Piston Slap - New Pistons Break-In Advice. - LotusTalk

good2go · 10-26-2009, 11:52 AM

My 05 Elise N/A engine (53K mi) was knocking recently. I took it to my regular mechanic shop in San Diego and was told that piston #1 was slapping - checked everything else still look good: the valves, connecting rods, cams, rockers...etc.

First heard of Piston Slap as I'm not mechanical savvy - researched online and learned a lot. Anyway, I got some new Mahle Pistons, stiffer MWR valve springs and titanium retainers from Monkey Wrench Racing. It is normal for have piston slap on engine at only 53K miles. I maybe redlined it only once or twice for a second or so! Only a few track days and regularly maintained the engine by a qualified shop/mechanic.

The engine is getting a valve job, cleaned and bored and the above new parts will be installed - new again, yeah!

Question: the Mahle pistons is 12.3:1, not same as the stock 11.5:1 - will there be any issue?
Mahle Piston Set - Toyota 2zz - 12.3:1 compression 82mm - MAH-21123820 van Mahle - Monkeywrench

The website advised that the pistons are a direct drop-in to an unmodified 2zz engine. Is it safe and should be ok?

Also as in term of break-in, my mechanic advised that he will put in non-synthetic oil (less slippery) for break-in period of about 1000 miles, and take it easy - basically same as new engine.

Anything else (different) I should or should not do during the break-in period for our high compression N/A 2zz engine? I've researched online about breaking it new pistons and engine. Thank you very much in advance for any advice/suggestions, folks.

I'm actually excited bout getting the "re-new" engine!

trav34 · 10-26-2009, 01:36 PM

Come on somebody, pipe up. I'd be interested to know if bumping the compression is ok on street gas and if it's ok with no tune.

kverges · 10-30-2009, 06:59 AM

I would not bump compression on pump gas, esp. since Cali fuel is 91, right?

Piston slap is an odd diagnosis and I'd like to know how it is diagnosed and cylinder 1. It is very hard to figure out what cylinder it is in and I am surprised to hear of it at 53K miles.

Also, PS is not usuallyharmful to perfromance or longevity of engine unless it is severe - I have seen lots of engineering mules with over 300K miles and piston slap (sound is more like a tick, actually)

If you are tearing into the engine, I'd go ahead and look at the bearigns and valvetrain to be sure they are not the culprit.

JLSELISE · 10-30-2009, 09:38 AM

+1--You will likely need to use race gas if compression is increased that much--not a good idea!
It could even be a really bad idea if the knock sensor cuts way back on timing, which translates into less power

.

MaineLotus · 10-30-2009, 10:23 AM

Quote:

Originally Posted by good2go

My 05 Elise N/A engine (53K mi) was knocking recently. I took it to my regular mechanic shop in San Diego and was told that piston #1 was slapping - checked everything else still look good: the valves, connecting rods, cams, rockers...etc.

First heard of Piston Slap as I'm not mechanical savvy - researched online and learned a lot. Anyway, I got some new Mahle Pistons, stiffer MWR valve springs and titanium retainers from Monkey Wrench Racing. It is normal for have piston slap on engine at only 53K miles. I maybe redlined it only once or twice for a second or so! Only a few track days and regularly maintained the engine by a qualified shop/mechanic.

The engine is getting a valve job, cleaned and bored and the above new parts will be installed - new again, yeah!

Question: the Mahle pistons is 12.3:1, not same as the stock 11.5:1 - will there be any issue?
Mahle Piston Set - Toyota 2zz - 12.3:1 compression 82mm - MAH-21123820 van Mahle - Monkeywrench

The website advised that the pistons are a direct drop-in to an unmodified 2zz engine. Is it safe and should be ok?

Also as in term of break-in, my mechanic advised that he will put in non-synthetic oil (less slippery) for break-in period of about 1000 miles, and take it easy - basically same as new engine.

Anything else (different) I should or should not do during the break-in period for our high compression N/A 2zz engine? I've researched online about breaking it new pistons and engine. Thank you very much in advance for any advice/suggestions, folks.

I'm actually excited bout getting the "re-new" engine!

