Another wiped Cam but a bit different! - Page 9 - LotusTalk - The Lotus Cars Community
 2Likes
Reply
 
LinkBack Thread Tools Display Modes
post #161 of 287 (permalink) Old 04-24-2011, 11:35 AM
Registered User
 
trav34's Avatar
 
Join Date: Oct 2007
Posts: 304
I think the sticking valve theory is gaining traction. My engine just ate its 2nd intake cam in less than a year. This time however, it was catastrophic and without warning. My intake cam looks very similar to apexdc's. When I replaced it last summer I opened the lash up to like .012-.013. I haven't got the engine pulled out yet but it appears an intake valve met up with the piston while coming down the back straight at VIR. I'm interested in hearing thoughts on this because I'm more than a little nervous about rebuilding the engine and not having a rock solid cause identified. When I get the engine apart, it might become more obvious what caused it, but for now
Attached Images
 
trav34 is offline  
Sponsored Links
Advertisement
 
post #162 of 287 (permalink) Old 04-29-2011, 06:45 AM
Registered User
 
DWebb's Avatar
 
Join Date: Aug 2008
Location: Comfort, Texas
Posts: 339
FWIW, My cam had that pattern of wear with regards to the area identified 2 posts ago. Only 6k miles later I dropped a valve through #2 piston.
You may see all my videos of my engine on my Youtube search "3dw3dw"

The sticking valve theory may have some credibility.
I'm still thinking about it......but doesn't it fit after viewing the progression of my miseries.
HMMMmmmmm....

05 BRG Elise - 9:1 built motor- rev 400 66mm pulley
04 Yamaha R6
02 Volvo S80
92 Toyota Previa
DWebb is offline  
post #163 of 287 (permalink) Old 04-29-2011, 12:24 PM
Registered User
 
trav34's Avatar
 
Join Date: Oct 2007
Posts: 304
The more I look at the situation, the more I think it's valve float. I'll get my head apart soon and a can do some measurements on the valves and valve springs to see if I can substantiate that theory. I think the sticking valve theory is unlikely given where the intake valves are when they're open relative to where the piston is from TDC. I would think that there would be a loss in power prior to the big bang if intake valves were sticking open. The fact that all of my intake cam lobes look identical and that the wear is on the back side of the lobes all seem to point to float IMO.
trav34 is offline  
 
post #164 of 287 (permalink) Old 04-29-2011, 04:16 PM
Registered User
 
apexdc's Avatar
 
Join Date: Jan 2006
Location: Palm Springs, CA
Posts: 985
Quote:
Originally Posted by trav34 View Post
The more I look at the situation, the more I think it's valve float. I'll get my head apart soon and a can do some measurements on the valves and valve springs to see if I can substantiate that theory. I think the sticking valve theory is unlikely given where the intake valves are when they're open relative to where the piston is from TDC. I would think that there would be a loss in power prior to the big bang if intake valves were sticking open. The fact that all of my intake cam lobes look identical and that the wear is on the back side of the lobes all seem to point to float IMO.
How hot was the temp when the valve imploded? Oil fully warmed up??

2006 Elise, Graphite Grey/Red leather, Sport Elise Suspension, Cup airbox, ECU ref lash, MonoBalls, etc. etc.
1992 900SS Ducati Race Spec Built by Ferracci
2006 KTM 950 SuperMoto, a work in progress

Old stuff gone: Ferrari 275GTB/4, '69 1275 Cooper S. '72 500 Fiat, old Jags, etc. Never bought a boring car.
apexdc is offline  
post #165 of 287 (permalink) Old 04-29-2011, 06:51 PM
Registered User
 
trav34's Avatar
 
Join Date: Oct 2007
Posts: 304
Yeah she was warmed up thoroughly. It was about 5-10 minutes into my 2nd session. I got the engine apart last night. 1st pic is what I saw when I pulled the intake manifold. I noticed there was crap rattling around in the manifold, so I knew it would be ugly. 2nd pic is about what you would expect when a valve fails somewhere north of 7k rpm.
Attached Images
   
trav34 is offline  
post #166 of 287 (permalink) Old 05-01-2011, 05:39 AM
Registered User
 
DWebb's Avatar
 
Join Date: Aug 2008
Location: Comfort, Texas
Posts: 339
Regardless of the cause. This is a great opportunity to "build" a better engine. We all know what causes problems with these motors. This is the time to correct them.

