I'm all ears still thinking bout those megas sitting on the shelf with some larger valves!

 

I remember when we were talking about your build way back when. Do you still want to keep wicked low end? I don't see why they should hurt it at all. If you keep the ports/carb smallish, you will keep your low end for sure. I'd say you can pick up quite a bit all the way across the board.

Idiot, It won't work. Nobody else is doing it!!:lol This thread will be awesome. I will converse tonight.

What is this TRX450R.ORG??? :lol

 

Idiot, It won't work. Nobody else is doing it!!:lol This thread will be awesome. I will converse tonight.

 

I can't wait to see how this is going to turn out!

 

Sredrum's prices
Bored FCR's 41mm,41.5mm,42mm and 42.5mm 125.00 shipped

FCR bored to 43mm 200.00 shipped

and it go's up from there.

i would like to see some flow numbers .
i have Ron's flow numbers some were and i have 2 heads setting at a bench getting ready to flow .
i also have flow numbers from a stock head some were

 

Feel free to post em if you can find em. I might eventually have some numbers, but I don't know just how fast I can get my flow bench calibrated.

 

Chuck, bore your carb to a 44. You won't lose bottom. I know I didn't. This engine is quite big enough to take it. Also, I told you so on the cams. Bigger is better in these engines. Mine will pull to the 10,800rpm limit, but not real hard. Prolly to 10,500 pretty hard. I also had a small port job. It's not small anymore by any means. I wish I could send you my head do you flow it. Id be interested in seeing what it would do.

 

I'm going to try to find a Mikuni HSR 45. It's a bolt on, and leaves room to go bigger yet. The carb is meant for big v-twins. It's the newer bigger better version of the HS40 I used to run.

You can send me anything you want for a flow test. I kind of touched on it in my last post, but I don't know exactly when or if I will get it calibrated. I will be able to compare it to a stock head, or my stuff. I will be able to compare to stock and modified TRX450R heads too.

 

It depends on if I have time or not. I actually have another head on the way I could duplicate the port job and send it to you.

 

Works for me. I've got more projects going right now than I have time, but the flow bench is pretty much at the top of the list.

 

Now for the sake of discussion, I also believe I could also taper bore the FCR to 43mm and port to that size, and not lose a bit of useable power. Just pure gain on the high end.

i was thinking about this myself. i think it would be a very high strung combo, with a very powerful mid. perfect for race apps. or it could suck balls

i would like to see the calculator for sure.

 

i dont understand any of the numbers or half the lingo but i love these threads. especially when cfm and kfxguy get to going back and forth. hey Chuck, is there a book or site that i can read on to get up to speed on the basics of what your talking about? not necessarily that math book you speek of yet but something a little more basic about flow,porting, all that good stuff. im a self taught mechanic and this is a bit over my head but would like to learn more. thx and good luck

 

We don't really go back and forth I'd say. We are pretty much on the same page. He just likes math more than I do :lol. We don't try to disagree with each other either. We pretty much agree on the same things. Sometimes we just do a little different things to arrive at the same result. My hats off to chuck for sure. He's helped me and I'm grateful for it. We all just have our different ways and opinions on things.

 

flattracker i had a bunch of links that were great port theory reading, of course i lost them with my last computer.

ill see if i can find some again, its actually not as complicated as it seems.

 

The calculator turned out great. I literally had to teach myself to use excel while trying to make it. Thank you youtube! Dan has a copy of the document. The site wouldn't let me attach that type of file. I'm sure it's just a matter of time.

The formula goes like this

Port velocity in feet/sec = (Piston speed in feet per minute / 60) x (bore squared in inches / Port cross sectional area in inches)

The calculator will show the Port velocity at every 1000rpm increment from 1k-12k rpm. When you input the bore and stroke, it will give you the displacement and give you the mean piston speed in feet per minute. You will need to know the cross sectional area of the port, the bore and stroke, and it will do the rest. You can adjust the volumetric efficiency percentage also. For port cross section, you can use the carb size if you plan to match the porting to the carb size.

For a quick reference, the port area for the common carb sizes go as follows:

39mm = 1.851in^2
40mm = 1.94in^2
41mm = 2.045in^2
42mm = 2.137in^2
43mm = 2.249in^2
44mm = 2.356in^2
45mm = 2.46in^2

 

what RPM are you building your engine to peak at?

 

On my engine with a 45mm carb, I think the hp will peak around 9500-10k and peak tq would be around 7500

 

Here's some good links. Not all are quite on topic, but good reads none the less.