53k miles sounds too soon to develop piston slap. If it truely has piston slap, that is usually developed when the bore is worn. If it is, then the block is ruined and you'd need to sleeve the block. You mentioned boring - that can't be done on the 2zz block - it has a special coating. You'd need to have the block machined to accept iron sleeves.

If you currently have Mahle pistons, you can have some slap before the engine is warmed up because the pistons are forged instead of cast (OEM).

Seb · 10-30-2009, 06:32 PM

I have broken in a few motors like this: Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

The engine in my car was broken in with this method and I now have 35k on it. Standard factory compression for my car is 181psi, and that's where I'm at still.

If you were going to build the motor, why not just get a lower compression ratio setup, and just buy the turbo kit that someone is selling on here? You could make a **** load of power.

good2go · 10-30-2009, 10:06 PM

Appreciate all the comments, advices, and suggestions - keep them coming. I'm learning here.

It's surprising to me also that a 2zz engine had a piston slap at only 53K miles. The ticking noises made me really nervous and uncomfortable. Thus, I might have jumped the gun too quickly and had them replaced. The mechanic took out the pistons, physically/visually checked it and measured the cylinder/pistons/parts and clearance and discovered that it was piston #1.

I thought about the low compression 9:1 pistons but I didn't want to take the turbo or supercharger route. However, I'm a little concern about the 12.3:1 Mahle piston's higher compression. If things don't work out - I'll get the 11.5:1 wiseco pistons which come with sleeve.

Tomorrow, I'll be picking up the car in SD - I'll try to take some photos and post my initial driving impressions on the reworked engine. It's point of no return now, so wish me luck. I'll also get some correct verbage from my mechanic - I'm not mechanically inclined and don't want to misword/misquote the problem and solution.

Am I the only person here getting piston slap with the 2zz engine?

Thanks for the break-in tip. I also researched online and found debates on hard break-in vs. easy break-in.

vyuen · 10-30-2009, 10:19 PM

You can shave down your Mahle pistons to meet the stock CR spec if you're concerned

Dragon · 10-31-2009, 12:45 AM

You can probably pick up a thicker head gasket to also drop the compression some.

MaineLotus · 10-31-2009, 02:37 AM

Quote:

Originally Posted by Dragon

You can probably pick up a thicker head gasket to also drop the compression some.

No!

trav34 · 10-31-2009, 05:16 AM

Quote:

Originally Posted by good2go

Appreciate all the comments, advices, and suggestions - keep them coming. I'm learning here.

It's surprising to me also that a 2zz engine had a piston slap at only 53K miles. The ticking noises made me really nervous and uncomfortable. Thus, I might have jumped the gun too quickly and had them replaced. The mechanic took out the pistons, physically/visually checked it and measured the cylinder/pistons/parts and clearance and discovered that it was piston #1.

I thought about the low compression 9:1 pistons but I didn't want to take the turbo or supercharger route. However, I'm a little concern about the 12.3:1 Mahle piston's higher compression. If things don't work out - I'll get the 11.5:1 wiseco pistons which come with sleeve.

Tomorrow, I'll be picking up the car in SD - I'll try to take some photos and post my initial driving impressions on the reworked engine. It's point of no return now, so wish me luck. I'll also get some correct verbage from my mechanic - I'm not mechanically inclined and don't want to misword/misquote the problem and solution.

Am I the only person here getting piston slap with the 2zz engine?

Thanks for the break-in tip. I also researched online and found debates on hard break-in vs. easy break-in.

I can't wait to hear how it works out for you. I'm leaning more towards building a more powerful N/A engine than going with a turbo or supercharger.

MaineLotus · 10-31-2009, 08:59 AM

Quote:

Originally Posted by Seb

just buy the turbo kit that someone is selling on here? You could make a **** load of power.

guntao · 10-31-2009, 01:28 PM

i am in the same kind of situation, my block will be sleeved with darton sleeves, but now i dont know if i should stay with the stock ratio (with Mahle or wiseco) or go with just a bit more compression (Mahle has 12.3 wiseco has 12.0) also should i go with a bigger bore size ?? will it need an ecu modification ?`???

