REBUILD: Done with the Twin Screw, Going TURBO!

[Tanks95]

Yea Right…Twin Screw For Life!!

About a year ago now, I was out toolin around and had a sudden loss of power under acceleration. Having been here before, I immediately lifted, shut the motor down, and coasted to a stop. After an under hood assessment, I called my wife and she brought my truck and we towed my toy home. I broke out the compression tester and checked all cylinders and it revealed the number six cylinder was not holding any pressure at all. My thoughts at the time were the MLS or possibly a bent valve. However, bent valve wasn’t too high on the list became it was nowhere near the top end of the RPM range when she gave way. Anyway, life continued to roll on and she feel to the bottom of the priority list, between moving, preparing to retire from the military, school, and our first grandson.

About 4 or five months ago I took the motor to John over at CES, because he is the closest reputable shop in this area (2 hours away). After a discussion with him I had a great feeling that he absolutely knew what he was doing. Well, well….to both our surprise, a few days later John called with a little uncertainty in his voice. He said after pulling the heads he seen something he had never seen before. BOTH cams were snapped clean in half at the same point. Hmmmmm. Yea, neither of us could really come up with any definite reason why.

So, to shorten this prologue up a little. I proceeded to scan the net for new (used) S52 cams and other parts that would be needed. In the end John and CES took care of all the head work, ARP head studs, cut rings, etc, etc, and another valve job while he was in there. I just got around to re installing it back in the car over the past few weeks.

Since HEAT is my number one enemy, here are the planned changes:

Kenne Bell Boost a Pump
Snow Performance Water meth
Race fuel, possibly T4 (why? Because that’s what I run in my race bike, so I always have it)
Real OEM fan


Thanks to John at CES! Professional, laid back, meticulous, affordable work! Treated my motor like it was his.

Thanks to Mike at TRM! Thank you for the advice, and talking me off the ledge!

Thanks to Thomas, for the advice!

Thanks to MilkT for the boost a pump!

Thanks to Josh, for an amazing KIT!

More to follow….

20140926_235753 by William Wallace, on Flickr

20141124_195658 by William Wallace, on Flickr

20141124_195649 by William Wallace, on Flickr

20141124_195710 by William Wallace, on Flickr

At CES
20141205_135151 by William Wallace, on Flickr

Oh WOW
what happened idk by William Wallace, on Flickr

guides leaking by William Wallace, on Flickr

wrapped in plastic (3) by William Wallace, on Flickr

wrapped in plastic (2) by William Wallace, on Flickr

hg-install1 by William Wallace, on Flickr

CUT Rings
hg-install3 by William Wallace, on Flickr
hg-install4 by William Wallace, on Flickr

hg-install7 by William Wallace, on Flickr

ww-vanoscams3 by William Wallace, on Flickr

ww-vanoscams4 by William Wallace, on Flickr

BACK HOME!

20150201_120540_HDR by William Wallace, on Flickr

20150206_194010 by William Wallace, on Flickr

Cherry Picker (1) by William Wallace, on Flickr

DSC_1614 by William Wallace, on Flickr

DSC_1618 by William Wallace, on Flickr

DSC_1624 by William Wallace, on Flickr

[GG///M3]

Glad to see you didn't give up for exhaust fed boosts.

Hi 5

[Butters Stoch]

How many TS miles do you have thus far. ?

[Tanks95]

20150522_081634 by William Wallace, on Flickr

20150525_100031 by William Wallace, on Flickr

20150525_104909 by William Wallace, on Flickr

BACK IN!

20150525_143148 by William Wallace, on Flickr

Folding option is great!

20150525_143235 by William Wallace, on Flickr

- - - Updated - - -

How many TS miles do you have thus far. ?

hmmm, id have to look back through my records. I've had it for years, but between deployments and it being a weekend driver only, i don't know right off hand.

