quick shimming help please!!!

[donnybrasco24]

ok i dont know if it is me or what but this excel thing is a bit funky....

i have a measured clearance of

R-in, .002/.0508 with shim 175

L-in, .003/.0762 with shim 170

R-exh, .014/.3556 with shim 265

L-exh, .016/.4064 with shim 265

now i input these into this excel program off the sticky here and i get new shim sizes of

R-in, 174.9238

L-in 169.9492

R-exh 265.0756

L-exh 265.1264

.....thats so close to the shims in there now.... all are off by less then a tenth of a shim size....with the hot cam shims i bought go by 5's. 2.60,2.65.2.70,2.75

i mean this is my first shim job am i missing something here? ?

thnx all

[nate_powell]

use crfsonly valve shim calculator. you need to type it in thousanths, not mm example/ .006 and shims also go in thousanths

[donnybrasco24]

yea i got the calc from

https://www.thumpertalk.com/forum/showthread.php?t=344989

the sticky. is this the wrong one?

yea i used the inch to mm conversion,

i used the .0508..0762....etc in the excel.

[donnybrasco24]

anyone able to enter those clearances in the excel and get different answers. i cant see how but maybe i entered it in wrong

grrr.

[nate_powell]

i have no idea what u talkin about. crfs only is a good one and so is the manual in ur book..u can also do it in your head. you figure how many thousanths of clearance you need to gain and then subtract that amount from the shim thats in there to figure out what shim you need. then just covert back to metric

[donnybrasco24]

well when i put in these clearances and the currect shims in there the excel program says but in a shim XXX. which is only .1 MAX off from the current shims i have in there now. like current shim 170. it says use a new shim of like 169.7xx i think it was.*at work atm*

i figure i would try the excel seemed easyer i guess i did something wrong.

so for the equation in the book convert all to standard find new shim size and of course convert back to metric?

[emoney]

Example - R-in, .002/.0508 with shim 175

Your intake clearance should be .006". Here's an easy way to calculate the req'd shim size without fancy spreadsheets.

.006" - .002" = .004" difference.

.004" x 25.4mm (conversion to metric) = .1016mm, we'll call it .10mm

Since we need to loosen the clearance we need to reduce the shim size, in this case .10mm, soooo 1.75mm - .10mm = 1.65mm or a 165.

You should always measure the shims, because a 165 is usually not 1.65mm especially not HotCams shims, which I've seen measure as little as 1.62mm.

[wheelz]

Example - R-in, .002/.0508 with shim 175

Your intake clearance should be .006". Here's an easy way to calculate the req'd shim size without fancy spreadsheets.

.006" - .002" = .004" difference.

.004" x 25.4mm (conversion to metric) = .1016mm, we'll call it .10mm

Since we need to loosen the clearance we need to reduce the shim size, in this case .10mm, soooo 1.75mm - .10mm = 1.65mm or a 165.

You should always measure the shims, because a 165 is usually not 1.65mm especially not HotCams shims, which I've seen measure as little as 1.62mm.

One of the best explanations I have seen on here regarding shim sizes!

?

Thanks man!

[Throttlejockey]

Here's an even easier way than that.

Use this sheet and count up or down from the shim you have for each .001 you need to change the clearance.

The part #'s are for the 450.

