Are my Rocker Shafts swapped? pics - LotusTalk

steve-elise · 10-06-2009, 06:52 AM

Hi guys,
As part of my continuing search for restriction in my SC 2ZZ engine, which I now believe is the cause of the excessive boost and pinging we discovered today that my rocker shafts were not correctly re-installed by a previous mechanic. I had also previously found the 2 tapered lift bolts quite loose in my engine.

Looking from the chain side of the engine, we found that both rocker shafts were around 1 1/3 inches inbound of the engine ie not flush.

If you look at the attached picture, we also noticed that on my Exhaust rocker shaft, I have highlighted what I believe to be some of the exit holes for oil used at high pressure to lift the cam. These holes are pointing inwards towards the spark plugs.

We managed to tap this exhaust rocker shaft towards the chain side of the engine, allowing the 2nd of the lift holes in the rocker shaft to become visible and allow re-insertion of the lift bolt. We did the same with the inlet cam and it too allowed us to re-insert the lift bolt into the 2nd hole (must have been in the 1st hole to begin with). Now both rocker shafts are almost flush with the chain side of the engine.

We believe that at least on the exhaust cam, prior to shifting this rocker shaft towards the chain side, the high pressure oil would just have been spraying everywhere thus preventing high lift from occurring.

I guess 2 questions for the experts

1) Does our alignment of the rocker shafts sound right and;
2) We found it a little strange that the small oil holes on the exhaust cam were pointing inwards and not outwards towards the cam - is this orientation correct or has someone swapped the inlet and exhaust rocker shafts by accident??

Many Thanks
Steve

tesprit · 10-06-2009, 08:08 AM

I don't have any photos of it, but it is very easy to install the rocker shafts in the wrong position and end up using the oil passage hole to pin the shaft in place with the pinning bolt instead of using the correct hole. When this happens, everything appears normal, but the oil passage hole is covered so there is no oil pressure to the VVT. The easiest way to tell if the shafts are installed in the correct position is to feel for the end of the rocker shaft protruding or being recessed on the cam gear side of the head. Use your fingers to feel around the rocker shaft hole in the cam gear side of the head and you should be able to feel the end of the rocker shaft being for the most part flush with the face of the head casting. If you feel the end of the rocker shaft down inside the hole or protruding out from the hole, it is in the wrong place and the oil passage hole on the shaft will be sealed off.

turbophil · 10-06-2009, 09:02 AM

+1 to above

I'm not sure what else I can add, but what the heck. I'll reword in case it might help... I'm not sure how you were able to slide the shaft from side to side unless you removed the tapered pin bolt- So I guess you did? The rotation of the shaft is also important. In otherwords, it's paramount that the tapered pin is in the correct hole on the shaft....

Those oil holes you're pointing to on the shaft are normaly covered. They basically line up with the little piston shaft on the rocker to pressurize and activate the "big cam" once the VVL solenoid directs oil into the shaft. If the holes are open, as pictured, then all that pressurized oil is doing nothing for the VVL operation-- hence your "big cam" wasn't working (better check the intake as well---- and fire the mechanic that did the work).

Also, a small technicality, the shaft you're working with has more to do with the VVL rather than the VVT

The VVT portion of the system has more to do with the unit on the end of intake cam and that control solenoid is near your oil return tube on the head...

Making progress!

Phil

steve-elise · 10-06-2009, 01:31 PM

Hi tesprit, thanks for that. We managed to use a dentist type mirror and after tapping the shafts from the non-chain side with a punch and hammer the shaft ends, are pretty much flush now with the chain side of the engine (whereas before they were recessed about an inch.

Hi Phil, thanks for the clarifications and yes the taper bolts were removed before shifting anything.

Just to be 100% sure I understand (and again pardon my mechanical ignorance - trying to learn

) If you look at my picture, the oil exit holes on the exhaust shaft are literally 180 degrees from anything 'useful' on the exhaust rockers. We just tapped that shaft inwards, towards the chain-side so they have not been rotated and those little holes (although now covered) are NOT pointing towards the cam. Because the 2 holes on each shaft (not sure why there are 2) do not go all the way through the shaft, it is not possible from what I understand to rotate that shaft and move the oil exit holes 180 degrees. I'm not sure I understand where these pistons are.

So if I'm understanding you correctly and the pistons you talk about are on the cam side and those exit holes need to line up then our suspicion that the rocker shafts could have been swapped may be correct?? As that's the only way I can see those exit holes being able to face the cams and the taper bolts being able to go in?