[abradic]

WOW! I have never heard of cams snapping like that out of no where...I don't think I have seen a thread or post anywhere on here with that issue. I wonder if there was a bad batch during manufacturing with perhaps a stress of some sort in that area. Very strange. The motor was in good hands so it should be good to go now. I'm glad to see your thread title was a joke Your car is so bad ass and unique, I look forward to seeing her get back on the road again and breaking that 500 whp barrier.

[Butters Stoch]

I can only think they got cracked on install. Its the only think logical .but dunno.

[litemup]

I can only think they got cracked on install. Its the only think logical .but dunno.

if they were, then the chances of them both completely fracturing at the exact same time...

[Butters Stoch]

if they were, then the chances of them both completely fracturing at the exact same time...

Well, Tank stated that compression was bad for #6.
Looking at the picture of the cams, I don't know how cylinder #5 was any good.

[hobbit382]

Well, Tank stated that compression was bad for #6.
Looking at the picture of the cams, I don't know how cylinder #5 was any good.

still has 1 lobe to allow air in and out. You crank it long enough, do compression test without the throttle all the way down it might go unnoticed, especially if the next cylinder shows 0. I would think something had to happen for both to crack at the same time. Hopefully it's figured out before it happens again.

[Tanks95]

WOW! I have never heard of cams snapping like that out of no where...I don't think I have seen a thread or post anywhere on here with that issue. I wonder if there was a bad batch during manufacturing with perhaps a stress of some sort in that area. Very strange. The motor was in good hands so it should be good to go now. I'm glad to see your thread title was a joke Your car is so bad ass and unique, I look forward to seeing her get back on the road again and breaking that 500 whp barrier.

Thanks.

I can only think they got cracked on install. Its the only think logical .but dunno.

Yea, we thought of that, but it seems they would have gave way sooner.

if they were, then the chances of them both completely fracturing at the exact same time...

pretty high odds.

still has 1 lobe to allow air in and out. You crank it long enough, do compression test without the throttle all the way down it might go unnoticed, especially if the next cylinder shows 0. I would think something had to happen for both to crack at the same time. Hopefully it's figured out before it happens again.

Here is why it maintained pressure in number 5:

break by William Wallace, on Flickr

ww9 by William Wallace, on Flickr

ww8 by William Wallace, on Flickr

ww7 by William Wallace, on Flickr

ww6 by William Wallace, on Flickr

ww5 by William Wallace, on Flickr

ww3 by William Wallace, on Flickr

ww2 by William Wallace, on Flickr

[525fourthew1n]

Now THAT is something that I have never heard of. I've seen an M20 camshaft explode on a concrete floor....but that's a hell of a weak-point discovery.

I realize they're expensive, but given your platform, what are your thoughts on Schrick cams?

The photos of your findings are awesome--thanks for posting! Hope to see this car next time I'm in Charlotte.

[Tanks95]

Now THAT is something that I have never heard of. I've seen an M20 camshaft explode on a concrete floor....but that's a hell of a weak-point discovery.

I realize they're expensive, but given your platform, what are your thoughts on Schrick cams?

The photos of your findings are awesome--thanks for posting! Hope to see this car next time I'm in Charlotte.

Yes, very strange. i've never seen it either, but then again, im not in the car business. However, neither John nor Mike had never seen that either, and they are in the tuner business.

i have no real valid opinion, on Schrick cams, this was my first experience with them.

[wazzu70]

At first I was disappointed to see the thread title and you as the OP. I was quickly relieved though!!

Thats pretty crazy on the cams.

[dburt86]

Were the valves bent on 6?

[Tanks95]

Were the valves bent on 6?

none at all.

[hsvturbo]

It looks to me that:

The #7 exhaust (A7) cam cap broke, which then caused the cam to be unsupported which cause the cam to break.

the intake cam studs look to be pulled out from the head on E7 cam tray location, which again caused the cam shaft to be in supported. Actually, it looks like one stud was never screwed down fer enough to begins with.