14901-MBB-000 .0472in 1.20mm

14902-MBB-000 .0482in 1.225mm

14903-MBB-000 .0492in 1.25mm

14904-MBB-000 .0502in 1.275mm

14905-MBB-000 .0512in 1.30mm

14906-MBB-000 .0522in 1.325mm

14907-MBB-000 .0531in 1.35mm

14908-MBB-000 .0541in 1.375mm

14909-MBB-000 .0551in 1.40mm

14910-MBB-000 .0561in 1.425mm

14911-MBB-000 .0571in 1.45mm

14912-MBB-000 .0581in 1.475mm

14913-MBB-000 .0591in 1.50mm

14914-MBB-000 .0600in 1.525mm

14915-MBB-000 .0610in 1.55mm

14916-MBB-000 .0620in 1.575mm

14917-MBB-000 .0630in 1.60mm

14918-MBB-000 .0640in 1.625mm

14919-MBB-000 .0650in 1.65mm

14920-MBB-000 .0659in 1.675mm

14921-MBB-000 .0669in 1.70mm

14922-MBB-000 .0679in 1.725mm

14923-MBB-000 .0689in 1.75mm

14924-MBB-000 .0699in 1.775mm

14925-MBB-000 .0709in 1.80mm

14926-MBB-000 .0719in 1.825mm

14927-MBB-000 .0728in 1.85mm

14928-MBB-000 .0738in 1.875mm

14929-MBB-000 .0748in 1.90mm

14930-MBB-000 .0758in 1.925mm

14931-MBB-000 .0768in 1.95mm

14932-MBB-000 .0778in 1.975mm

14933-MBB-000 .0787in 2.00mm

14934-MBB-000 .0797in 2.025mm

14935-MBB-000 .0807in 2.05mm

14936-MBB-000 .0817in 2.075mm

14937-MBB-000 .0827in 2.10mm

14938-MBB-000 .0837in 2.125mm

14939-MBB-000 .0846in 2.15mm

14940-MBB-000 .0856in 2.175mm

14941-MBB-000 .0866in 2.20mm

14942-MBB-000 .0876in 2.225mm

14943-MBB-000 .0886in 2.25mm

14944-MBB-000 .0896in 2.275mm

14945-MBB-000 .0906in 2.30mm

14946-MBB-000 .0915in 2.325mm

14947-MBB-000 .0925in 2.35mm

14948-MBB-000 .0935in 2.375mm

14949-MBB-000 .0945in 2.40mm

14950-MBB-000 .0955in 2.425mm

14951-MBB-000 .0965in 2.45mm

14952-MEB-000 .0974in 2.475mm

14953-MEB-000 .0984in 2.50mm

14954-MEB-000 .0994in 2.525mm

14955-MEB-000 .1004in 2.55mm

14956-MEB-000 .1014in 2.575mm

14957-MEB-000 .1024in 2.60mm

14958-MEB-000 .1033in 2.625mm

14959-MEB-000 .1043in 2.65mm

14960-MEB-000 .1053in 2.675mm

14961-MEB-000 .1063in 2.70mm

14962-MEB-000 .1073in 2.725mm

14963-MEB-000 .1083in 2.75mm

14964-MEB-000 .1093in 2.775mm

14965-MEB-000 .1102in 2.80mm

14966-MEB-000 .1112in 2.825mm

14967-MEB-000 .1122in 2.85mm

14968-MEB-000 .1132in 2.875mm

14969-MEB-000 .1142in 2.90mm

14970-MEB-000 .1152in 2.925mm

14971-MEB-000 .1161in 2.95mm

14972-MEB-000 .1171in 2.975mm

14973-MEB-000 .1181in 3.00mm

These are all the valve shims available for the CRF. The shims are marked in mm but they are rounded to three digits: 1.825mm is acutally 182 on the shim and 1.875mm would be marked 188. As far as the measurements in inches, I carried them out four places. If I would have rounded them, you end up with two different shims with the same english measurement. Must be the shift between the two standards I guess. RR.

[donnybrasco24]

the more and more i hear about hot cam shims....they are not sounding that good......sigh..... especially with the sizes. the increments are not that small....is there a shim "kit" that i could buy for example like that table that i don't have to worry about not having a specific size? i know i read a post RHC started. something about the shim , i want to say tolerances to heat? someone said oem was the best there was another brand also in there better then hot cam. any recommendations?

oh thanks so much...i kinda got the idea with the book equation. i just figure i would use this excel... leaves no room for error. but that didn't work*either my end or the excel end*

?

much thanks !!!!!!!