S52 track motor refresh

[pshooter]

So after a full season on a new to me E36 M3 (OBD2) I've pretty much had do undo or redo everything that the previous owners had touched. Car is a champ now and handles well and is pretty quick.
Towards the end of the season the oil consumption picked up to where I thought it was excessive. The leak down numbers weren't promising with 2 holes in definite trouble. All past the rings.
Any way motor is out and parts are arriving daily.

It had CP 11-1 pistons but the bores had more taper than I would like to see and the 2 holes that were in trouble showed some out of round as well.

In will go 87mm JE 11.5-1 pistons. I picked up a torque plate and off to get honed and the deck kissed.

Bearings and all the other bits look very good but will get new bearings any way because its apart. (As an aside I've been running the S54 pump. End of session very low oil pressure lifters ticking etc.. All the journals, bearings look great.) Pump is at VAC getting modified because it's apart.

So I have Schrick 264/256 cams and the car makes good power. The midrange torque is impressive and very flat.
I'm thinking about the 270 schricks but haven't found any real impressions, dyno #s, etc.
looking for some real world impressions or suggestions, experience with other grinds.
I like the idea of staying hydraulic but could be swayed.
Have all the supporting mods, springs etc.

TIA
Shoe

PS Staying N/A so save your breath on FI

[aeronaut]

I mean if you're doing pistons, 270 shricks, hell yes!
(PS, I am not an engine builder, and have no experience with the 270s. lol)

[jonb94118]

Personally I would stick with the more mellow cams and focus on longevity/reliability. 10-15 more HP at the top end isn't going to give you much in terms of lap time - especially if you are not competing at the pointy end of a specific race class. Before I went s54, I had an s52 that made 265 rwhp using stock cams, s52 headers, OBD1 with standalone and JE 11.5:1 pistons running pump gas. Great combination, plenty of torque. Make sure when the rings are gapped, to gap them on the looser side to avoid them butting when the motor is hot/under extended load.

[GG///M3]

Personally I would stick with the more mellow cams and focus on longevity/reliability. 10-15 more HP at the top end isn't going to give you much in terms of lap time - especially if you are not competing at the pointy end of a specific race class. Before I went s54, I had an s52 that made 265 rwhp using stock cams, s52 headers, OBD1 with standalone and JE 11.5:1 pistons running pump gas. Great combination, plenty of torque. Make sure when the rings are gapped, to gap them on the looser side to avoid them butting when the motor is hot/under extended load.

That’s pretty impressive. Did you use stock rods?

[pbonsalb]

Why not? I ran a supercharged and then turbocharged S52 for years with aftermarket pistons and stock rods. It had originally been built as a stock compression track motor. I bought it after running out of fuel and ruining my original S52 with supercharger. I simply changed the gasket to a thicker one, sold the Sunbelt cams that were in it and swapped in my 264/256 Schricks, ran it supercharged and later ran it turbocharged.

I now have a fully built block. As I recall, the weight difference between stock and aftermarket rods was about 2 lbs total. I doubt most people would feel the extra 5 ounces per cylinder.

While I like the 264/256 Schricks because there is zero downside and some dynos have shown them to actually reduce the low end losses that come from running an M50 manifold in place of the S52 manifold, they add only about 10 rwhp peak power. They do extend the power band a bit, in terms of reducing the steepness of the dropoff in the last 500-1000 pm depending on what limiter you use. But more serious cams will add a lot more up top. A few have played with cam timing to reduce the low end loss, but I don't know much about that. One of our members, Someguy2800, knows a fair amount and even prints plastic timing blocks to make it easy to time to new specs (no degree wheel) if you or he knows a spec that works for the cams you are looking at. Go more radical on the cams and you might want to consider an aftermarket crank damper, aftermarket springs and retainers, and if you go hardcore, a solid lifter conversion (beware cams are designed for one or the other so spec your cams to your lifter type).

A full top end build with springs, retainers, cams and port work gains way more power than a full bottom end build, but costs as much or more.

[bimmerboy318]

“In stock” JE pistons have stock valve reliefs according to JE. When I heard this, my desire to upgrade from stock cams vanished, and project money was a bit tight. I stayed with 86.5mm pistons to allow use of the OEM gasket. But I started with an 86mm S50 so your 86.4mm S52 probably needed the 87. What ECU are you using? I also upgrade to Supertech valve springs for peace of mind. Hoping that rwhp will be over 240 without exhaust.

Knowing what I know now.... if I had to do it again. Things I’d consider changing from my S50 build.
M50 block bored/hone to 86.5
S52 crank and run 7200rpm
Custom S52 Wiesco or CP 11.5:1 CR with HUGE valve reliefs
Supertech Springs
Shcrick 276/270 cams
OBD1 standalone ECU

[aeronaut]

I'm starting to believe the valve-piston clearance issue of these engines is somewhat misunderstood.
More clearance is better in case of over-rev, but at some point, that's expensive insurance (combustion efficiency, etc.).
If I understand correctly, valve-piston clearance is at its tightest on these VANOS engines at mid-rpm levels.
Not to say a floating valve hitting metal won't hurt, but does that really happen on a healthy (rebuilt, or properly built) engine at 7400 or less rpm?

