years with no problems.

The 4 mill longrod cranks are drop in and don't need case trenching.

If you set the cylinder up (port timings) and the head (squish, compression) for the 76 mm stroke, it's worth it.

On my own OEM cylinder, with my porting, I have dyno'd my 250R with 56.4 hp, some of which is the +4mm crank.

If you do run a 4mm crank, then it is best to run the '86 style piston to prevent the piston skirt from contacting the crank halves. Running the '86 style piston with a 0.200" spacer combined with two 0.020" gaskets will set the deck height to zero, with a stock OEM cylinder that hasn't been decked.

[addictedtomud]

This post has been helpful to me, thanks everyone...

I have recently bought a quad setup by Baldwin with a +4mm stroker crank and a 330cc non-pv cylinder. It is faster and more powerful than my 350pv with a stock crank (but not as smooth).

So I was wondering if I could have the best of both worlds and swap the pv cylinder onto the stroker motor...but after reading this forum I see that would not be a good idea.

I'm glad I didn't waste my time trying to swap!!