Tough break OP. But I'm still looking for that turbo haha.

[Tanks95]

It looks to me that:

The #7 exhaust (A7) cam cap broke, which then caused the cam to be unsupported which cause the cam to break.

the intake cam studs look to be pulled out from the head on E7 cam tray location, which again caused the cam shaft to be in supported. Actually, it looks like one stud was never screwed down fer enough to begins with.

Tough break OP. But I'm still looking for that turbo haha.

Good assessment, and true. But, why failure at the same time?

Anyway, ive moved on....

as for the turbo, there seems to be a resurgence of turbo cars lately (+/- 5 years) from the big manufacturers. If i were 20 years younger, id say its "trending"

[hsvturbo]

So if the A7 cap broke, thus breaking the exhaust cam shaft, the the exhaust gases inside the chamber would be inside the cylinder when the intake valves started to open. In high pressure inside the chamber required extra forece from the camshaft which then pulled the studs on the intake cap, E7, which obviously broke the intake cam.

thats my theory.

[Jab31169]

dang....thats crazy! Have you talked to schrick?

I saw the title and was about to ask how much you wanted for the blower

No oil cooler?

[5mall5nail5]

^^^ I am with you, if the exhaust cam cap broke and the cam broke, then the exhaust valves for #6 wouldn't open, the compression in the cylinder means that the valves have to open against that highly pressurized cylinder and maybe that load was too high for the camshaft and it snapped the intake.

[SM3]

Looking good!!

[BadBoostedBmwM3]

Wow!

I thought you had schrick cams?

[flyfishvt]

OP just ruined my day. I came in here saying.....ohhhhh yea...gonna get me some twin screw today!!!! Ppfffftt

[milKt]

Welcome back Sir.
Again, congrats on NEARING your military retirement.
I hope your comrades give you a wonderful ceremony. (pauerful stuff there...very emotional.)
Thanks again for serving us...truly.

Now

as you already know,
William,

I broke an exhaust cam in my m50 Estate during a pull onto I95.
It broke in exactly the same spot as yours.
Similarly,
I had never seen or heard of ANYONE snapping a cam during a driver....only during an INSTALL.

We are cam twins...not to be confused with you know who.

It is possible I installed them incorrectly,
but it took two years for them to "react" to my install.
lol

Something to consider...


in addition to the posi- donuts on your front lawn.

[Tanks95]

dang....thats crazy! Have you talked to schrick?

I saw the title and was about to ask how much you wanted for the blower

No oil cooler?

No i haven't, dont plan to. Also, only one cam was schrick, classic TRM old school tactic.

^^^ I am with you, if the exhaust cam cap broke and the cam broke, then the exhaust valves for #6 wouldn't open, the compression in the cylinder means that the valves have to open against that highly pressurized cylinder and maybe that load was too high for the camshaft and it snapped the intake.

yup, makes sense.

Looking good!!

Thanks

Wow!

I thought you had schrick cams?

Just one.

OP just ruined my day. I came in here saying.....ohhhhh yea...gonna get me some twin screw today!!!! Ppfffftt

heh, heh, heh

Welcome back Sir.
Again, congrats on NEARING your military retirement.
I hope your comrades give you a wonderful ceremony. (pauerful stuff there...very emotional.)
Thanks again for serving us...truly.

Now

as you already know,
William,

I broke an exhaust cam in my m50 Estate during a pull onto I95.
It broke in exactly the same spot as yours.
Similarly,
I had never seen or heard of ANYONE snapping a cam during a driver....only during an INSTALL.

We are cam twins...not to be confused with you know who.

It is possible I installed them incorrectly,
but it took two years for them to "react" to my install.
lol

Something to consider...


in addition to the posi- donuts on your front lawn.

Thanks!

Yea, point taken. But....let's move on.

oh, by the way, an estate doesn't count as a real car, its in the same category as a minivan