I see a lot of people throwing cams into basically stock itr motors lately.....

It is a growing trend, and I have been guilty of it myself in the past/ present...

I have encouraged everyone who has asked my advice to get the motor clayed when they install cams. Recently two people I know have installed spec b's (one on a stock jdm itr motor, and the other on a built high compression b18c1). I know other people installing smaller cams such as skunk stage 1's without claying the motor as well.....

Now this is not much of an issue with the cams at 0,0 - but I don't see how these guys will reach the maximum motor's potential with such settings. My experience has led me to believe that no two motors are alike, no matter how identical the setups. I have also had good results on my old itr motor and spec b's with a high degree of advance on the intake cam and lots of retard on the exhaust cam. I have been called crazy, foolish, etc - but that's where the motor made power, so that's where I left it.

Now, in lieu of claying the motor..... Many claim that they don't know how to do it, and as such would have to send it to a pro to be taken care of. They claim that the labor is cost prohibitive. Agreed. I prefer to do as much as I can myself (time/ work permitting).

I have heard of people doing an interesting trick to get a rough idea of what the valve to piston clearances are... and this trick involves locking the motor in vtec, then advancing one cam at a time (one degree at a time). Then rotating the crank by hand to see if the piston hits the valve. If it hits, then you know that's bad. If it doesn't, then you still have some room to play with and can advance another degree and try again.....

Has anyone used this "ghetto" method?

My biggest concern when I first heard this was "won't you bend a valve if you do crank the piston into it - even by hand?" Apparently, the valves - even stock ones - are able to handle this without any negative impact. True?

Another concern is that although at low rpm hand crank speeds the valve won't hit the piston, at 9k or 10k there is a minute bit of rod stretch... especially for stock components... How many degrees is a safe buffer in such instances?

Thoughts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">Alternatives to claying the motor?</TD></TR></TABLE>
Prayer

 

I'd be more afraid of valve float than rod stretch, but either way, turning the crank by hand doesn't tell you how much clearance there is, just that the piston didn't happen to hit a valve.

I too like to do as much work as I can, but there are plenty of things I can't do myself, such as honing the block, and having those things done by someone else is the price I pay. The way I look at it, if you're going to spend the money on the expensive parts, you might as well spend the money on having the motor clayed. If you can't afford to do it all, you really can't afford to do any of it, IMO.

 

You bring the piston to TDC, with VTEC locked, you adjust your gear until the valves hits(touches) the top of the piston. This will be a rough approx. of the number of degrees you can move your gears until piston valve contact.

Also keep in mind Rod/piston stretch when the motor is hot, etc...

Best way is still by using Clay.