ESR ported cylinder; help determine rpm range

[kmfl]

I just bought an 86 and the cylinder has been ported by ESR. Is there any way to tell how it's been ported? Can you determine port timings by measuring from the top of the cylinder down to the intake and exhaust port? I took the head off and did so but don't really want to pull the jug. It doesn't say anything but ESR that has been ground into the side of it. Thanks for any help

[86 Quad R]

i'm no expert by no means but if i'm not mistaken there should be a port designation located somewhere on the underside of the cylinder. unfortunately this requires that you remove the cylinder. :(

[hondamancbr03]

Actually it's very simple....Just buy a degree wheel from a parts store or eBay and pull off your flywheel, mount the degree wheel on the crank (they come with spacers), use a wire under one of your base nuts with it bent over the degree wheel, set the piston at TDC and the wheel on TDC, spin the crank and see what your exhaust and transfers are set at.....It's a very simple thing to do. You can measure down to your transfers and exhaust but you will need two stroke software or someone that has port numbers saved from past experience to say what it is. I prefer to port time my bike with a wheel, it's the most accurate way IMO.

I can send you a picture of the degree wheel i use if you are interested.

[kmfl]

The degree wheel would be best but I have it all backtogether and riding it. Just looking for a "rough" idea of the type of port job. The exhaust is about 1.56" from the top deck and the intake is about 2.26". I didn't measure the transfers. Is that enough info to take a guess? Low,mid or high? Just tring to halfway match a pipe. Currently using a pt 89 race pipe. Thanks for any help.

[1promodfan]

check your PM's..........

[fulltiltrider]

Let me know if the piston is flat with the top of the bore. If not, measure the difference. I'll let you know what the timing is, assuming its a 72mm stroke

[kmfl]

It seems to be 0 deck. The sides of the piston come right to the top of the bore.

[hondamancbr03]

Originally posted by kmfl
The degree wheel would be best but I have it all backtogether and riding it. Just looking for a "rough" idea of the type of port job. The exhaust is about 1.56" from the top deck and the intake is about 2.26". I didn't measure the transfers. Is that enough info to take a guess? Low,mid or high? Just tring to halfway match a pipe. Currently using a pt 89 race pipe. Thanks for any help.

You can degree an engine while it's still in the bike.......

[fulltiltrider]

Ok this is what I come up with. Dont know if you got short or long rod so I did them both.

Short Rod= 184.88* ex / 122.28* Tr 31.30* Blow Down

Long Rod= 184.22* ex / 121.6* Tr 31.31* Blow Down.

That would be a mx port I would say. Favoring low end power. Should work good with that pt pipe or a ct midrange. I like a little more BD timing than 31*. Imo Id move the ex port up to around 188-190 and match it up with a esr 5. It wont have a super strong bottom end but it will fly through the mid and top.


Also, you dont need any software to figure this out. Just a little algebra from high school.


D={180-[cos T squared + R squared - L squared / 2 x R x T] x 2}

T=R+L+C-E
R=Stroke divided by 2
L=Connecting rod length
C=Deck height
E=Distance from top of port to top of jug

Get those calculators out !!!!!!

[kmfl]

Thanks for the info. I really appreciate it. It feels to pull the most in midrange. I wish it had more topend but hopefully the 38mm pj that's on the way may help. How much higher in inches would it take on the exhaust port to get to your recommendation?

[fulltiltrider]

Originally posted by kmfl
Thanks for the info. I really appreciate it. It feels to pull the most in midrange. I wish it had more topend but hopefully the 38mm pj that's on the way may help. How much higher in inches would it take on the exhaust port to get to your recommendation?

haha that is where it is nice to have a degree wheel. I'd have to just plug in some numbers till I get it right doing it the math way. Maybe tomorrow....my brain hurts allready lol.

[hondamancbr03]

Originally posted by kmfl
How much higher in inches would it take on the exhaust port to get to your recommendation?

Don't get lost in the numbers only....The shape of the exhaust port, the angle of the transfers and many others things come into play.

[kmfl]

That's why I probably won't mess with it. Will a topend pipe work too much against the portjob? Like a pt hi-rev or eliminator? Its got a stock reedcage and reeds. Should I upgrade those?

[hondamancbr03]

Every good engine building will tell you to port to the pipe you run, or purchase the pipe for the port you have...The reason for this is if you put a high rev pipe on a bottom/mid range port you can possibly lose HP.......Your engine is cycling the gas best in the bottom and mid range, embrace that and put a good mid range pipe on there (if you don't already have one) and enjoy what you have.

[fulltiltrider]

I agree that I would not try to do it yourself if you never did it before, but I dont think you have to settle for what you have. I dont like esr port work, unless you get one that Eddie did especially for your setup its just another cookie cutter job. The transfers are cut too high for that exhaust number imo, and since you cant put the metal back in, you might as well make it optimal for a setup you can get to. 188-190 will make a nice play port with a more top end style pipe like the esr5 or pt eliminator. Unless all you run in is tight woods, and you have the cash to invest, I'd have it reported. Thats just my riding style though, I like top end power.