MaineLotus · 10-31-2009, 01:34 PM

Quote:

Originally Posted by guntao

i am in the same kind of situation, my block will be sleeved with darton sleeves, but now i dont know if i should stay with the stock ratio (with Mahle or wiseco) or go with just a bit more compression (Mahle has 12.3 wiseco has 12.0) also should i go with a bigger bore size ?? will it need an ecu modification ?`???

Bigger bore is not possible, not enough material between cylinders. Tuning needed - yes.

Seb · 10-31-2009, 06:10 PM

Quote:

Originally Posted by MaineLotus

Don't reply with a freakin' smiley face.

Look, with a built bottom end, and a good tune, that car will make insane power. If you already have the motor apart then why the hell not?

There is some incredibly bad advice here though. DO NOT shave the pistons.

I think you'll be fine with the compression ratio you chose. If you're worried, just hook up a knock sensor to a light so you can monitor it. Light blinks = get out of the throttle.

Honestly if I was going to build my bottom end, I would just go 9:1 or 8.5:1 and turbo it. That's if you have the funds.

Dragon · 10-31-2009, 11:44 PM

Quote:

Originally Posted by MaineLotus

No!

Is there some specific issue with the 2zz that won't allow this or do they not sell them? I've used HKS 2.2mm head gaskets etc to drop compression on Honda engines for turbo charging with no issues and these head gaskets are considerably stronger than stock. It does however change cam timing a tiny bit.

good2go · 11-01-2009, 07:51 PM

Update: I was all excited planning to pick up my ride yesterday when my mechanic called me...the engine pings at idle with the 12.3:1 Mahle pistons installed - probably too high of a compression - NOT a drop-in as described on MWR website. I'll try to return them! The mechanic recommended me just get the oem stock pistons from Lotus!!!

Thought about Wiseco 11.25:1 pistons for 2ZZ-GE, closest to what we have without going over the stock compression...

Tomorrow, I'll just call a local Toyota dealership and get stock 2zz-ge Celica GTS 11.5:1 pistons and call it a day. Keep it simple! Much cheaper than from Lotus dealership.

The saga continues....damn, did I do the right thing or should I have ignored the piston slap and just drove it?....

Dragon · 11-02-2009, 01:06 AM

They have a Mahle 10.5:1 compression piston on their web site that would work well. There would be minimal power loss N/A with them and it would allow you to safely add a turbo or supercharger kit with a little extra boost in the future....

Mahle Piston Set - Toyota 2zz - 10.5:1 compression 82mm - MAH-21105820 van Mahle - Monkeywrench

good2go · 11-02-2009, 03:37 AM

Quote:

Originally Posted by Dragon

They have a Mahle 10.5:1 compression piston on their web site that would work well. There would be minimal power loss N/A with them and it would allow you to safely add a turbo or supercharger kit with a little extra boost in the future....

Mahle Piston Set - Toyota 2zz - 10.5:1 compression 82mm - MAH-21105820 van Mahle - Monkeywrench

Thanks, I'll look into it also - leave me an option down the road.

JLSELISE · 11-02-2009, 07:16 AM

Quote:

Originally Posted by good2go

Update: I was all excited planning to pick up my ride yesterday when my mechanic called me...the engine pings at idle with the 12.3:1 Mahle pistons installed - probably too high of a compression - NOT a drop-in as described on MWR website. I'll try to return them! The mechanic recommended me just get the oem stock pistons from Lotus!!!

Thought about Wiseco 11.25:1 pistons for 2ZZ-GE, closest to what we have without going over the stock compression...

Tomorrow, I'll just call a local Toyota dealership and get stock 2zz-ge Celica GTS 11.5:1 pistons and call it a day. Keep it simple! Much cheaper than from Lotus dealership.

The saga continues....damn, did I do the right thing or should I have ignored the piston slap and just drove it?....

Hate to say "I told you so", but the mechanic really should have known better in this case.