[pshooter]

I was already at 86.5 with the CP pistons so 87 was my option save for finding another block. But there is already a fair amount of work into this block (main studs and line bore). After weighing my options and cost I opted to go 87mm.
Already have springs, just picked up an ATI damper (Merry Xmas to me).

I had to swap heads due to some poor repair work and opted for one of the AMC head castings. A fair amount of port work was necessary to bring it to at least stock dimensions (mostly guide and bowl). I'm revisiting it again now that it's off and looking to get some flow bench time. It made good power so all in all good.

So it was mentioned a 10-15hp bump with the 276's. I haven't been able to find any data or first hand users to back that up. Also curious as to what the curve looks like. I also think I want to limit myself to 7200ish RPM to keep the crank happy.

I'm not too concerned with what goes on below 4K rpm but on the other end a cam that runs to 8200 and I'm shifting a thousand rpm sooner doesn't make sense either unless there's a good bump in the 4-7200 range.

[bimmerboy318]

You are correct aero. By huge reliefs I mean ones big enough where a Vanos shim would not be needed. The vanos shim would limit advance in the mid range where clearance is tightest. Piston to valve interference cannot be eliminated completed (I’ve been learned).

JE Part# 297182 Valve pocket information
Intake : 1.400 X -.120 deep pocket
Exhaust : 1.350 X -.020 deep pocket

These match stock per JE.

I’ve read the Shcrick 276/270 used with and without vanos shims with stock bottom ends. Not sure if they retard the cam timing, use shims, or happen to have enough space.

Stock cams 9.7/9.7mm lift. Shcrick 276/270 are 11.2/10.8mm. So maybe pockets that were 1mm or .040” deeper than stock? I’m sure cam duration would impact this as well.

[bimmerboy318]

Maybe look through this thread for graphs?

https://www.bimmerforums.com/forum/s...-270-cams-DYNO

[aeronaut]

You are correct aero. By huge reliefs I mean ones big enough where a Vanos shim would not be needed. The vanos shim would limit advance in the mid range where clearance is tightest. Piston to valve interference cannot be eliminated completed (I’ve been learned).

JE Part# 297182 Valve pocket information
Intake : 1.400 X -.120 deep pocket
Exhaust : 1.350 X -.020 deep pocket

These match stock per JE.

I’ve read the Shcrick 276/270 used with and without vanos shims with stock bottom ends. Not sure if they retard the cam timing, use shims, or happen to have enough space.

Stock cams 9.7/9.7mm lift. Shcrick 276/270 are 11.2/10.8mm. So maybe pockets that were 1mm or .040” deeper than stock? I’m sure cam duration would impact this as well.

Yes! When I was considering 276/270s, what I understood was, one needs to measure valve/piston clearance with these cams. With everything else OEM, some will pass, and some will not and a vanos shim will be needed.

[pshooter]

I find it interesting that the cam card info (duration @ lift) is not openly published for most of these cams.
In the V8 world duration @.050 lift and the Jap world duration @ 1mm lift are the real numbers and differ significantly from advertised durations.

[jonb94118]

That’s pretty impressive. Did you use stock rods?

I did use stock rods - I was trying to keep it simple. Everything balanced out pretty perfectly from the get go as well using the stock rods. Per the other questions on JE valve reliefs - I used off the shelf 87mm 11:5.1 and they are much deeper than stock. I can take a picture later if someone wants. You want the deeper pockets on a track/race motor - mis/bad shifts happen... As for the cams and 10-15 HP, just a guess. Maybe more, maybe less and of course it's going to depend on everything else going on with the motor. I was just saying to focus on area under the curve as opposed to peak. I have endless data on track showing different combinations of HP (running max tuned, detuned, s50, s52, s54) and all else equal, the higher peak numbers don't make that much of a difference (in time) over the course of a lap. For me, I don't see the value and would spend money/time elsewhere. Maybe just use what you have, but spend the money on the head/valvetrain/porting and you can always switch the cams out later if you want?

Fully agree with pbonalsb on the following:

"Go more radical on the cams and you might want to consider an aftermarket crank damper, aftermarket springs and retainers, and if you go hardcore, a solid lifter conversion (beware cams are designed for one or the other so spec your cams to your lifter type).

A full top end build with springs, retainers, cams and port work gains way more power than a full bottom end build, but costs as much or more."

[pbonsalb]

I was told by JE that the valve reliefs are bigger than stock. They certainly looked like it. I run the 9.0:1 JE 86.6mm.