[rsss396]

for mid range power I kind of like the transfers high like that, even alittle more would not hurt.
But if top end pull is what your after than 188-190 would work real nice.
Raising the exhaust is the easiest part of a port job as long as you raise it to the correct height.
degree wheels are some what cheap and a dremel with a flex shaft attachment using a small sanding drum would work fine for this.
Just won't help much for other area's of the cylinder.

[fulltiltrider]

Originally posted by rsss396
for mid range power I kind of like the transfers high like that, even alittle more would not hurt.
But if top end pull is what your after than 188-190 would work real nice.
Raising the exhaust is the easiest part of a port job as long as you raise it to the correct height.
degree wheels are some what cheap and a dremel with a flex shaft attachment using a small sanding drum would work fine for this.
Just won't help much for other area's of the cylinder.

I understand your ideas about the transfers being good for that style of port I guess. I like top end power and a blowdown of 31 just doesnt cut it. I've been in the habit of keeping at least 33*-35* of BD on all my builds, but most of my stuff is beyond 190* on the exhaust. My zilla is 200* and 130*.

[hondamancbr03]

This is a very opinion driven subject.....It's best to agree to disagree over port numbers and what we like...IMO

I just put together an LRD engine and threw the wheel on it to see where Alren set a mid/top end motor.
189 E
132 T
BD was low but can't remember what it was.

fulltiltrider I know you would not like a motor like this being the BD was low, but this motor runs great for the rider (friend) and has an old school FMF gold series pipe.

Bottom line....Whatever works for ya.

[rsss396]

I had good luck with 192E - 126T
196 is probably as high as you can go on alky 250r maybe 198 on race gas.

My cr500 trx is 196E - 124T on alky

[fulltiltrider]

Originally posted by hondamancbr03
This is a very opinion driven subject.....It's best to agree to disagree over port numbers and what we like...IMO

I just put together an LRD engine and threw the wheel on it to see where Alren set a mid/top end motor.
189 E
132 T
BD was low but can't remember what it was.

fulltiltrider I know you would not like a motor like this being the BD was low, but this motor runs great for the rider (friend) and has an old school FMF gold series pipe.

Bottom line....Whatever works for ya.

haha I would consider myself a beginer with a chisel and hammer compared to Arlen. If I knew all the tricks he does I probably could get those kind of numbers to work real well lol. Porting for low end and porting for top end is like comparing apples to oranges though. Low end stuff is all about the aim of the fuel charge to keep exhaust gasses out of the incomming charge, scavenging the cylinder is key, top end you dont worry about that so much. You are just trying to fill the cylinder with the most fuel and air as you can. Blowdown on the engine you are talking about is 30.5 by the way, and those old school h-49 pipes are supposed to be kept secret lol, they run real good. I just cant seem to get a cylinder to run real hard with anything lower than 33* BD.

[fulltiltrider]

Originally posted by rsss396


My cr500 trx is 196E - 124T on alky

I bet that baby rips your arms off lol. My zilla has a cpi oof that is designed for 200* on alky or else I probably wouldnt have it that high. Of course the width of my exhaust port is kinda scary at 75% of bore. I'll see how long my piston will hold together lol.

[rsss396]

The bike is still a work in progress been struggling with a few problems but its starting to come together.

I removed the bridge last year on another cylinder and it was very wide, it would defenately need new a piston every year.
I was not at all impressed with the differance of not having a bridge.

[fulltiltrider]

Originally posted by rsss396
The bike is still a work in progress been struggling with a few problems but its starting to come together.

I removed the bridge last year on another cylinder and it was very wide, it would defenately need new a piston every year.
I was not at all impressed with the differance of not having a bridge.

If I had the cash to get some custom pistons made, I would add a bridge to mine resleeve it and take it out to 100-110% of bore. You know how the saying goes, he who has the most cash.....lol

[rsss396]

I would add a bridge if not 2 on my intake side, with the 6mm stroke. The intake side of the piston is showing the most wear.
cr500 intakes look exactly like 86 250r cylinders

To bad mine has a brand new aluminum sleeve with nicasil, guess I will wait another season or 2 and do it.

[fulltiltrider]

Originally posted by rsss396


To bad mine has a brand new aluminum sleeve with nicasil, guess I will wait another season or 2 and do it.

Nice, I want to do that with my r when I get set on where I want the porting for my 310r setup. I'm torn on selling my current cylinder seeing it is a pv and was ported by Neil. Its my woods machine at the moment but its getting harder to find people to ride with anymore. Those 4 pokes dont like riding with a 23yr old machine that smokes the crap out of em lol. I'll probably sell it and pick up one of esr's new castings for a drag setup with a bridged ex.

[rsss396]

hoping my nefew gets one of the new esr cylinders, curious to see how they look compared to the old cylinders.

[hondamancbr03]

Originally posted by rsss396
hoping my nefew gets one of the new esr cylinders, curious to see how they look compared to the old cylinders.

Is ESR still using the Pro-X style cylinder? Or do they cast their own now?

[rsss396]

they have somebodyelse making them now and the price even dropped, hopefully the quality has not followed the price!

[hondamancbr03]

You know the old saying......You get what you pay for!

I have the Pro-X cylinder that was made by the same foundry that makes the CPI's.....Atleast from what i've been told. Very happy with the casting and quality.