CR500: What engine mods to do?

glen howell · Post by **glen howell** » January 26th, 2010, 3:09 am

If it did it before then that should tell you someone was working on the squish after me or before you,He coudn't make it work or one of his montana engine people got there before you because I don't change the squish I only polish,I do tho mill the heads May'be that's why you got it so cheep,I'm sorry that I re-milled the head another15 thousands when you sent it to me now,But it was 12 thousands off.

britincali · Post by **britincali** » January 26th, 2010, 3:11 am

glen howell · Post by **glen howell** » January 26th, 2010, 3:15 am

Post by **AlisoBob** » January 26th, 2010, 4:05 am

MICK wrote:
ellett wrote:Ok, everything you want to know is in these posts:

Banned Encyclopedia of Horsepower
Ellet you have a son-of-a-bitchin' sense of humor

I know its only January, but that maybe the "Post of the Year" right there.....

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 6:16 am

dooing the decompressors have shown me alot of things about the heads:

-the wide ratio trans bikes have a wider squish with a narrow, taller pocket
-the close ratio trans bikes have a narrow squish with a wider, shallow pocket
-dont ever trust a casting to be true, never have i seen a chamber thats in the center, and theres no pattern to which way off they are. The first 2 i did for myself were a great example, the '88 head in the lathe was on center, the '01 head was off .015 or more. I have made a fixture that goes in my digital mill to find center, and level the head to either the squish or the current face, depending on what i'm dooing, a boring head will then cut it correct.
-i've had heads that have the chamber in them on an angle, heads that have the water jacket sunk down like a giant thumb shoved down on it (twice, one was new in the box)
-i know guys that run the cuts, some guys like it, some guys dont. EX: Seanmx57 has 2 heads done under the same theory by different guys, says one is forsure not as good as the other.
-If the chamber should have been different then theres no reason the guys that made the coolhead went thru all the work to come up with a profile almost exactly the same as the close ratio factory head in there 63cc dome
- the piston is a dome, the chamber should be a dome aswell. the factory head is about .005" more room at the pocket side of the squish than the outer edge so that it creates a high velocity shot of heat that ignites the fuel instead of waiting for the spark to get there, calming down detonation, btw: squish is not effective on anything with more than .065" of room
-some guys stand the plug strait up, wtf! the plug is there to blow the heat at the intake side of the piston, making the fuel think its a longer stroke and keeping the exhasut side cooler. if anything we should move the plug closer to the intake and add a wider squish over the exh.
-some guys run the coolhead and clock the head to where the plug fits the chassis best

.
-polish the shit out of the squish, (glen you have way more patience than i) and machine the head to achieve the right squish for your fuel, then ride it.

thats it for my morning rant

seanmx57 · Post by **seanmx57** » January 26th, 2010, 7:59 am

Roostius_Maximus wrote:dooing the decompressors have shown me alot of things about the heads:

-i know guys that run the cuts, some guys like it, some guys dont. EX: Seanmx57 has 2 heads done under the same theory by different guys, says one is forsure not as good as the other.

thats it for my morning rant

Please explain.

I've run a stock head (2000), the same modded for a 91mm piston, the same head set up for the big piston with your decompressor. I also ran one that I think was a 92 head while you were working on the 2000 head.

blownbillybob · Post by **blownbillybob** » January 26th, 2010, 8:06 am

[quote="Roostius_Maximus"]

-the wide ratio trans bikes have a wider squish with a narrow, taller pocket
-the close ratio trans bikes have a narrow squish with a wider, shallow pocket

i have noticed the exact same thing with the heads i thought a first the early head had a lower comp. ratio then the later till i cc'ed them, they were only 1cc difference i think i rechecked it like 3 times cause it was like 1am and was dead tired,i couldnt see the diff. at first till i measured the depth of the plug. BINGO

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 8:07 am

sean, for some reason i thought that head you ran as backup(1992) had the other angle cut aswell.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 8:11 am

It needs more squish cuz under more load it will ping easier

blownbillybob · Post by **blownbillybob** » January 26th, 2010, 8:17 am

i think 89 was the year they changed heads cause i have a 89 & 90 and they are diff.

so your 90s and later should be the same

i dont know if roostius has that in his cross over page he might have to do a update on the heads

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 8:30 am

i havent drawn up anything on it, i have a couple of modified heads here and only 1 narrow squish

going to try and get all the casting #s wrote down for which are which, actually its easy to tell what chamber you have by looking at the spark plug casting on top, the wide pocket has the plug mounted lower

seanmx57 · Post by **seanmx57** » January 26th, 2010, 8:35 am

Nope stock head, I was worried about problems with a 90.5 piston but everything looked good when it came apart.