Now that Ferrea is making the dual valve springs and valves for this engine. It should be IMO settled.

I think it's kinda funny that you don't hear alot of this from the celica guys.

WTF?

05 BRG Elise - 9:1 built motor- rev 400 66mm pulley
04 Yamaha R6
02 Volvo S80
92 Toyota Previa
DWebb is offline  
post #167 of 287 (permalink) Old 05-01-2011, 01:44 PM
Registered User
 
apexdc's Avatar
 
Join Date: Jan 2006
Location: Palm Springs, CA
Posts: 985
Quote:
Originally Posted by DWebb View Post
Regardless of the cause. This is a great opportunity to "build" a better engine. We all know what causes problems with these motors. This is the time to correct them.

Now that Ferrea is making the dual valve springs and valves for this engine. It should be IMO settled.

I think it's kinda funny that you don't hear alot of this from the celica guys.

WTF?
I would normally agree with you and have, many times, followed my own "logic" of, if it just blew up, probably because it was overstressed in some way, this is an excellent time to add a more radical cam, higher compression, etc. etc. It might not have made sense, but I sure loved doing it, even if the cycle never seemed to stop.

In this case, however, I was "assuming" (bad idea), that if I left the motor pretty much stock, which I did, then it would be as bulletproof as a Miata, if not more so. Weeeeeell, it seems that Toyota doesn't quite have that nailed.

Allen Strommer at Mulholland Motorsports is replacing my cam. He said that his feeling is that Toyota got a run of bad intake cams. He has replaced 15-16 of them and only had one fail again. The vast majority of cams he has used were bought from Toyota. The one that failed again was a Lotus part. That makes sense, as they would have bought spares when they bought the engines.

I hope that is the cause, but I am still going to be VERY careful that my oil temps are up before going to the high cam. That won't hurt anything and might help if the sticky valve theory has some merit.

And I agree fully that it is odd the Celica guys don't seem to have problems. I have done searches for wiped cams in Celicas and found nothing.


2006 Elise, Graphite Grey/Red leather, Sport Elise Suspension, Cup airbox, ECU ref lash, MonoBalls, etc. etc.
1992 900SS Ducati Race Spec Built by Ferracci
2006 KTM 950 SuperMoto, a work in progress

Old stuff gone: Ferrari 275GTB/4, '69 1275 Cooper S. '72 500 Fiat, old Jags, etc. Never bought a boring car.
apexdc is offline  
post #168 of 287 (permalink) Old 06-12-2011, 01:41 PM
Registered User
 
Join Date: Jun 2011
Location: pl
Posts: 1
Hi,
I have the same problem with 3 wiped cam lobes and rockers in my 2zz-powered eu corolla. I think I'll go with piper stage 1 or piper stage 2, but the question is - do I need to replace my valve springs or retainers to run stage 2 safely? I'm on stock ecu, the car is 192hp 2zz with stock 8200rpm rev limit. Any help would be appreciated
jawor is offline  
post #169 of 287 (permalink) Old 07-07-2011, 02:59 PM
Registered User
 
sleepe's Avatar
 
Join Date: Jan 2007
Location: Rehoboth Beach, Delaware
Posts: 3,012
Yet another>>>but please verify damage

2006 Elise 32000 miles
How do I know if anything else is damaged?
-Robert
Attached Images
         

2006 Elise ST (someone else has it now . . . )
2008 Exige S240 ST
sleepe is offline  
post #170 of 287 (permalink) Old 07-07-2011, 03:01 PM
Registered User
 
sleepe's Avatar
 
Join Date: Jan 2007
Location: Rehoboth Beach, Delaware
Posts: 3,012
here are more
Attached Images
         

2006 Elise ST (someone else has it now . . . )
2008 Exige S240 ST
sleepe is offline  
post #171 of 287 (permalink) Old 07-07-2011, 03:06 PM
Registered User
 
trav34's Avatar
 
Join Date: Oct 2007
Posts: 304
Pull the head and install new valves & springs. Mine looked nearly identical last year and I installed a new cam and rockers. A few trackdays later I sent an intake valve thru a piston and completely ruined my engine. You might be able to change it out and open the lash up a bit (as I did) and be fine, but in my opinion it's just not worth the risk. My 2 cents...
trav34 is offline  
post #172 of 287 (permalink) Old 07-07-2011, 03:18 PM
Puff Daddy
 
Bane's Avatar
 
Join Date: May 2005
Location: Earth
Posts: 3,872
Yikes that looks pretty bad. I'd suggest to start building another motor... especially if you track the car. If that's too extreme you have a lot of options for just replacing the cams.