Motoman has an epic site to get you thinking right.
thanx

This one especially is good to learn engine dynamics.
Power News -- The 8 Phase Motor

This page is awesome for degreeing cams! Even has a calculator to help
Web Cam Inc. - Performance and Racing Camshafts

A good read about spark plug reading
sparkplugreading

Believe it or not, this comes in useful
The Physics Classroom Topics


I used to have more too

 

If only someone would've told me then that numbers are involved in racing...

someone really needs to bring this to the teachers attention, because i feel the same way.

 

It would have saved me a lot of trouble that's for sure! I have been around race cars and dirt bikes most of my life, and I always knew that it was something I would stay with. I had no idea there'd be so much math involved. So now, it's twice as hard to figure all this stuff out. I've been consulting with Ray a lot too with this stuff to make sure I'm not losing it :lol

not really say you guys disagree, just its an interesting conversation between the 2 of you. i think you guys really bring the best thinking caps out when in discusion. keep up the good work and talking (typing) and ill keep learning.

OOOOOOHHHHHHH!!!!! when my motor needs redone its gona be an experiment of these theories. ill start puting back the pennies!!! i want 60 horse and not a bad spot in the pull. from bottom to top

Some times it's those discussions that bring out the best realizations for me. I don't feel like I will ever be done learning about this stuff. I remember thinking a few years ago that I was really starting to get on top of what goes on in these engines, and I think I've learned twice as much since then as I knew at that time :lol

For 60hp without a flat spot, plan on building a big motor. Even at 490cc's it might be tough to reach that level without it being pretty revvy. High compression would really help. That's going to be my biggest enemy with my build. It's a pump gasser, and there's no high compression 470 pistons out there. I really want to get a batch of custom pistons, but I don't have the budget for it this year. I don't know just how much these crank cases are going to hold either. I already broke one @ 54hp. May have been a fluke, but I know Gust was breaking some back in the day too.

It will be interesting to see when you start putting all these theories to test when you finish the flow bench. I'm staying tuned for sure. The thing I love about modding the z is, its so much cheaper and easier than my car was. 7 less cylinders, 2 less cams, and 1 less head to deal with, lol.

That's an understatement! Dad and I are restoring his Olds Rallye 350 also, and I think we're going to build a 450 ish hp 362 SBO for it. I don't really know where it will land for power, but it should be above average for what it is. I will be doing some really extensive head work on that too. 8cyl stuff is sooo much more work. :icon_neutral:

 

thx for the sites chuck.

 

hey chuck or kfxguy or both, i dont want to highjack this thread so if you get a chance check out the engine charicteristics thread i made. have some questions that just came to mind

 

It will be interesting to see when you start putting all these theories to test when you finish the flow bench. I'm staying tuned for sure. The thing I love about modding the z is, its so much cheaper and easier than my car was. 7 less cylinders, 2 less cams, and 1 less head to deal with, lol.

 

Yes is there a (Fixing My Z for Dummies)?? I'm with you Flat..LOL

 

i wasnt really talking about fixing my z posts. just some engine dynamics like they are talking about.

 

Sorry , I should say modifying. I've only had my Z for about a month so I'm still very green in the gills(the dummy). I have read so many posts on here, kinda don't know where to begin,I see all this talk about cams,valves,carbs,etc. I think I'm kinda lost

 

just as zookie400 said dont get caught up in it. also i think i spent a whole year reading, reading and reading all the same stuff over again. did i mention reading????? ooohhh and i still go back and read most of the same stuff as well as the new. i think i can remember some of it word for word...lol. just keep at it, read and ask questions and the mods will start to be addicting...good luck

 

begin with FUN. its the most important part. dont get caught up in trying to be the fastest most powerful out there.

when you are ready to upgrade (or forced to because something broke...) this forum will show you the way!

 

cfm, where are you going to set rev limit?

i need to look, how much room is there for raising the port? not much if i recall. just wondering if there was room for it, i think it could be a big help.

 

cfm, where are you going to set rev limit?

i need to look, how much room is there for raising the port? not much if i recall. just wondering if there was room for it, i think it could be a big help.

Yeah, I just got to the shop for a little while tonight and got to looking things over. 44mm looks like the max at the intake port opening without adding material. The opening will be getting pretty thin even at that point. Also, there's not much room to take the port higher. It would get in trouble at the base of the intake valve spring seat. May have to widen the port more to avoid having to go higher or lower. Lower = bad anyways.

