Tuesday, September 21, 2010 - 12:39 am, by: Costa Tsimiklis(Driftshop)
Hey Guys,
I managed to get a cheap 2JZ GE that is in VGC in most ways and I decided to do my own 1.5J and get my head around the internet. bullsh.it that's on forums these days.
My goal is to document the conversion and come across problems with solutions with actual real info that people can use instead of bs.
So to kick this off, my current hands on research tells me that the following is needed for a successful 1.5JZ conversion on a GE block. GTE will be similar, with less work.
1JZ -> 1.5JZ conversion using a GE Block
GE vs GTE Facts: Pistons are the same design, but different crown shape. The top ring skirt is very similar in thickness to the GTE. Rods are the same as GTE Crank is the same as GTE There are NO oil squirters and who needs them anyway? Plenty of RB30s with decent pistons running 1000+ HP with no squirters. Interesting in theory and in practice and if you can afford to install them, good, but not vital for a high HP drag build. They will help with 25 laps at a track, but for a street squirt and club day (5 laps) no squirters should be fine.
1.5J requirements - parts you need of the 1JZ Fuel Damper Assembly for connection to your stock fuel rail and system in the soarer. Complete 1JZ head and manifolds 1JZ OIL Filter Assembly with water cooling - Bolt straight in and you get that nifty water/oil cooler 1JZ Water Pump Assembly and rear housing 1JZ rear pipe works that goes from pump to under the manifold for turbo and oil/water cooler and inlet mainfold 1JZ Crank Pully - its all Steel and you dont get as much of the same problems with the 2JZ one splitting because its alloy/steel hybrid. 1JZ Lower Timing Belt Crank Sprocket - Need this for the REF signal for the ECU. The GE runs are distributor to get its crank signal 2JZGTE Oil Pump - it has the hall effect sensor provision the above toothed wheel. You can use your 1JZ sensor. This will also allow you to clear the height for the timing case - no ugly gaps etc. 2JZ Serpentine Belt Tensioner - 1JZ is smaller - Need 2JZ for accurate tension. 1JZ Engine Mounts L/R (soarer) as they are different to Supra. 1JZ Oil sender near dip stick and fuel dampener (4 bolt thing) 1JZ Knock sensors *incomplete
1J head mod information for 2J.
The problem with the 1J head is that it has an offset OIL gallery inlet at Cylinder 6 factory. There is 3mm extra material cast into the block of the 1J to accommodate for this. The 2JZ does not have this extra 3mm and thus there may be issues with seal, as there is only 1mm sealing the block and 1J offset oil feed. Solution has been to weld the offset and drill an new hole and run a 2J gasket. I suppor this method as it is the correct way to do this.
Some have used 1J head gaskets with no mods, with success, but if it does get bent in install on that edge or if you miss with a tool during servicing and damage that protruding edge - you will get a major oil leak and can cook the head/motor from oil starvation. Pics below will show the detail I am talking about.
1JZ Meet 2JZ
2J Extra Deck height
1J - nearly flush with bell housing
2J GE Water Pump
1JZ Water Pump. Need Factory 2JZ Extension Pipe (OEM Toyota Part - ~$35)
2JZ GE NO Water/OIL COOLER
1JZ Water Oil Cooler - Bolts on!
Knock Sensor (Cyl 2 & 5)
Oil Level Sensor 2JZ GE
Oil Level Sensor 1JZ
Common Problem - Damaged Woodruff key for balance - Fix - Weld and Machine or recut a groove 180deg and re-mark balancer and weld hole. Cause - Backyarders not knowing how to tension up the balancer bolt. It MUST BE over 250 nm worth of torque. 323 nm is the factory manual spec. Super Cheap auto rattle guns - 80 NM at most. Apparently this happened in 10,000kms since the guy did the timing belt himself.
Damaged Key
2JZ GE Gasket on GE Bottom End, GE Oil Feed
2JZ Oil Feed on Block
1JZ Oil Feed - more material in the block for elongated feed +++ jpeg +++ 326973 +++ Upload +++
1JZ Gasket on 2J Block - Notice the overhang from missing material?
Overhang = bad
Costa Tsimiklis DieHard Victoria 386.2 rwkw Soon T51R or GT4094
Tuesday, September 21, 2010 - 12:49 am, by: Costa Tsimiklis(Driftshop)
Overhang = bad
2JZ GE Gasket on 1JZ - clearly shows how much material is missing from the 2JZ block.
2JZ head Oil Feed
1JZ Head Oil Feed - Offset to block oil feed from factory!
2JZ GE Combustion Chamber
1JZ GTE Combustion Chamber Bigger valves, maybe more CC than GE.
How to Kill a 1JZ - Never service it. The Aluminum RUSTED from galvanic corrosion, due to poor maintenance. Service your JZ and it will be fine! Dont service it - you will fu.ck it up like this one! This has got to be the worst case of head corrosion that I've seen. The rusted deposits in side the head is iron from the block.