10-26-2009, 11:52 AM	#1 (permalink)
good2go Registered User Join Date: Mar 2007 Location: Downtown LB, California Posts: 498	Piston Slap - New Pistons Break-In Advice. My 05 Elise N/A engine (53K mi) was knocking recently. I took it to my regular mechanic shop in San Diego and was told that piston #1 was slapping - checked everything else still look good: the valves, connecting rods, cams, rockers...etc. First heard of Piston Slap as I'm not mechanical savvy - researched online and learned a lot. Anyway, I got some new Mahle Pistons, stiffer MWR valve springs and titanium retainers from Monkey Wrench Racing. It is normal for have piston slap on engine at only 53K miles. I maybe redlined it only once or twice for a second or so! Only a few track days and regularly maintained the engine by a qualified shop/mechanic. The engine is getting a valve job, cleaned and bored and the above new parts will be installed - new again, yeah! Question: the Mahle pistons is 12.3:1, not same as the stock 11.5:1 - will there be any issue? Mahle Piston Set - Toyota 2zz - 12.3:1 compression 82mm - MAH-21123820 van Mahle - Monkeywrench The website advised that the pistons are a direct drop-in to an unmodified 2zz engine. Is it safe and should be ok? Also as in term of break-in, my mechanic advised that he will put in non-synthetic oil (less slippery) for break-in period of about 1000 miles, and take it easy - basically same as new engine. Anything else (different) I should or should not do during the break-in period for our high compression N/A 2zz engine? I've researched online about breaking it new pistons and engine. Thank you very much in advance for any advice/suggestions, folks. I'm actually excited bout getting the "re-new" engine!

10-30-2009, 09:38 AM	#4 (permalink)
JLSELISE Registered User Join Date: Jun 2004 Location: Livermore, CA Posts: 489	+1--You will likely need to use race gas if compression is increased that much--not a good idea! It could even be a really bad idea if the knock sensor cuts way back on timing, which translates into less power . __________________ Joel '67 S3 Elan dhc (owned since 1970) '06 Audi A3 3.2 '04 Noble M12 (380 rwhp)

10-30-2009, 10:06 PM	#7 (permalink)
good2go Registered User Join Date: Mar 2007 Location: Downtown LB, California Posts: 498	Appreciate all the comments, advices, and suggestions - keep them coming. I'm learning here. It's surprising to me also that a 2zz engine had a piston slap at only 53K miles. The ticking noises made me really nervous and uncomfortable. Thus, I might have jumped the gun too quickly and had them replaced. The mechanic took out the pistons, physically/visually checked it and measured the cylinder/pistons/parts and clearance and discovered that it was piston #1. I thought about the low compression 9:1 pistons but I didn't want to take the turbo or supercharger route. However, I'm a little concern about the 12.3:1 Mahle piston's higher compression. If things don't work out - I'll get the 11.5:1 wiseco pistons which come with sleeve. Tomorrow, I'll be picking up the car in SD - I'll try to take some photos and post my initial driving impressions on the reworked engine. It's point of no return now, so wish me luck. I'll also get some correct verbage from my mechanic - I'm not mechanically inclined and don't want to misword/misquote the problem and solution. Am I the only person here getting piston slap with the 2zz engine? Thanks for the break-in tip. I also researched online and found debates on hard break-in vs. easy break-in. Last edited by good2go : 10-30-2009 at 10:39 PM.

10-31-2009, 12:45 AM	#9 (permalink)
Dragon Hydrocarbons Rule Join Date: Sep 2007 Location: Okinawa Japan Posts: 1,742 Images: 2	You can probably pick up a thicker head gasket to also drop the compression some. __________________ 2006 Exige; BWR Supercharger, Adj Sway Bar, Ohlins Suspension, BSK Oil Catch Can, Moroso Oil Pan, ORC Clutch, Custom Exhaust, Black Volk Racing CE28N's w/ Toyo R1R's, 2 piece rotors, Pagid Blue Pads, BSK Wet Carbon (Side Skirts, Front Lip Spoiler, Gas Cap Cover, Center Console, Door Panels), Dry Carbon rear Diffuser, Harness Bar, BWR Gauge Mount, OMP Superquadro steering wheel, LETSLA Short Shifter, V2arms, Rear Tow Link Brace, RLS Battery Bracket, BOE Tow Bar, Stickers.