If/when this happens to me I'll probably buy a Monkey Wrench cylinder head. It looks like an excellent piece at a very reasonable price.

MWR Built Cylinder Head - Toyota 2ZZ-GE - Ferrea Valvetrain - MWR-220X5X van Monkeywrench Racing -

I'd also consider a BOE Nikasil short block while you're at it.

On another note... did you take the valve cover off underneath a tree??
Bane is offline  
post #173 of 287 (permalink) Old 07-07-2011, 03:28 PM
Moderator Extraordinaire!
 
tesprit's Avatar
 
Join Date: Apr 2006
Location: Sharpsburg, GA
Posts: 2,843
Quote:
Originally Posted by Bane View Post
On another note... did you take the valve cover off underneath a tree??
Shade tree mechanic?
tesprit is offline  
post #174 of 287 (permalink) Old 07-07-2011, 04:42 PM
Registered User
 
sleepe's Avatar
 
Join Date: Jan 2007
Location: Rehoboth Beach, Delaware
Posts: 3,012
Quote:
Originally Posted by Bane View Post
Yikes that looks pretty bad. I'd suggest to start building another motor... especially if you track the car. If that's too extreme you have a lot of options for just replacing the cams.

If/when this happens to me I'll probably buy a Monkey Wrench cylinder head. It looks like an excellent piece at a very reasonable price.

MWR Built Cylinder Head - Toyota 2ZZ-GE - Ferrea Valvetrain - MWR-220X5X van Monkeywrench Racing -

I'd also consider a BOE Nikasil short block while you're at it.

On another note... did you take the valve cover off underneath a tree??
No, but some plant matter did get in the motor. I fished it out though.

Would anything else need to done if the monkey wrench built cylinder head
were to replace the stock head? I think they can pre-install the camshafts too. How difficult an install would this be for the 'everymans' mechanic?
-Robert

2006 Elise ST (someone else has it now . . . )
2008 Exige S240 ST
sleepe is offline  
post #175 of 287 (permalink) Old 07-07-2011, 04:46 PM
Registered User
 
sleepe's Avatar
 
Join Date: Jan 2007
Location: Rehoboth Beach, Delaware
Posts: 3,012
Quote:
Originally Posted by trav34 View Post
Pull the head and install new valves & springs. Mine looked nearly identical last year and I installed a new cam and rockers. A few trackdays later I sent an intake valve thru a piston and completely ruined my engine. You might be able to change it out and open the lash up a bit (as I did) and be fine, but in my opinion it's just not worth the risk. My 2 cents...
Please explain why replacing the camshafts only is not the best solution.
Should the rockers be replaced too? Anything else?

I think the monkeywrench built head is a good option with the preinstalled camshafts. Is this a literal 'drop-in' fix, simple swap? What else is needed if I were to use the MW built head? I need this done a fast as possible, school begins soon.

Does a DIY tutorial exist for replacing the camshafts or the whole head? I hear the clam does not need to be removed on a Elise....true?
How is this done with clam on?

thanks for any guidance......

Is it safe to drive the car a short distance to a shop if I don't use the 2nd cam( 2nd cam is rpms above 5500 for vf2 kit I think)
-Robert

2006 Elise ST (someone else has it now . . . )
2008 Exige S240 ST

Last edited by sleepe; 07-07-2011 at 04:52 PM.
sleepe is offline  
post #176 of 287 (permalink) Old 07-07-2011, 05:42 PM
Puff Daddy
 
Bane's Avatar
 
Join Date: May 2005
Location: Earth
Posts: 3,872
You'll need at minimum a new headgasket and new head studs if you go with the MWR option.

It's not an "easy" task but it's not super difficult either. I wouldn't even attempt it with the clam on but it's probably possible. The 3 hours or so it'll take to remove the rear clam will be well worth it for a large job like this IMO.
Bane is offline  
post #177 of 287 (permalink) Old 07-07-2011, 06:13 PM
Registered User
 
sleepe's Avatar
 
Join Date: Jan 2007
Location: Rehoboth Beach, Delaware
Posts: 3,012
What is the 'maximum' of what I should replace for a head swap?

head studs+head gasket+....

