Noob Move, broke my reground S52 intake cam

[BenM]

Accidentally broke my reground (to Sunbelt Sport Specs) S52 intake cam in half last night whilist trying to install in my M52 swapped 318ti. The worst part is I mistook it for the regular S52 intake cam that were supposed to go in. Cam specs were 284 duration with .418 lift, compared to stock which is 252 duration with .401 lift.

Now I have to find another S52 intake cam and have it reground. Anyone have a spare one laying around?

[broach328]

dang, did you tighten it unevenly? and what is the cost on average to have them reground like that?

[BenM]

dang, did you tighten it unevenly? and what is the cost on average to have them reground like that?

American custom cam quoted me $100 for just a reground intake cam, so that's good. The problem is finding just an S50/52 Intake Cam, as they seem to be sold in pairs haha.

I broke it by thinking I could install it without rotating the cam (cyl. 3 lobes have pressure on lifters/valves at TDC). So I just loosened up everything accept the #4 bearing cap and the M52 intake cam came out great. Thought I could put the S52 cam in the same way, but bad idea. Upon reinstallation the cyl. 3 lobes wouldn't stay pointing down and my hamfisted ass accidentally bumped the cam from the front and it broke right in 2 pieces.

I think the major problem was not moving the cam so Cyl. 1 lobes were pointed down, so even when i tightened it evenly there was too much pressure in the middle of the cam.

[broach328]

yeah that sucks man I wish I had a cam for ya. and yeah not too many people sell them individually, except pelican parts but they are 1049.50 each :p

About rotating the camshaft, the most aggressive cams I have installed are m42 cams but I can still relate to your problem. only question is, if you rotated the cam until cyl1 lobes are down, youd have to be very careful about also rotating the crank. For some insurance, when I do it I back the crank up about 45-90 degrees where no pistons are at TDC then after cams are installed and secure at tdc, I rotate crank back to TDC and reinstall sprockets.

[M-technik-3]

Arg that is why I tried to buy that crazy cam tool a few months back for my Schricks. Sorry to hear your pain Ben.

On a side note I had a parts car lined up for lemons for the 5 speed swap. Guy has flaked on me and doesn't return calls. M42 coming out and M50/5speed going in since I don't have time Now.

[nrubenstein]

Did they promise that you will actually be able to use the cams? I have a set of regrinds and they were cut to too small a base circle with stock lifters. (Much to the dismay of the guy I sold them to. Obviously I took them back.)

But hey, if you want to experiment, I'll make you a deal on my set.

[BenM]

yeah that sucks man I wish I had a cam for ya. and yeah not too many people sell them individually, except pelican parts but they are 1049.50 each :p

About rotating the camshaft, the most aggressive cams I have installed are m42 cams but I can still relate to your problem. only question is, if you rotated the cam until cyl1 lobes are down, youd have to be very careful about also rotating the crank. For some insurance, when I do it I back the crank up about 45-90 degrees where no pistons are at TDC then after cams are installed and secure at tdc, I rotate crank back to TDC and reinstall sprockets.

$1K is crazy for just one cam. Bavarian recycling has an exhaust cam for $360, but no intake cams...

Yup, thats the method I'm going to shoot for now. Rotate the crank CCW 45-90deg which drops the #1 piston down and out of the way.

Arg that is why I tried to buy that crazy cam tool a few months back for my Schricks. Sorry to hear your pain Ben.

On a side note I had a parts car lined up for lemons for the 5 speed swap. Guy has flaked on me and doesn't return calls. M42 coming out and M50/5speed going in since I don't have time Now.

Damn that sucks about the car. I do have some spare Getrag 250 linkage stuff if you want it.

It's kind a bummer about the cams, but I should have it done no problem.

Did they promise that you will actually be able to use the cams? I have a set of regrinds and they were cut to too small a base circle with stock lifters. (Much to the dismay of the guy I sold them to. Obviously I took them back.)

But hey, if you want to experiment, I'll make you a deal on my set.

They didn't promise anything, but I know it's the same grind MR.325 used on his S50E30 a few years back. His car made 253whp w/ stock valvetrain stuff and a tune. Slightly less aggressive then what I had (280 duration, .415 lift), but the difference is negligible and will probably be a little safer.

I'm interested, what kind of specs? I'm guessing hydraulic lifters wouldn't adjust properly for the more aggressive ramp angle? Maybe they could be run with new lifters and stiffer springs... I'll shoot you a PM.

[Mr.SWISS]

yeah that sucks man I wish I had a cam for ya. and yeah not too many people sell them individually, except pelican parts but they are 1049.50 each :p

About rotating the camshaft, the most aggressive cams I have installed are m42 cams but I can still relate to your problem. only question is, if you rotated the cam until cyl1 lobes are down, youd have to be very careful about also rotating the crank. For some insurance, when I do it I back the crank up about 45-90 degrees where no pistons are at TDC then after cams are installed and secure at tdc, I rotate crank back to TDC and reinstall sprockets.

I do that on head jobs to avoid nicking a valve when I set it down.

Ideally the best way to R&R cams on a 24V is to lock the valves open then install then release valves. Never broke one this way, but it sure takes a lot longer than risking it.

[broach328]

I do that on head jobs to avoid nicking a valve when I set it down.

Ideally the best way to R&R cams on a 24V is to lock the valves open then install then release valves. Never broke one this way, but it sure takes a lot longer than risking it.

Yeah I never forked up the doh for the BMW torx socket that fits by the cam tray so I have to remove cams+trays to pull the head :)

About locking the valves. Def the best way and when dealing with parts I cant afford to replace, taking the long way is the only way for me at least. haha

[Wanganstyle]

Buy the proper e torx tool. $15 amazon prime

Sent from my GT-N7100 using Tapatalk 2

[ForcedFirebird]

I just ground down a regular e-torx socket to fit in.

Not such a noob move to break a cam, really. The local head rebuilding shops have done it - the reason we disassemble them in-house and just have the machine work done.

[broach328]

If I ever pull the head, its getting rebuilt so the cams have to come out anyways but I guess doing it off the motor would be more ergonomic and no risk of damaging valves. Plus its really not ideal torquing a head down using extensions and shit. Especially using the torque angle gauge. Some of you might have the fancy wrenches though haha

[DesertBMW]

Why do you need S52 cams to send for regrinding? You can get cheap M52 cams and get them regund to specs, they weld on material on them and gind them to specs you want.

[BenM]

Because I don't want to weld them. They are already hard and brittle, welding we weaken them even more and make them more prone to breaking. Most reputable shops won't weld them because of this.

I could regrind a set of m52 cams ground to s52 specs.

[Mr.SWISS]

If I ever pull the head, its getting rebuilt so the cams have to come out anyways but I guess doing it off the motor would be more ergonomic and no risk of damaging valves. Plus its really not ideal torquing a head down using extensions and shit. Especially using the torque angle gauge. Some of you might have the fancy wrenches though haha

The "fancy" e torx socket was like $25 from ZDmak but I use a snap on socket for my ARP's and an extension.