11-01-2009, 07:51 PM	#17 (permalink)
good2go Registered User Join Date: Mar 2007 Location: Downtown LB, California Posts: 498	Update: I was all excited planning to pick up my ride yesterday when my mechanic called me...the engine pings at idle with the 12.3:1 Mahle pistons installed - probably too high of a compression - NOT a drop-in as described on MWR website. I'll try to return them! The mechanic recommended me just get the oem stock pistons from Lotus!!! Thought about Wiseco 11.25:1 pistons for 2ZZ-GE, closest to what we have without going over the stock compression... Tomorrow, I'll just call a local Toyota dealership and get stock 2zz-ge Celica GTS 11.5:1 pistons and call it a day. Keep it simple! Much cheaper than from Lotus dealership. The saga continues....damn, did I do the right thing or should I have ignored the piston slap and just drove it?.... Last edited by good2go : 11-01-2009 at 09:27 PM.

10-26-2009, 01:36 PM	#2 (permalink)
trav34 Registered User Join Date: Oct 2007 Posts: 122	Come on somebody, pipe up. I'd be interested to know if bumping the compression is ok on street gas and if it's ok with no tune.

10-30-2009, 06:59 AM	#3 (permalink)
kverges Registered User Join Date: Feb 2005 Location: Dallas Posts: 925	I would not bump compression on pump gas, esp. since Cali fuel is 91, right? Piston slap is an odd diagnosis and I'd like to know how it is diagnosed and cylinder 1. It is very hard to figure out what cylinder it is in and I am surprised to hear of it at 53K miles. Also, PS is not usuallyharmful to perfromance or longevity of engine unless it is severe - I have seen lots of engineering mules with over 300K miles and piston slap (sound is more like a tick, actually) If you are tearing into the engine, I'd go ahead and look at the bearigns and valvetrain to be sure they are not the culprit.

10-30-2009, 06:32 PM	#6 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 750	I have broken in a few motors like this: Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power The engine in my car was broken in with this method and I now have 35k on it. Standard factory compression for my car is 181psi, and that's where I'm at still. If you were going to build the motor, why not just get a lower compression ratio setup, and just buy the turbo kit that someone is selling on here? You could make a **** load of power.

10-30-2009, 10:19 PM	#8 (permalink)
vyuen Registered User Join Date: Apr 2007 Posts: 188	You can shave down your Mahle pistons to meet the stock CR spec if you're concerned

10-31-2009, 01:28 PM	#13 (permalink)
guntao Registered User Join Date: Jul 2009 Location: canada Posts: 10	i am in the same kind of situation, my block will be sleeved with darton sleeves, but now i dont know if i should stay with the stock ratio (with Mahle or wiseco) or go with just a bit more compression (Mahle has 12.3 wiseco has 12.0) also should i go with a bigger bore size ?? will it need an ecu modification ?`???

11-02-2009, 01:06 AM	#18 (permalink)
Dragon Hydrocarbons Rule Join Date: Sep 2007 Location: Okinawa Japan Posts: 1,742 Images: 2	They have a Mahle 10.5:1 compression piston on their web site that would work well. There would be minimal power loss N/A with them and it would allow you to safely add a turbo or supercharger kit with a little extra boost in the future.... Mahle Piston Set - Toyota 2zz - 10.5:1 compression 82mm - MAH-21105820 van Mahle - Monkeywrench __________________ 2006 Exige; BWR Supercharger, Adj Sway Bar, Ohlins Suspension, BSK Oil Catch Can, Moroso Oil Pan, ORC Clutch, Custom Exhaust, Black Volk Racing CE28N's w/ Toyo R1R's, 2 piece rotors, Pagid Blue Pads, BSK Wet Carbon (Side Skirts, Front Lip Spoiler, Gas Cap Cover, Center Console, Door Panels), Dry Carbon rear Diffuser, Harness Bar, BWR Gauge Mount, OMP Superquadro steering wheel, LETSLA Short Shifter, V2arms, Rear Tow Link Brace, RLS Battery Bracket, BOE Tow Bar, Stickers. Last edited by Dragon : 11-02-2009 at 01:21 AM.

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