2j + 3s = Homebuilt Hybrid, My Motor Assembly pics

Since there's a little discussion around the topic of Altezza turbo motors, i thought I'd post up a few pics of my turbo motor for my 3sge powered Altezza. I'm pretty sure I'm not pioneering this at all, as surely someone else out there has done this previously. However I've not yet managed to find anyone to ask for information, so made a few mistakes a long the way (3sgte pistons anyone?). All i can hope is that this info serves as a bit of inspiration for someone else with their project or just simply shows that with a little bit of work there is another option than spending a mint on Toda Gear if you're clearly not after big power. (machining, rods and pistons cost me less than $1K and i bought new!)

Anyhow here's the detail: (all images are thumbnailed)


Block
Stock Altezza 3sge
Very Slightly Decked and Honed



Pistons
Pic 1 - Genuine Toyota 2JZGTE pistons (Same Bore and same Gudgen Pin size)
Pic 2 - Machined Skirt to clear 3SGE oil squirters, all evenly balanced. (Die Grinder Special
Rings - Genuine Toyota 2JZGTE (Provide Acceptable tolerances)




Conrods
Pic 1 - Genuine Toyota 3SGTE Conrods (Gen 3) Balanced End to End
Pic 2 - Gudgen Pin end machined for clearance inside 2J Piston (Die Grinder and Linisher special)
Pic 3 - Rod fitted to piston
Conrod bearings - Genuine Toyota 3SGTE

Crankshaft
Pic 1 - Genuine Toyota 3SGE (Altezza Gen)
Pic 2 - Counterweights machined to clear 2JZGTE and balanced (blue mark)
Main & Thrust bearings - Toyota Genuine




Assembly Pics
Pic 1 - Crank, oil squirters & Main Bearings fitted and mains torqued
Pic 2 - All Pistons & Rods in with conrod bearings fitted and torqued, stock head Gasket
Pic 3 - Deck Height - Piston is at TDC - Not even close to protruding
Pic 4 - Stock Head, sump, Windage tray and oil pan fitted.




That about it really, there isnt a huge amount of machining required over what you should normally do. Only exception was balancing, mainly the front pulley, bolt, crank, cambelt gear, flywheel, pressure plate, clutch and flywheel bolts thanks to the shaved crank. With these pistons( with their larger dish and a good deck height), with my block and head (all oem and unmachined other than minor decking of the block) and stock head gasket leave with a static compression ratio of 9.5:1 . Which i think will leave me with good off boost driveability with the and able to wind boost into it reliably.

I havent got the motor running with the turbo yet (mocking up intercooler and downpipe etc) but will be updating with results (might even put up a proper build thread) when it does get running, in the next couple of months all things being equal.

Cheers
Andrew

You make me so jealous

Just a question, why is it necessary to get the whole assembly balanced when shaving the crank?

I thought you could get away with just balancing the crank?

Could you get away with just taking the 2mm off the bottom of the piston's instead of the crank?

Great job and write up Andrew! Looking forward to see the results!

Decided what turbo your going to be using yet? Sticking to the HKS GT2871?

Oh and another question, the Gudgeon End of the rods kind of float left and right on the ST246 pistons I have here,

Why is there so much left to right play between the Piston and the Gudgeon End? It has about 2mm play each way

Because it is all a part of the same rotating mass. Think about it, you bolt the pulleys to the crank, and the flywheel and clutch to the crank. This all affects the balance. I’m of the opinion you should be balancing anyway to reduce internal engine loads and vibrations that put undue stress on components that eventually lead to a failure. Build it properly, build it to last.

Few reasons why I didn’t machine 2mm off the pistons. One is because it is easier to get right and less time consuming to shave the crank, rather than 8 sides of individual pistons. Two because there is a lovely coating there I wish to not damage any more than I have by grinding clearance for the oil squirters. And Three because it reduces the overall height of the piston which could lead to it being unstable in the bore when rotating. In short, its quicker and easier to get right.