I'm going to keep my rev limit at 10,500. The mean piston speed is 4600ft/min. Beyond 5000ft/min is bad territory. I did already find an HSR45 used that a guy had in a rhino. If need be, I may machine an insert to bring the size down 1mm, or if I mount it a little further from the head, it may take advantage of a gradual taper.

A few questions:

Shaping the long turn radius to be more of a "D" shape. Leaving the height the same, just shaping the top of the turn to be flatter, or even shaping the whole port roof to be flatter? Or would this just create a turbulent area?

Leaving the port throat the same diameter on the valve side but tapering it to match the port opposite of the valve? like: \_/ Or would this be to direct at the back of the valve and decrease flow?

I love when people try to argue that one.... No matter what you do to either curve, they'll always meet there, i don't care if you have a 4000 rpm redline, if you extrapolate, it'll be at 5250!

You've got your D upside down. You want to widen and flatten the floor without making it any lower. Look at moto man's epoxy port for a good example. But like I just said up there^ there's not that much room for the port to get taller in this head. The D will need to be fairly wide.

A little \_/ to the seat is good. You've got to keep in mind that you're trying to make it flow around a valve.

Like this

!......!
\....../
!.....!
/____\​

I had to use dots for spaces or the site would take out the excess spaces.​

The valve seat area before and after the valve, are where the biggest flow improvments can be found. The more efficient you can make that, the better everything else works.

 

A few questions:

Shaping the long turn radius to be more of a "D" shape. Leaving the height the same, just shaping the top of the turn to be flatter, or even shaping the whole port roof to be flatter? Or would this just create a turbulent area?

Leaving the port throat the same diameter on the valve side but tapering it to match the port opposite of the valve? like: \_/ Or would this be to direct at the back of the valve and decrease flow?

 

I love when people try to argue that one.... No matter what you do to either curve, they'll always meet there, i don't care if you have a 4000 rpm redline, if you extrapolate, it'll be at 5250!

 

i would be sweet to get a blank of aluminum and start from scratch. write some G-code for a cnc high port 60hp Z head.

i too was thinking about a custom piston. i dont need 8 though, nor do i want to pay for that many.

 

stock ltz

lift-----int cfm-----ex cfm-----%
50-----26----------14----------53.8
100----49----------43----------87.75
150----73----------63----------86.3
200----97----------77----------79.38
250---114----------85----------74.5
300---127----------91----------71.6
350---133----------94----------70.6
400---133----------97----------72.9

 

i'm told these are Rons drz flow numbers
LIFT DRZ CFM CRF CFM
.050" 53.6 44.5
.100" 103.1 93.1
.150" 149.9 144.5
.200" 192.5 183.1
.250" 229.3 222.0
.300" 253.4 244.9
.350" 261.6 253.0
.400" 270.0 258.0

Thanks, how many inches of water for those tests?

OK so... you are looking to get 43mm carb and place it how far from the valve?


would you then further the taper out to the filter or just use a straight bore pipe?

you are right, there isnt much room to raise the port.

i traded powdercoating services for a botched Z head, the port work on the intake doesnt look bad and the chamber and seats are salvagable. cfm how much would you charge me to get flow numbers for it? there is no place affordable by me, and i just dont have the time or money to build my own flow bench at the moment, although when life slows down for me i definitely will be building one. its an extremely useful tool.

I can port to 44mm I THINK I have a spare head, and I think it's going to be the sacrificial piece. Then again, If I use the head I've been using, It would save me some work.

I'm thinking if I port to 44mm and put the carb just a little further back to try to continue the taper from within the port, I could run the 45mm carb without much issue. I've been brain storming some new intake ideas too. I've never been a fan of the big step from the carb size to the intake size either. It'd be nice to have one constant taper from the air filter to the choke point. Resonance tuning should have a stronger effect that way I think. I'm even thinking about adding a plenum to the end to see if I can take advantage of that to boost resonance also. I have way more ideas than I have time or money :lol I've already got $400ish invested into this flow bench. New vacuum motors are about $100 each. I have two so far. I plan to add another one or two for bigger projects.


Just send me the head with return shipping, and I will test it for you since I'm just getting everything up and running. You will need valves in it, and good seats though to be accurate. If it has valve or seat damage, it will show up big time in the results. I don't know just how exact the numbers will be either, at least at first. I'm going to try to get everything calibrated and figured out, but it's going to be a little overwhelming at first. I'd give it a couple weeks anyways.