For turbo use you can reduce the likelihood of valve piston contact by dropping CR through a spacer instead of through the piston. It’s not ideal for squish but I have not read that less than ideal squish causes any issues on these motors.

Stiffer valve springs are probably the best protection against piston to valve contact.

[GG///M3]

I did use stock rods - I was trying to keep it simple. Everything balanced out pretty perfectly from the get go as well using the stock rods. Per the other questions on JE valve reliefs - I used off the shelf 87mm 11:5.1 and they are much deeper than stock. I can take a picture later if someone wants. You want the deeper pockets on a track/race motor - mis/bad shifts happen... As for the cams and 10-15 HP, just a guess. Maybe more, maybe less and of course it's going to depend on everything else going on with the motor. I was just saying to focus on area under the curve as opposed to peak. I have endless data on track showing different combinations of HP (running max tuned, detuned, s50, s52, s54) and all else equal, the higher peak numbers don't make that much of a difference (in time) over the course of a lap. For me, I don't see the value and would spend money/time elsewhere. Maybe just use what you have, but spend the money on the head/valvetrain/porting and you can always switch the cams out later if you want?

Fully agree with pbonalsb on the following:

"Go more radical on the cams and you might want to consider an aftermarket crank damper, aftermarket springs and retainers, and if you go hardcore, a solid lifter conversion (beware cams are designed for one or the other so spec your cams to your lifter type).

A full top end build with springs, retainers, cams and port work gains way more power than a full bottom end build, but costs as much or more."

Good info. I’ve thought about doing a 12.1 high comp 87mm motor in the past. Not sure how that would fair with pump fuel, but it would be great if flex fuel would be doable on the stock ecu

[pshooter]

I'll certainly check valve to piston and piston to head during mock up assembly.
All the information I've gathered so far is with the cams at issue here there shouldn't be an issue.
I will find out what those clearances are.

This isn't an nth degree build by any stretch of the imagination. And that's the reasoning behind it. I log quite a few track miles in a season and while I want to make sure that I can get realistic power with the assembly of chosen components. I want to maintain season long reliability to focus on the chassis and driver.

Digging into the block is only to correct prior workmanship. I wasn't unhappy with the power it was making before.
I've done the E85 thing before with my Evo and the hassle with amount and availability isn't worth it to me.

[olemiss540]

Why not just slap an S54 in there? BMW already built the motor you are after and you could recoup a bit of coin parting out your motor....

[pshooter]

When and if the right opportunity presents itself I'd entertain a swap.
It's cheaper for me to play with the S52 for the time being.
And right now I'm having a blast wringing out the S52.

[bimmerboy318]

That info I shared was from a JE rep. When I get my short block... I’ll measure myself.

- - - Updated - - -

Yes, this. I’ll publish my line item by line item spend on my S50 when I get it back but think it’ll be thousands less than an S54 swap.

[pshooter]

That info I shared was from a JE rep. When I get my short block... I’ll measure myself.

- - - Updated - - -

Yes, this. I’ll publish my line item by line item spend on my S50 when I get it back but think it’ll be thousands less than an S54 swap.

I figured I'll be into the basic refresh for $2,000 ish upgrading cams is another 1500-2000

I figured a proper S54 swap would be at least 10K - 15K depending on the state of the donor motor. vanos, rod bearings, leakdown.

[pshooter]

So what are the sunbelt equivalents these days?
Did somebody buy and rebrand them ? Or they just shut the door? Good luck and search for used? Experiences with CAT or others ?

[olemiss540]

10k for an S54 swap?? Whaaaa?? Not on a racecar not needing creature comforts....

You will spend 2k on a basic bottom end refresh, 2k on larger cams plus whatever high end valves, springs, retainers, etc , already have 1500 in oiling upgrades (that you could resell).

I am going to guess an S54 with basic maintenance items addressed would be another 1500 and you would be hunting serious power with a powerplant that has advancements of another 8 or 9 years.

I am just jaded with the reliability of a "built" motor over a stock drivetrain. I am sure it will be a blast and good luck with the build!

[pshooter]

1
I am just jaded with the reliability of a "built" motor over a stock drivetrain. I am sure it will be a blast and good luck with the build!

Thank You.
I've gone down the "built" rabbit hole before a time or 6 or 7?
For me at this point the cost is an incremental upgrade on the S52. I think it will stay in realm of stock reliability. It's still pretty under stressed.
I'll keep my eyes open for an S54 or E46 wreck as always. I have a short attention span.

[ScotcH]

I am going to guess an S54 with basic maintenance items addressed would be another 1500

Where are you finding s54 for $1500???

[GG///M3]

Where are you finding s54 for $1500???

Yup. S54’s are 3-4,500 plus rod bearings, vanos, and valve adjustments.

Then swap items another 2kish, so it’s not a cheap swap.