So which heads are the good ones for MX, the ones off the close ratio motors?

blownbillybob · Post by **blownbillybob** » January 26th, 2010, 8:40 am

i thought the plug was in the same pos. but the chamber was lower - higher, on mine you can see the diff at the bottom of the plug threads????

will have to double check it tonight

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 9:14 am

a little early with this, but i have a few heads here to check against
i'm not saying this is the way it is, but it sure seems like it.

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 26th, 2010, 9:18 am

54mm wide pocket or 57.75mm
i'll get some more realistic specs up

100hp honda · Post by **100hp honda** » January 26th, 2010, 7:46 pm

glen howell wrote:If it did it before then that should tell you someone was working on the squish after me or before you,He coudn't make it work or one of his montana engine people got there before you because I don't change the squish I only polish,I do tho mill the heads May'be that's why you got it so cheep,I'm sorry that I re-milled the head another15 thousands when you sent it to me now,But it was 12 thousands off.

i sent the head to brit in the exact condition i got it in, i didnt touch it and neither did anyone in montana. you have to keep a good image for your "fans", so i can understand your relentless pursuit to push the blame onto me and brit for the screw up. as for the engine not being a "full" race, i gave brit the jug, head and piston....... the stator that you had rewound to have 10000 mega volts i gave it to another guy, my oplogies but i didnt know the full race was really only a "half" race without it

, and the cdi box that you took apart to supposedly remove the "rev limiter" i gave it to another guy also, my apologies again. so without the stator and cdi i guess brit only has a gss "qaurter" race engine ? is that what your saying ?

asteroid500 · Post by **asteroid500** » January 27th, 2010, 12:54 am

Guys-guys,
there is a solution

"TAKE A FUCKING HOSTAGE"

blownbillybob · Post by **blownbillybob** » January 27th, 2010, 6:13 am

Roostius_Maximus wrote:a little early with this, but i have a few heads here to check against
i'm not saying this is the way it is, but it sure seems like it.

didnt have time to measure anything last night but took a quick look at em my 89 head the plug was a little bit lower on top and about a 1/8 thick from bottom of threads to top of comb. chamber. the 90 was a little higher on top with the comb. chamber coming right into the threads

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 27th, 2010, 6:43 am

if you are certain they are off those year of engines will you please mark the engine year and the casting #

blownbillybob · Post by **blownbillybob** » January 29th, 2010, 12:00 pm

part # on top of head

89 head # ML3N
90 head # ML3?
91 head # ML3R
94 head # ML3R
i dont have my 90 motor in front of me so i just want to make 100% sure of the last letter i will also check my 93 and see what it is

http://www.youtube.com/user/500bigbore · January 29th, 2010, 12:31 pm

you know what E # they are?

blownbillybob · Post by **blownbillybob** » January 29th, 2010, 12:55 pm

im banging my head on the keyboard

you got me whats a E #

im sure im going to feel stupid in a bit

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 29th, 2010, 1:00 pm

hahaha, sorry dude. I've seen the e2 be different than the e3 but have the same ml#
if that makes sense

blownbillybob · Post by **blownbillybob** » January 29th, 2010, 1:06 pm

kinda makes sense where did ya get the e2-e3 #s from

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 29th, 2010, 1:22 pm

i have a ml3r e-4 off a SH 2003 bike
i have a ml3r F-3 that came new in the box last week
a ml3n e-2 here for a decompressor 96-98 i think
a ml3n e-1 i got from sean that was sold on ebay so who knows
all are small pocket

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CR500: What engine mods to do?