Or do I have some incorrect assumptions/understanding? I've attached another pic to clarify my question.

Cheers
Steve

tesprit · 10-06-2009, 02:21 PM

I can't comment on the relation of the feed holes in the shafts to the rockers having never paid attention to the positioning of them (I have always kept the rockers/shaft/cam together on the bench so they wouldn't get mixed up). Having found that the shafts were recessed about an inch into their holes means you did have them pinned in the oil feed holes and not the correct pinning holes so at least you have that part of the problem corrected. Turbophil is also correct about the VVT/VVL thing. I mistakenly typed VVT in my prior post which is actually the unit that actively changes the timing on the cam. The VVL is what is affected by an improper assembly of the rocker shafts. Perhaps turbophil can comment on the orientation of the oil feed holes in the shafts to the rockers?

steve-elise · 10-07-2009, 04:39 PM

Hi guys, quick update: We closed the engine up and there is good news and bad news.
The good news is that the overboost (10-15 PSI) is now gone and for obvious reasons, so is the pinging.

The bad news is that I am now seeing something weird - it shows 5 PSI of boost and then at around 5,500 (running Charlie's tune) we can feel some form of cam switch but immediately that happens, the boost drops to 4 PSI and stays there ??

I still have a strong suspicion that the rocker shafts have been swapped by accident and perhaps the oil exit holes are not lining up with the pistons you talk about Phil (as per my recent pic) so if you or someone can confirm this that would be great. Or if someone has some other theory why we would be seeing the cam/boost pattern I describe ie 5 PSI and then immediate drop to 4 PSI when the cam changes (or tries to)

Cheers
Steve

Demonized · 10-07-2009, 05:43 PM

It's perfectly normal for the boost pressure to drop after the cam switch, it should creep back up near redline though.

steve-elise · 10-08-2009, 09:49 AM

Hi Demonized, boost pattern looks very weird though. If I floor it in second it has 5 PSI almost immediately and holds this till about 5,500 RPM then as the cam changes it drops immediately to 4 PSI and does not go up from there. What does your boost pattern look like?

Phil or other experts

Any thoughts on the rocker shafts possibly facing the wrong direction or do they look right?

Cheers
Steve

ZTEC · 10-08-2009, 10:14 AM

That boost drop was normal on my Katana'd car...7 to 5 at cam switch then a slow rise to redline!

steve-elise · 10-10-2009, 03:10 AM

Hi guys,
Firstly a big thank you to everyone for their advice and help. This was quite a challenging one because the actual Toyota installation/removal information is very light on and as some people have said, almost incorrect.

I have posted some pictures below thanks to James Clayton

who very kindly went out of his way to take some detailed pictures of an engine at work, showing the intake and exhaust rocker shafts which I have annotated to highlight the differences in case anyone else has a similar problem.

One of the best tell-tale signs to ensure correct installation is
a) Both rocker shafts aligning pretty much flush with the chain side of the engine
b) The slots on the intake and exhaust rocker shafts offset at a slight angle as described in the pictures below and as shown in my diagram taking out of the lift-bolt TSB from Toyota.

Hope this info helps someone else in the future
Cheers
Steve

10-06-2009, 06:52 AM	#1 (permalink)
steve-elise Registered User Join Date: Jul 2009 Posts: 38	Are my Rocker Shafts swapped? pics Hi guys, As part of my continuing search for restriction in my SC 2ZZ engine, which I now believe is the cause of the excessive boost and pinging we discovered today that my rocker shafts were not correctly re-installed by a previous mechanic. I had also previously found the 2 tapered lift bolts quite loose in my engine. Looking from the chain side of the engine, we found that both rocker shafts were around 1 1/3 inches inbound of the engine ie not flush. If you look at the attached picture, we also noticed that on my Exhaust rocker shaft, I have highlighted what I believe to be some of the exit holes for oil used at high pressure to lift the cam. These holes are pointing inwards towards the spark plugs. We managed to tap this exhaust rocker shaft towards the chain side of the engine, allowing the 2nd of the lift holes in the rocker shaft to become visible and allow re-insertion of the lift bolt. We did the same with the inlet cam and it too allowed us to re-insert the lift bolt into the 2nd hole (must have been in the 1st hole to begin with). Now both rocker shafts are almost flush with the chain side of the engine. We believe that at least on the exhaust cam, prior to shifting this rocker shaft towards the chain side, the high pressure oil would just have been spraying everywhere thus preventing high lift from occurring. I guess 2 questions for the experts 1) Does our alignment of the rocker shafts sound right and; 2) We found it a little strange that the small oil holes on the exhaust cam were pointing inwards and not outwards towards the cam - is this orientation correct or has someone swapped the inlet and exhaust rocker shafts by accident?? Many Thanks Steve Attached Images

10-06-2009, 09:02 AM	#3 (permalink)
turbophil Plug Whisperer Join Date: Dec 2005 Location: Kansas City/ Overland Park Posts: 2,544 Images: 6	+1 to above I'm not sure what else I can add, but what the heck. I'll reword in case it might help... I'm not sure how you were able to slide the shaft from side to side unless you removed the tapered pin bolt- So I guess you did? The rotation of the shaft is also important. In otherwords, it's paramount that the tapered pin is in the correct hole on the shaft.... Those oil holes you're pointing to on the shaft are normaly covered. They basically line up with the little piston shaft on the rocker to pressurize and activate the "big cam" once the VVL solenoid directs oil into the shaft. If the holes are open, as pictured, then all that pressurized oil is doing nothing for the VVL operation-- hence your "big cam" wasn't working (better check the intake as well---- and fire the mechanic that did the work). Also, a small technicality, the shaft you're working with has more to do with the VVL rather than the VVT The VVT portion of the system has more to do with the unit on the end of intake cam and that control solenoid is near your oil return tube on the head... Making progress! Phil __________________ \| '05 GG LSS Elise \| A Track Chariot \| BOE ClamHinge \| BOE TVS SuperCharger 280whp/180wtq \| EFI Standalone Engine Management \| BOE Fuel Surge System \| BOE Lotus Tow Package See my car at BOE Fabrication: www.boefabrication.com *----->Last Updated: 9/25/2009* If something ain't worth doing right, it ain't worth doing... *Whoever thought working on a Lotus is hard, clearly hasn't tried it. Pick up a wrench and get some grease under your nails*

10-06-2009, 01:31 PM	#4 (permalink)
steve-elise Registered User Join Date: Jul 2009 Posts: 38	Hi tesprit, thanks for that. We managed to use a dentist type mirror and after tapping the shafts from the non-chain side with a punch and hammer the shaft ends, are pretty much flush now with the chain side of the engine (whereas before they were recessed about an inch. Hi Phil, thanks for the clarifications and yes the taper bolts were removed before shifting anything. Just to be 100% sure I understand (and again pardon my mechanical ignorance - trying to learn ) If you look at my picture, the oil exit holes on the exhaust shaft are literally 180 degrees from anything 'useful' on the exhaust rockers. We just tapped that shaft inwards, towards the chain-side so they have not been rotated and those little holes (although now covered) are NOT pointing towards the cam. Because the 2 holes on each shaft (not sure why there are 2) do not go all the way through the shaft, it is not possible from what I understand to rotate that shaft and move the oil exit holes 180 degrees. I'm not sure I understand where these pistons are. So if I'm understanding you correctly and the pistons you talk about are on the cam side and those exit holes need to line up then our suspicion that the rocker shafts could have been swapped may be correct?? As that's the only way I can see those exit holes being able to face the cams and the taper bolts being able to go in? Or do I have some incorrect assumptions/understanding? I've attached another pic to clarify my question. Cheers Steve Attached Images Last edited by steve-elise : 10-06-2009 at 01:54 PM. Reason: Added another pic for clarification

10-07-2009, 04:39 PM	#6 (permalink)
steve-elise Registered User Join Date: Jul 2009 Posts: 38	Hi guys, quick update: We closed the engine up and there is good news and bad news. The good news is that the overboost (10-15 PSI) is now gone and for obvious reasons, so is the pinging. The bad news is that I am now seeing something weird - it shows 5 PSI of boost and then at around 5,500 (running Charlie's tune) we can feel some form of cam switch but immediately that happens, the boost drops to 4 PSI and stays there ?? I still have a strong suspicion that the rocker shafts have been swapped by accident and perhaps the oil exit holes are not lining up with the pistons you talk about Phil (as per my recent pic) so if you or someone can confirm this that would be great. Or if someone has some other theory why we would be seeing the cam/boost pattern I describe ie 5 PSI and then immediate drop to 4 PSI when the cam changes (or tries to) Cheers Steve Last edited by steve-elise : 10-07-2009 at 05:20 PM.