Thanks mate. Have got an HKS GT-RS, which is basically a Garrett GT2871R modified by HKS (think ball bearing and slightly different wheels) For engine management I have an Apex-i PowerFC. Will see what happens, but I don’t forsee too many issues using the PowerFC. Plenty of options available if it doesn’t.

Need the clearances for heat expansion and movement throughout its motion due to it being a floating pin setup

Very nice Andrew!

I'm always impressed by people doing it themselves rather than buying bolt-on parts.

Cheers greeneyes, its great that toyota make so many compatible parts (even if some require only minor machining)

Figured i should update this since i've had it running.

Started up and ran fine, purrs like a kitten even, like it was meant to be.

After doing a large global pull of timing across the map (i am using the Ljetro power fc, so it has a very n/a base tune) , we took it out for some road tuning, mostly off to 1~2psi boost (thanks to adjustable actuator arm) at light load to make sure things were going well. which they were. Very smooth, very responsive. The low down torque was great.

Ok time for some higher load runs. Give it about 1/2 throttle. gets to just over 5500rpm and my mate with the knock headset yells at me to back the f**k out of the throttle. Just as i lift off and pull out of gear, a small pinging noise is heard, and the car shuts down completely.

The noise that was heard on the headset was apparently metal on metal. NOT good.

So ended up getting a flat tow back home (was tuning less than a km from my house) pushed it into the shed and decided to do a bit of a compression test. So whipped all coils out, and all plugs out. When i got to the plug on cylinder number 2, it was ultra tight and took ages to wind out. When i got it out, i knew i had found the problem



notice the lovely gouge mark across where the tip should be. Looks real like the edge of a valve to me. Cann the compression test. its obvious i've located the problem.

Whip the throttle body off, and i find this a whole heap of alloy shavings in the base of it (the coolant was what got in there when i pulled the lines to the throttlebody off)


Get the whole inlet off. heres a pic looking towards the inlet valves of number 2 cyl

well what was inlet valves on number 2, both heads are non existent. If i look down the inlets to the rest of the cylinders, everything is fine. hmmm weird.

So whip off the exhaust manifold, turbo and all other bits keeping the engine on, and this is what i find.



Number 2 bore is obviously where all the action happened. so heres a closeup on it.


Theres bits of valve sitting on top of the piston, bits of valveseat, all sort of shavings. Piston has taken a hammering, the bore is nicely scored. hard to tell what exactly has gone on other than merry hell has broken loose. Number 3 piston has taken a bit of a hammering too.

So lets have a look at the head. Dare i lift it up and see whats happened here. well the head looks to be fine, apart from number 2 cyl, which looks a little something like



top left you can see thats an exhaust valve head actually turned around and trying to make its way back out where the inlet valve used to live. It is wedged in there quite solidly. Suffice to say the head is toast.

To recap, damage sits something like:

2 x Piston
1 x Head
1 x Block
(possibly 1 rod, depends what else i find when i pull the block out and strip it down this weekend)

Now what im sure you are all wondering is how did this all happen? Well on closer inspection on the cylinders that survived mostly (i.e. 1&4) the piston shows signs of the valves just nicking the edge of the flycut, maybe .5mm at the absolute most. So clearly the failure is caused by piston hitting valve, this is obviously the noise that was heard through the headset.

Obviously at light throttle this wasnt a problem, as vvti wasnt advancing very much. But when the cam advances (it makes a large advance at around 5000rpm) is when this problem occours. There is no problem sans vvti advance, so at the end of the day the failure is mine, for not taking into account the extra timing advance that vvt-i brings during the measuring and mocking up stage of this build.

The obvious fix to this issue to allow the 2jz piston to be used, is to flycut the extra tiny amount to allow the valves to clear on full cam advance, so i am pretty confident these can still be used.

Obviously this sucks alot, but it is me who has made the mistake and it has cost me bigtime. I am very lucky that there was no damage to my turbo, as that would have pulled curtains on this project for good. So i'm just going to suck it up and wear it, coz theres nothing else i can do for now. If anyone has a spare block and or head complete for reasonable money, i'd like to hear from you, so i can get this build restarted.

As per the first post, i am posting this here in the hope that all reading can learn from this experience, not just me. As they say, smart people learn from their mistakes, but clever people learn from the mistakes of others.