2006 Elise ST (someone else has it now . . . )
2008 Exige S240 ST
sleepe is offline  
post #178 of 287 (permalink) Old 07-07-2011, 06:14 PM
Registered User
 
trav34's Avatar
 
Join Date: Oct 2007
Posts: 304
Quote:
Originally Posted by sleepe View Post
Please explain why replacing the camshafts only is not the best solution.
Should the rockers be replaced too? Anything else?

I think the monkeywrench built head is a good option with the preinstalled camshafts. Is this a literal 'drop-in' fix, simple swap? What else is needed if I were to use the MW built head? I need this done a fast as possible, school begins soon.

Does a DIY tutorial exist for replacing the camshafts or the whole head? I hear the clam does not need to be removed on a Elise....true?
How is this done with clam on?

thanks for any guidance......

Is it safe to drive the car a short distance to a shop if I don't use the 2nd cam( 2nd cam is rpms above 5500 for vf2 kit I think)
-Robert
Weak valve springs are a common culprit for the the kind of wear present in your pictures. The rockers have to be replaced as well, you'll see why when you get the camshaft out. I replaced my cam with the clam on, and wouldn't be afraid to tackle the head as well (I'd probably search on here a bit for pro's & con's before I made my final decision). I recently removed my clam to pull the blown engine and it took me more like 5 hours. If you're in a hurry and/or don't have a local machine shop that you could take the head to to have the work done, I'd say buying a head already set-up would be a good investment. Make sure they set the lash a little looser(.013 intake, .016 exhaust) than what lotus/toyota recommend since factory lash settings have been blamed for many a dead camshaft. I'd say you're fine driving it as long as you're easy on it. Best of luck to you.
trav34 is offline  
post #179 of 287 (permalink) Old 07-07-2011, 06:30 PM
Moderator Extraordinaire!
 
tesprit's Avatar
 
Join Date: Apr 2006
Location: Sharpsburg, GA
Posts: 2,843
Quote:
Originally Posted by sleepe View Post
Please explain why replacing the camshafts only is not the best solution.
Should the rockers be replaced too? Anything else?

I think the monkeywrench built head is a good option with the preinstalled camshafts. Is this a literal 'drop-in' fix, simple swap? What else is needed if I were to use the MW built head? I need this done a fast as possible, school begins soon.

Does a DIY tutorial exist for replacing the camshafts or the whole head? I hear the clam does not need to be removed on a Elise....true?
How is this done with clam on?

thanks for any guidance......

Is it safe to drive the car a short distance to a shop if I don't use the 2nd cam( 2nd cam is rpms above 5500 for vf2 kit I think)
-Robert
The camshafts are replaced along with the rockers/followers as a set and are purchased that way as well. The reason for the valve failures after a cam/follower replacement is most likely the result of the hammering the valve stems took from the increased clearance resulting from the worn cam lobes on the old cam. The new cam and followers will fix the clearance problem, but depending on how badly worn the old cam lobes were and how long the engine was run with the worn parts, the damage to the valves may already be present when the new cam and followers are swapped in so it is just a matter of time before a damaged valve fails. It is hard to say whether it is going to be a problem with your engine after a simple cam/follower replacement but if you have been running your engine hard for a long time with a failed cam, it would be prudent to have the valves inspected at the very least, but this will require removal of the head and full disassembly of it so you might as well freshen and upgrade the entire head at that time. The simple method is to buy the head already done by Monkey Wrench and swap it in for your old head, but again its your call. As far as a tutorial for replacing the cam in your Elise without removing your clam, PM me with your email address and I will send you one. I took notes while my cam and followers were replaced without removing the clam and wrote up step by step instructions afterward.
tesprit is offline  
post #180 of 287 (permalink) Old 07-07-2011, 10:10 PM
Registered User
 
luxige's Avatar
 
Join Date: Jun 2007
Location: MA
Posts: 2,524
One more small point…if you buy a set-up head, you will need to remove the camshafts to bolt the head in.

In theory, there is no difference between Theory and Practice. In practice, there is. - Y. Berra
luxige is offline  
Sponsored Links
Advertisement
 
Reply

  LotusTalk - The Lotus Cars Community > Lotus Discussions > Powertrain (Engine, Transmission, etc)

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the LotusTalk - The Lotus Cars Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome