Discussion - 2zzge

[Mooro]

So I have a 2005 model Corolla Sportivo 2zzge halfcut which I'm intending to convert into my AW11 MR2. I have been doing a fair amount of reading about the 2zzge and I do find it concerning the amount of stories on the web of them failing. It seems that it doesn't share the reputation for reliability of it's older brothers like the 4age and 3sge. So I've been doing some thinking/research into its weaknesses and potential affordable solutions. The good news is that the general design of the 2zzge seems sound, it just has a few weaknesses which let it down, mainly to do with the lubrication system.

As we all know the aftermarket for the 2zzge is not anywhaere near the level of corresponding Honda motors and what is available is very expensive, so for the average punter it is going to require some thinking outside the square to come up with affordable solutions.

Anyway here is my list of weakness and my thoughts on improving them. I'm keen to hear other peoples thoughts and ideas.

1. Lift Bolts - not a huge concern to me since I don't believe it will cause major damage to the engine....so replace them with improved items if/when they fail.

2. Over-Rev due to Missshifting - this seems to be caused by a combination of a notchy gearbox, and poorly placed rev limit and lift engagement points causing people to aim for the quickest shift possible. Due to wiring difficulties I will most likely end up running a PowerFC so I will be lowering the lift engagement point to somewhere around 5,700rpm. I will keep fuel cut at 8,200rpm due to other weaknesses in the engine at these revs. This should ease the pressure off the gear change and with sensible driving I should still be able to land in lift without risking a mis-shift.

3. Valve Springs - apparently become a problem once the rev limit is increased. The only option I see is to replace them which is not really a budget option. For now I will just keep my rev-limit at 8,200rpm and leave them stock.

4. Rod Bearings - apparently these are prone to failure being made form a softer metal. Softer metail is good for low maintenance engines (more tolerant of crap in the oil) but in sustained high revs they can become an issue. Again only option is to replace them with aftermarket alternatives. Not really a cheap option and I'm hoping with stock items will be fine with other improvements to the lubrication system combined with good maintenance and stock rev limit.

5. Oil Starvation - the dreaded 1G limit with the oil sump. My MR2 will have coilovers, decent tyres and will be driven hard at times so I could potentially see over 1G corning loads. There are a couple of aftermarket options here from MWR and Moroso but at $500US plus shipping, it's not going to be cheap :(. THere was a guy on NewCelica who was offering to modify the stock item with baffles for ~$170 US but that seems to have died. To me, for a car that only sees occasion track duties, a modified stock item seems suficient. Problem is, poorly designed modification could make the problem worse, so I'm not sure how to go about it. I'm open to suggestions here on who can modify them and how to design an appropriate system. I know there are a couple of sauccessful Celicas in production racing, perhaps if we could get in touch with those teams they will be able to help as presumably they have resolved this issue.

6. Oil Pump Gear - once the oil pump sucks air or under sustained high revs the oil pump gear has been known to be marginal, and if it fails it causes catastrophic failure of the engine. There were some stronger aftermarket options around but I think they are no longer available and where quite expensive for a fairly simple item. My only idea is that we could just remove the stock item and have it crygenically treated. Cryo treatment offers a significant improvement in strength and is very cheap. Perhaps it will be enough just to provide that extra margin for safety. Thoughts?

Long post I know but I think if we combine everyones knowledge and with some lateral thinking and backyard ingenuity we might be able to get rid of the few weaknesses in the 2zzge and turn it into a reliable, power productive little banger, so please discuss the above :)

[Rolla_Boy]

1. Reading on here or somewhere else that problem is solved, i cant prove it but im sure i read it somewhere & someone else will mention it too.

2. Get a clutch adjustment it has fixed my shifting in lift

3.You said your not raising your limit so it doesnt matter. :P

There the only 3 i can help you with lol

[MR22ZZ]

1. Lift Bolts - I believe the lift bolts were revised by the time the Sportivo engine came out.

2. Over-Rev due to Missshifting - At the end of the day, it comes down to driver error. I don't know any engine that would look very healthy when you are at 8,200 rpm and you hope to go up to 5th and accidentally slot into 3rd.

3. Valve Springs - The guys here running the Apexi PFC have found an 8,500-8,600 RPM rev limit to be OK, it's only once you start to push 9,000 and beyond they problems arise.

4. Rod Bearings - I believe this is one of the reasons that Toyota recommend changing the oil every 5000 kms on these engines. I haven't look into alternatives but if/when I get the engine stroke kit they will of course be changed.

5. Oil Starvation - I'm getting the Moroso sump myself... no questions there at all.

6. Oil Pump Gear - prevention again here, it far better then the cure. Simply don't allow the pump to pass any air (see no. 5)

[Northy]

1. Covered

2. With the clutch adjusted correctly and the Power FC running a lift point of 5,700RPM you wont have any probs making shifts and staying in lift.

3. Both Xoom and myself started with 8,700RPM fuel cuts on stock internals untill mine dropped a rod, I am now using the stock fuel cut untill my new internals arrive. Xoom is up around the 8,400rpm mark with his rebuilt Turbo setup.

4. Covered

5. The Moroso sump is cheap insurance against Oil Starvation another item that I will be getting

6. Covered.

[Mooro]

OK so if I keep rev limit to 8,200 and lift engagement at around 5,700rpm, regular maintenance, avoid mis-shifts (I agree, it's an obvious thing), and invest in moroso sump or modify existing with baffles, then the engine should be fairly reliable. Sounds good enough to me.

A higher rev-limit would be nice but there doesn't seem to be much of a safety margin there so I will keep it at 8,200rpm

Edited September 5, 2007 by Mooro

[Northy]

with the stock cams there isn't much point going over the stock rev limit as the power gains are small and the change of doing serious damage is Big.

[CAP]

Where are you located Mooro?, perhaps you can meet some of the other members and exchange idea's in person.

[Mooro]

Yeh I was more meaning to make gearshifts into lift easier but I guess lowering the lift point will help.

General consensus seems to be that 5,700rpm is about right? I have head stories of people going down to 5,200rpm etc but I'm presuming you lose power because the small cam is more efficient than the big cam at those revs?

[Mooro]

Where are you located Mooro?, perhaps you can meet some of the other members and exchange idea's in person.

I'm in Perth. Sucks being over here cos all the good stuff seems to be over East. I know MR22ZZ is doing the same conversion so it would have been perfect if we lived in the same state :9

[Northy]

Yeh I was more meaning to make gearshifts into lift easier but I guess lowering the lift point will help.

General consensus seems to be that 5,700rpm is about right? I have head stories of people going down to 5,200rpm etc but I'm presuming you lose power because the small cam is more efficient than the big cam at those revs?

spot on the money mate.

[MT]

PM Neil Trama.

Only info required. Close thread ;)

[Mooro]

PM sent to Neil :)

[MT]

PM sent to Neil :)

He's only on here sparingly... so if it takes a while... sorry :(

[44gze]

the one thing you havent touched on is the gearbox weakness as I found out this week it is easily destroyed hey Corey lol

[JF-GEE4CE]

only when you dont no how to drive lol

[xoom]

the one thing you havent touched on is the gearbox weakness as I found out this week it is easily destroyed hey Corey lol

totally disagree !!!!!!! im putting out twice the power of a stock stivo with no issues

only when you dont no how to drive lol

totally agree !!!!!!!

back to driving lessons for corey and urself luke :P :P :P :P :P :lol: :lol:

[selyaT]

the one thing you havent touched on is the gearbox weakness as I found out this week it is easily destroyed hey Corey lol

I don't think it's weak but the gearing is way too tall

[Northy]

the one thing you havent touched on is the gearbox weakness as I found out this week it is easily destroyed hey Corey lol

totally disagree !!!!!!! im putting out twice the power of a stock stivo with no issues

only when you dont no how to drive lol

totally agree !!!!!!!

back to driving lessons for corey and urself luke :P :P :P :P :P :lol: :lol:

mate i havn't broken my box yet....

[selyaT]

Why "Yet" Corey?

[MT]

he know's its inevitable.

We've got bets going on when and how.

[Mooro]

Neil replied almost immediately :) I gotta give him a call to discuss options when I find some time.

Gearboxs are basically the same as all the other C series boxes right so it should be fine at the relatively stock power levels I'll be at (~200hp). The AW11 will be about 300kgs lighter than the sportivo which will help as well but then it will also have superior traction which wont help :(

I've heard gearing is a bit dodge but the lower lift engagement should help here.

[stuart bauer]

so this apparent clutch adjustment should solve the shift problems. I have been having a few issues every now and then shifting from 2nd to 3rd in a 03 sportivo i just purchased. So can most toyota dealerships fix this as i live out Campbelltown way and i dont really want to travel to Castlehill to get it done. Anyone know which toyota dealerships can do this mod.

thanks guys.

[Guest JDM y0 !]

ignition cut is better than fuel cut.

plus you get hektic flames too lol. but fuel cut starve the engine of fuel at big revs, not the most ideal.