82mm 1.93L 1zz rebuild project

[Anonymous]

Whilst my MR2 is away getting a V6 put in by Woodsport (with supercharger for that on standby), I have started (well, finished...) stripping down my old fully forged & bored out 1zz. The only really interesting piccies from this are the pistons. Now, I ran this engine in using the 'balls to the wall' method where you basically thrash the nuts off the thing from the word go. The piccies show that the rings were sealing wonderfully following this run-in procedure which basically shows it is a good method to use. The engine ran 8000 road miles with me thrashing the nuts off it + running in on the dyno and a fair bit of other dyno time... Check it:





The block is going up to Agra engineering in Dundee for an inspection of the bores and a possible glaze-break as well as a skim of the face. The head is getting skimmed as well then a few new gaskets & bearings and it goes back together.

I will put up some piccies of the engine + custom manifold / s/c mounts as and when I bolt it back together in the living room in the coming months.

[philster_d]

I read a whole lot on the net about this method that realy settles the rings in in stead of a realy long slow run in where they are potentialy never realy settled properly.

very interesting.

phil

[Tem]

I read a whole lot on the net about this method that realy settles the rings in in stead of a realy long slow run in where they are potentialy never realy settled properly.

very interesting.

Probably this page? At least this one seems to get mentioned most often:
 m http://www.mototuneusa.com/break_in_secrets.htm m

I've done my last two builds like that and have nothing to complain. Stock 1ZZ actually dynoed a 149hp after that on a same dyno where it made 140hp in stock form. I'm a believer.

[Anonymous]

Lots of progress on this now; engine re-honed, head & block skimmed, fresh bearings fitted and basically in final assembly now. Here are some piccies:

Piston - head clearance checking using 6 sheets of paper to get .024" (checked with micrometer). Cometic head gasket is .025".




Drive end of supercharger bolted up to allow measurement / fabrication of supercharger head bracket. Manifold in place to check clearance.

[loadswine]

I recognise that type of supercharger Stu. Is that going on the V6?

[muffdan]

Very interesting. Nice work! I like the positioning of the super charger.

[loadswine]

THe SC kit is designed for a Toyota too, its from a TRD kit. I agree it does look in a good position for the roadster.

[Anonymous]

I recognise that type of supercharger Stu. Is that going on the V6?

Right now I am trying to decide between two options 1) pull the v6 from my roadster and put this in its place, and 2) find an appropriate vehicle to put it in.

Was thinking about a Yaris just for a laugh but the guys on here persuaded me it was a bad idea so now not sure. I don't want to use another roadster because I already have one. Perhaps a Celica but it would be a bit crap with a few hundred hp through the front wheels. Might even consider a kit car for it if I could find one that could take the engine in a mid-engine configuration using the stock mr2 gearbox.

[custardavenger]

Good work there.

How is the SC supported? I was thinking about shaft driving my SC when I have the time to set it up.

[Anonymous]

The SC is going to be supported by a steel bracket using 4mm thick plates bolted to the s/c and to the coolant outlet face of the head (where there are 4-off 6mm bolt holes on the same level) connected together by 25mm bar. Currently WIP - hoping to be able to drop the plates off for manufacture in a day or two.

[spit]

Very neat.

Do you want this thread moving into the Performance forum?

[Anonymous]

Yeah. Why not! Go ahead and move it over Ste. Thanks.

[Mod]Thread Moved[/Mod]

[custardavenger]

The SC is going to be supported by a steel bracket using 4mm thick plates bolted to the s/c and to the coolant outlet face of the head (where there are 4-off 6mm bolt holes on the same level) connected together by 25mm bar. Currently WIP - hoping to be able to drop the plates off for manufacture in a day or two.

I look forward to the pics.

Another question. I thought that engine was built high compression? What sort of boost are you planning at max rpm? And what rev limit will you run?

[Anonymous]

Bloody hell it is pretty hard to get someone to make two small 4mm thick plate profiles at the moment.... Anyone want to offer their services?

I thought that engine was built high compression? What sort of boost are you planning at max rpm? And what rev limit will you run?

It is pretty high compression (11.5 CR) and the plan to reduce tendency to pre-ignition is this:

1) The engine has a super-tight squish area (.020") to minimise area exposed to the combustion front thus keeping temperature down
2) VVTi function will allow adjustment of the dynamic CR particularly at the high VE regions of the map  i.e. running the inlet cam retarted at low rpm + high load points (where it is normally advanced) so it blows charge back into the manifold.

The plan is to control boost by closed loop PWM of a VSV feeding a re-circ BOV and to use a rpm & load mapped boost table so that boost is lower in the high VE regions of the map. Then wind up boost at the top end of the map to compensate for the stage-II cams starting to drop off past 7300rpm. I am targeting boost around 12psi max to make 350ish bhp and topping out the engine at about 8000rpm.

[custardavenger]

Wow. Hope that all works out. I'll be watching with interest.

Don't have a huge amount of facilities to make stuff at the moment. I get a lot of stuff laser cut and that could probably get done for about £10. Let me know if your interested and I'll try and draw it up for you.

[Anonymous]

Really I am only building the engine because I can't think what else to do with the parts! Don't know what it will end up in yet! I am sure something suitable will come along in time...

Nice one about the cutting Custard. Thanks. That sounds like pretty decent pricing.

I will draw the plates up and post the files online. Is PDF ok or do they want DXF?

[custardavenger]

Thats cool. I liked the look of you're engine when you were selling it but the high compression put me off.

Dxf is best.

[Anonymous]

High compression just makes it more of a challenge to get big boost... But when you get it working it is just so much more satisfying...

My fabricator pulled through for me actually so no need of the plates from your manufacturer now. Thanks anyway though. Should pick them up on Monday and have the bracket tacked up that evening. Piccies to follow.

[AllanE]

Couple of questions:

1. Is that a Vortech supercharger?

2. Have you considered using an AC pump and condenser to cool the inlet air?
May be completely impractical in that it wouldn't be able to handle enough volume, but as your supercharger is on the back of the block and the AC pump sits on the front...
If it worked, you'd have the possibility of sub-ambient inlet air temp.s which would go someway to offsetting the relativly high CR.

I'll shut up now!

[Anonymous]

1. Yes

2. I thought about that but really it is complicated and I actually doubt if the thermodynamics work out all that well due to the extra load on the AC compressor, and the max heat transfer rate of the system. Sure it could be made to work but there are simpler solutions to getting this high cr to work with boost. Careful increase of boost (or less bypass in the recirc valve) as the cams top out around 7000rpm is when the real gains will be found.

[ariz]

hi sjspitz
I have seen a trd supercharger like this one on eb@y and I was wondering if buy it or not for my mr2 roadster
my engine is a stock 1zz, 1.8L with a CR of... 10,5:1 ? IIRC

do you think that this supercharger could be used on the stock 1zz engine? or is it too big for that displacement?
thank you

[tasc74]

Hi, the 1.93 looks like a very interesting option. My lump has died and your thread has got me thinking that this might be a good way of sorting the engine out and getting a few more ponies to play with.
fe questions tho:

1. By boring out the liners that much will it still be a reliable daily driver engine or is there a high risk of them cracking/ failing?
2. If i was to go this way with my own engine can anyone reccomend a decent machine shop to get this sort of work done in the london area?
3. What would be the rough cost to do this to my engine- are they over sized pistons with a better oil control ring design than the face lift version?
4 . what sort of power would it  put out if I just bored it out to 1.93 but kept everything else stock?
many thanks
tom

[Anonymous]

It is not a good way of sorting a dead engine out from the perspective of cost. You had better have deep pockets.

1. The bore seems to work ok provided it is done precisely.
2. Not in London (that I know of). It is an easy job for the machine shop to mess up so choose on capability rather than location - after all shipping is cheap.
3. Machining of block £350+vat at least, pistons £400 imported to uk + sleeves £100 imported to uk = £850 approx, add £100 for special cometic HG and you are at £950. I have a finished 1.93L engine sitting here for sale at £1500 (see sale section) and that has lots of other goodies on it as well.
4. Why on earth would you spend a grand + lots of other rebuild costs on this work and keep everything else stock? Don't bank on big hp returns with this approach, perhaps 8 - 14 hp gain. The cams and head will really hold it back. The lack of decent rods will limit rev range. Either do the whole job right or save your money for the time being.

[Anonymous]

A bit of progress to report; supercharger now mounted. I am wondering about gearbox clearance so does anyone have an idea from this piccies? This is now basically good to go (only the injectors left to fit really); should make it easier to sell the engine assy now that it has a fitted supercharger - even if the plumbing is still left to do, that is straight forward because all the metalwork is arranged and the oil drain is in place. If it doesn't sell then I will have to dump it at a mates place while I wait for a buyer... Or persuade him to get an Elise-S and swap out the stock 1zz...

Anyhow, enjoy!

[aaronjb]

I suspect that might be right about where the shifter assembly is.. which could prove a bit of a problem.