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Preemptive Head Grinding For Larger Cams

ctnewman

By ctnewman,
in Engines & Forced Induction

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ctnewman Enthusiast

ctnewman

Posted
Posted (edited)

I am in the process of building an RB26 that sits in an 87 BMW 325IS. (http://onyxsyndicate.com/newman/e30gtr/e30gtr_00.html)

Right now the bottom end has been rebuilt w/

87mm Wiseco

Eagle Rods

New OEM Oil pump

Crank Collar

1.5mm restrictor

The top end is currently at the machine shop getting a valve job, as well as the following parts:

New valve seals

Exhaust valve guides

Ferrea springs/locators/retainers/locs

Now comes the problems, I'm essentially out of money to buy cams right now. :(

I was thinking of getting procams or something similar in the future. I know that I need to grind the head to do this, which requires the head to be off the block for cleaning purposes.

What I need to know, is what is the width of the lobe on most aftermarket cams, and is this something I can do without checking the head for clearance... I actually have done this before, about 4 years ago on my old 240 project, but I cannot remember how much I took off and where...

Can anyone help me out?

Edited by ctnewman
Sydneykid Grand Master

Sydneykid

Posted
Posted
What I need to know, is what is the width of the lobe on most aftermarket cams

The same as the standard cams

is this something I can do without checking the head for clearance

Yes

Cheers

Gary

Swiper the Fox Grand Master

Swiper the Fox

Posted
Posted (edited)

i suggest what he was probably trying to say is the height of the lobe. As it is this that fouls on the head when running larger aftermarket camshafts. Depending on base circle and cam lift the height will vary.

Gary is correct...the lobe width is the same...allow for end float when machining though.

Edited by DiRTgarage
STATUS Grand Master

STATUS

Posted
Posted

if you tell your machinist to factor in a max lift of 11mm (the largest ive seen is around 11.6mm but i highly doubt you'll need something that big) you will cover most brands and grinds except the all out drag gear without running into clearance issues. Base circle tend to be either 30 or 31mm

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