Thanks for reading

Andrew

Argghh! My sympathies Andrew!

Still, build it better the next time! We spent at least one whole rally season blowing engines up as we learnt the maximum compression we could run a Datsun at.

We tested the valve contact by assembling the engine w/o a head gasket & turning by hand, several times actually as we tried it at max and min cam settings. Then the ehad gasket gives you a couple of mm safety gap for valve stretch & chain slack etc.

Thanks keith,

Thats what i did, but i fixed the head in place with some old headbolts, and put some playdough on the top of the piston around the valve pockets to make sure everything was ok, put all the timing gear on and timed it up, but didnt take into account that vvti puts some cam advance on it.

Yikes! Sorry to see & hear that Distrb!

Hope the build gets back on track for you soon.

wow looks like a bomb went off. so whats the reason behind the 2jZ pistons? stronger?

Bugger!

Was hoping to see this in Welly.

Very glad to hear your not throwing in the towel though!

you can see it when you come to welly, you'll just have to come to my house, and it'll be in 1001 pieces again

Yeah, gone to far to go back, just need to haul the rest of the motor out and strip down to get a full damage assessment. Hopefully i'll be knocking on your door within the next couple of days for some more bits.

Because they lower the compression from stock 11.5:1 to 9.5:1 for boost, and are capable of holding a reasonable amount of power.

http://www.trademe.co.nz/Trade-Me-Motors/C...n-241134246.htm

Cheap engine, blown headgasket... could use the block etc from it?

Sad to see this But makes an interesting read and a good tip for others.

Sorry to hear this bad news Andrew

Were you using the manual head with the titanium valves?
I have an auto head on my engine - they use standard valves so I didn't have to worry about them.
Only thing is there isn't as much lift from the cams.

I have a manual head in good condition sitting in storage - if you can't find another one. Its just missing one of the cam gears, and the shims from under the buckets.

Hope you can carry on with your project

Cheers Corey

Sorry to hear this Andrew, I'm sure with your passion for the project it'll come right.
Sure its money but as you say you're commented so has to be put down to a learning experience I guess.
Good luck with the rebuild.

sorry to here man let me know if you want an bits iv got the odd bit lieing around

Turbo_tezza - Yep, was using manual head. Valves were not something i was terribly concerned over, and they'd probably still be ok if it wasnt for some contact!

Thanks to the wellwishers and those who have offered parts etc. Will pull the rest of the motor out and strip it down this weekend which should hopefully allow me to build a more definitive shopping list of what stuff is needed to get up and running again.

watch this space

Several turbo 3sges including mine have had little problems with the valves now that I've heard about... but they tend to mostly handle it.

Final results for the damage report is in!

Dismantled the head. Only salvagable parts are the shims, collets, springs, cams and camgears. All valves are slightly bent thanks to contact with the pistons. Almost a throwaway.

Block is f**ked, split the sleeve on number 2 bore in 4 places, causing major damage to the parent bore to the point that 2 litres of water made it through into the oil galleries. Imagine my suprise when 7 litres of brown sludge filled up my drain tray. Also number 3 has some large gouges out of the cylinder wall. block is going to the scrappy

Number 2 piston is obviously f**ked. but also has a lovely cross sectional crack around 2/3rds of it. Number 3 piston has several large gouges out of the crown. Numbers 1 & 4 sustained some contact from the valves on both sides, but will be able to be reused. Have had them inspected, crack tested and measured and they are fine.

All rods have been inspected, crack tested, measured and balance checked, and they are fine. Same with the crankshaft.

All bearings except for number 5 main are like new. So will replace number 5 main. Will also do big end bearings again, as they are cheap for piece of mind.

Waterpump, thermostat, oil pump, cambelt and idlers were all brand new for that motor, are all still like new (obviously), so they'll all be reused.

So total damage is at:

1x complete head
2x pistons
1x block
1x pride
1x wallet

I'll be back.

Ouch

Hope you can get it sorted with out costing the earth.... its such an awesome project it would suck to have it ended before it really gets started