10-07-2009, 05:43 PM	#7 (permalink)
Demonized NOT ßANNED! Join Date: Aug 2008 Location: Colorado Posts: 1,546	It's perfectly normal for the boost pressure to drop after the cam switch, it should creep back up near redline though. __________________ 2005 Saffron Yellow Elise, Katana Supercharger, LSS Wheels, 2Bular exhaust & cat, rear panel delete, Cup Airbox, Volt / Oil temp gauge, Ohlins double adjustable coilovers, Dual Oil Coolers, S111 RTD Brace, Moroso Oil Pan, MicroMirror, S111 "V-Force" Harness bar, Manly Engine Mounts, Odyssey PC680 & RLS Bracket, Saikou Michi OCC, CF Scoops, CF Bootlid, CF Front Lip.

10-06-2009, 08:08 AM	#2 (permalink)
tesprit Registered User Join Date: Apr 2006 Location: Racine, WI Posts: 1,925	I don't have any photos of it, but it is very easy to install the rocker shafts in the wrong position and end up using the oil passage hole to pin the shaft in place with the pinning bolt instead of using the correct hole. When this happens, everything appears normal, but the oil passage hole is covered so there is no oil pressure to the VVT. The easiest way to tell if the shafts are installed in the correct position is to feel for the end of the rocker shaft protruding or being recessed on the cam gear side of the head. Use your fingers to feel around the rocker shaft hole in the cam gear side of the head and you should be able to feel the end of the rocker shaft being for the most part flush with the face of the head casting. If you feel the end of the rocker shaft down inside the hole or protruding out from the hole, it is in the wrong place and the oil passage hole on the shaft will be sealed off.

10-06-2009, 02:21 PM	#5 (permalink)
tesprit Registered User Join Date: Apr 2006 Location: Racine, WI Posts: 1,925	I can't comment on the relation of the feed holes in the shafts to the rockers having never paid attention to the positioning of them (I have always kept the rockers/shaft/cam together on the bench so they wouldn't get mixed up). Having found that the shafts were recessed about an inch into their holes means you did have them pinned in the oil feed holes and not the correct pinning holes so at least you have that part of the problem corrected. Turbophil is also correct about the VVT/VVL thing. I mistakenly typed VVT in my prior post which is actually the unit that actively changes the timing on the cam. The VVL is what is affected by an improper assembly of the rocker shafts. Perhaps turbophil can comment on the orientation of the oil feed holes in the shafts to the rockers?

10-08-2009, 09:49 AM	#8 (permalink)
steve-elise Registered User Join Date: Jul 2009 Posts: 38	Hi Demonized, boost pattern looks very weird though. If I floor it in second it has 5 PSI almost immediately and holds this till about 5,500 RPM then as the cam changes it drops immediately to 4 PSI and does not go up from there. What does your boost pattern look like? Phil or other experts Any thoughts on the rocker shafts possibly facing the wrong direction or do they look right? Cheers Steve

10-08-2009, 10:14 AM	#9 (permalink)
ZTEC Third Eye Open Join Date: Jan 2006 Location: Florida Posts: 1,737 Images: 3	That boost drop was normal on my Katana'd car...7 to 5 at cam switch then a slow rise to redline! __________________ GO: Vision Function Stage II Intercooled Bliss with Charlie's ECU magic and Ronin's Tenacity! STOP: DBA 4000's, Porterfield R4! TURN: Nitron S/A's Toyo RA1's 225/245 on Rota's!

10-10-2009, 03:10 AM	#10 (permalink)
steve-elise Registered User Join Date: Jul 2009 Posts: 38	Solution Information Hi guys, Firstly a big thank you to everyone for their advice and help. This was quite a challenging one because the actual Toyota installation/removal information is very light on and as some people have said, almost incorrect. I have posted some pictures below thanks to James Clayton who very kindly went out of his way to take some detailed pictures of an engine at work, showing the intake and exhaust rocker shafts which I have annotated to highlight the differences in case anyone else has a similar problem. One of the best tell-tale signs to ensure correct installation is a) Both rocker shafts aligning pretty much flush with the chain side of the engine b) The slots on the intake and exhaust rocker shafts offset at a slight angle as described in the pictures below and as shown in my diagram taking out of the lift-bolt TSB from Toyota. Hope this info helps someone else in the future Cheers Steve Attached Images

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode