Cam Options for a 1982 M10 E21 motor?

[winmag4582001]

My son pulled the head on his motor and I figured while its out, we'll look at a cam regrind for it.
What are the common grinds for a cam that's running stock ignition and k-jet?
Looking for the maximum cam for a stock motor. Not interested in changing pistons or upgrading the injection/ignition.
Who does a good grind with a reasonable turn around time?
What head gasket is good for these motors?

Thanks in advance!

[autox320]

My son pulled the head on his motor and I figured while its out, we'll look at a cam regrind for it.
What are the common grinds for a cam that's running stock ignition and k-jet?
Looking for the maximum cam for a stock motor. Not interested in changing pistons or upgrading the injection/ignition.
Who does a good grind with a reasonable turn around time?
What head gasket is good for these motors?

Thanks in advance!

I'm gonna sound like Mr. repeat . My favorite cam for stock motor was the racetep's ITB Stealth Cheater Grind for IT Racing. Stock Lift. 286 duration. Works with stock springs, K-jet. Works great out of the box. Even better on a carb setup. It works well with k-jet due to stock lift. I use VR (victor reinz)gaskets without issues. Elring is another good one.

https://www.racetep.com/automaker/bm...camshafts.html

[winmag4582001]

I'm gonna sound like Mr. repeat . My favorite cam for stock motor was the racetep's ITB Stealth Cheater Grind for IT Racing. Stock Lift. 286 duration. Works with stock springs, K-jet. Works great out of the box. Even better on a carb setup. It works well with k-jet due to stock lift. I use VR (victor reinz)gaskets without issues. Elring is another good one.

https://www.racetep.com/automaker/bm...camshafts.html

Is there a good difference in "feel" of the motor? Better launch or better mid range pull?
Thanks!

[autox320]

Is there a good difference in "feel" of the motor? Better launch or better mid range pull?
Thanks!

These are 4pots so not much in the launch or pull department unless up displacement. I'd say kjet with that IT cheat cam it could drive like stock never knowing it had a cam. Just a bit healthier midrange and when stayed on the go pedal was more zing at the top where it was really most noticeable.

If want more low end and midrange with it I'd adjust rockers to .003" instead of the noisy and lagging .007" factory gaps. That's just me but it does make a difference if trying to eek out gains from a simple valve adjustment.

Autocrossed and daily drove with the 286 cheater for years. Went even better with a carb setup later.

[320iAman]

Bone Stock is 264 degree-cam duration or crank shaft rotation with kick in the mid range, I doubt this would change much. Better launch is done thru the differential, higher numbers faster launch-higher top end rpm,lower numbers slower launch and lower top end rpm for a given mph.. Extreme example is circa late 60's-early 70's Chevelle SS with 427 twin 4 bbls with positive traction, with 4.11 rear end launch is very good with 4.56 rear end launch is outstanding, The SS 427 I seen a couple of these--factory special orders--money to burn and seen there burnouts-smoke shows -ect. no mention of these is found in wiki--writer of this article-missed this,,SS 454, I rode in this one.. ~ 10K from the factory first year--fast is an understatement. These were sweet rides yet could not compare to my Cousins 50's Chevy, 409-twin 4's ,B & M Hydro Transmission, traction bars and so forth, need a blank phone book to list the top end parts put in this one, even the paint was aerodynamic.. The ignition coil had some much juice in it that running the tachometer from the coil was impossible as too the massive jumps from the pulse train until he put in a capacitor the size of a D cell battery--then all good, 100% American made, He started working in the automotive business at 16 yo working in a Cam Company down the street--They got the blank Cam and ground them to fit nearly any application--update on Cam grinding is using a Cabinet with the prototype hand ground in one cabinet and blanks in other cabinets ground to fit the prototype by tracer arms connected to grinding apparatus to match the prototype,, I seen this first hand in Michigan,, an older gentlemen I met and was there when GM from Detroit showed up with there checkbook to make him an offer--he stayed on as President and he made Cams for all the GM cars. I needed a cam that was nla--he made it for me .. I know two people who made it too Overall Floor Shift Manager at a GM Plant and had 3 shifts of employees to direct around so the new cars kept rolling out the door--last Door CARB and EPA officials to due there due diligence pass off too the dealerships here and there in these United States,, no pass rework..

Randy

[wally509]

...

If want more low end and midrange with it I'd adjust rockers to .003" instead of the noisy and lagging .007" factory gaps. That's just me but it does make a difference if trying to eek out gains from a simple valve adjustment. ...
.

I think the opposite is true, at least it was on my car. Looser valves make more low end, tighter valve make more high end. .007" or .008" will give you sewing machine noise at warm idle however.

[autox320]

I think the opposite is true, at least it was on my car. Looser valves make more low end, tighter valve make more high end. .007" or .008" will give you sewing machine noise at warm idle however.

I've always had more response with tighter valve lash; reason is rocker(or bucket if direct) in this case follows the cam profile closer. Think like measuring a cam profile without lash vs with lash.

Some caution cause if not sure there are downsides. Could burn an exhaust valve not staying on the seat long enough over time. Needs the seat contact to transfer heat. Honestly like the OEM sodium filled valves better than aftermarket. Which if think about that means the valve is indeed off the seat more.

Decreases piston to valve clearance when critical measurements. In the M10's case takes a pretty big cam or wild cam timing to do that. But if was close and then tighten up the lash means your even closer at TDC. Chance of over rev can happen easier(closer at TDC), valve float putting more demand on the spring.

Pluses outweigh the negatives IMO; been running .003 since I can remember on an M10.

[wally509]

Okay, well, sounds like we can agree on tighter valves = slightly more lift and duration, looser valves = slightly less lift and duration? Hopefully that's the case since the opposite will be nearly impossible to argue a case for. I suggest the OP try this then:

1. Go to one of the larger cam manufacturers website that has a lot of cams for a lot of different engines, like Isky. Pick an engine, doesn't really matter which one, and look at the cams. Look at a low end or "torquer" cam, write down the lift and duration numbers (pay close attention to the duration number). Look at a high end (high RPM) cam for that same engine, write down the lift and duration numbers (pay close attention to the duration number). Do this for a few engines. Notice the trend in that duration number. Re-read the above statement.

and/or

2. Set the valves tight, drive the car and see how it feels. Let the engine completely cool. Set the valves to the loose end of the spec. Drive the car and see how it feels.

[winmag4582001]

OK. Last questions... LOL
VR head gasket: Do you use any copper coat on it? In the past working with Chevy's, I always sprayed a thin coat on the head gaskets that went between an aluminum head and iron block.
Head Bolt Torque: I've seen a few different specs on line. What is the rule for these little motors?

Thanks Again for all your help guys!

[autox320]

OK. Last questions... LOL
VR head gasket: Do you use any copper coat on it? In the past working with Chevy's, I always sprayed a thin coat on the head gaskets that went between an aluminum head and iron block.
Head Bolt Torque: I've seen a few different specs on line. What is the rule for these little motors?

Thanks Again for all your help guys!

updated torque spec is; 44 ft-lb, wait 15min, +33deg angle, run engine, then anytime cold or hot after engine temp reached +25deg angle in sequence

best to use a new set of head bolts as they have changed



I don't use copper spray, but loctite 99ma to ensure a good seal for everything. Heavy even coat both sides.

[winmag4582001]

Awesome! Thank you!
Do you not use the copper spray out of preference or do the German style gaskets and motors prefer the LocTite?