The poor sod changed water pump, radiator, coolant and thermostat to solve the overheating issue..... problem is - engine is rusted through and cannot mechanically seal against the gasket - throw away head and get a reco one or 2nd hand 1JZ.
Tuesday, September 21, 2010 - 08:06 am, by: Matthew Sharpe(Madmatt)
Great posts! Yes getting the balancer bolt torqued up at home is a real problem - my toque wrench only goes to 180N/M! In the end I put a 1 meter extension on a breaker bar and put most of my weight into it, as 300N/M is approx 80KG at 1 meter. Seems to have been OK so far (90,000k/m and then 20,000k/m since balancer rubber failed)
Tuesday, September 21, 2010 - 01:37 pm, by: Mark Bryant(2jz_nat)
I'm interested in this build!keep posting some picks up as you go
Guy Moore-i believe you could use the ge sump,but there is no oil drain.with my 2jz sump the oil drain was there with 2 blank holes for the bolts and blank hole for the drain hole.I made a thread in the 2 holes and drilled the blank drain hole.Then a t3 turbo oil drain flange is the same size as the oil drain on the 2jz sump.used this.
The 1jz sump fits and would eaiser as it has a oil drain already.
sorry to hijack your thread costa,im thinking about doing this my self soon.
Costa Tsimiklis DieHard Victoria 386.2 rwkw Soon T51R or GT4094
Tuesday, September 21, 2010 - 05:14 pm, by: Costa Tsimiklis(Driftshop)
Use 1JZ Sump and Pickup for turbo oil drain. Oil turbo feed will need to be tapped from the filter/oil pressure switch. Some bundy tube will help with the routing of the lines.
Compression solved- Use a thicker gasket.
0.38mm head gasket thickness for 2JZ GE 10.0:1 compression
1.3mm head gasket thickness for 1JZ GTE 8.5:1
Some say running a 1.8mm or 2mm gasket will give you 8.5:1 on a 1.5JZ using a 2JZ GE block.
What's interesting, the 1JZ GTE uses a flat top piston, whereas the 2JZ GE is dished. I'll need to CC the pistons/deck to see the actual volume difference. If you were really game you could run 1JZ pistons in a 2JZ GE block. I may look into the viability of this as I will need to remove the crank to get the keyway recut so pistons will be removed to clean them up and remove the crud.
Tuesday, September 21, 2010 - 05:23 pm, by: Walter Gillmore(Cl33pa)
how many k's are on the crank that your going to plug weld and recut the harmonic balancer keyway?? ive done plenty of keyways for rb engines and diesel cranks. never a jz one... yet. does the jz have a crank driven oil pump such as the ones found on the rb's? if so i would dare say that the keyway for that if it exists will need to be done as well.
Tuesday, September 21, 2010 - 05:44 pm, by: Mark Bryant(2jz_nat)
I used the oil pressure sensor hole for my oil feed with a T piece.Another popular option is getting a union bolt for a is300 as it has a hole and thread for the sensor and just plug your oil feed in there. the soarer,supra 2jzge has a union bolt but no hole for a sensor/oil feed.
Tuesday, September 21, 2010 - 06:22 pm, by: Guy Moore(Thesoarerguy)
Costa there is a thread on toymods were they have measurements your chasing for the deck heights and compression ratio's with the difference in the thicker gaskets
Costa Tsimiklis DieHard Victoria 386.2 rwkw Soon T51R or GT4094
Tuesday, September 21, 2010 - 09:14 pm, by: Costa Tsimiklis(Driftshop)
Walter: 125kms. Engine is in VGC. Still has visible factory hone marks and NO ridge on the cylinder block. The crank was fu.cked due to a backyard mechanic using a super cheap auto rattle gun. Not enough torque + cyclic wear = chewed keyway in 10,000kms. Yep going to weld the hole, cut a new keyway 180deg on the other side and notch a new timing marker 180 deg on the balancer - this way the crank pully key is 100% strong again and no stuff ups
How much would you charge for my crank to be recut? I'll supply a good pulley and key Freight is going to hurt lol!
Guy: I've been looking for the thread but cant find it - any luck?
Tuesday, September 21, 2010 - 11:16 pm, by: Walter Gillmore(Cl33pa)
new workplace doesnt have a milling machine. so i cant do it sorry, but its a pretty basic job, just need and lpg or oxy for pre heating the crank before welding, and a heat blanket/ fire blanket to protect the rest of the crank and journals from spatter. let it cool on its own and a local machine shop can cut the keyway. shouldnt be anything ridiculous, price wise.
but what i used to do was really clean up the worn side of the keyway with a dremel, then get rid of all the oil by lettin the keyway soak in acetone or similar, and depending on the material of the crank either stick, mig or tig the worn side only, that way when it comes time to machine the keyway there is still the other face of the keyway to work off. saves money and risking getting the timing wrong by a few degrees. plus paying for the balancer to be re-notched and balanced.
cast iron cranks you'll need to use a stick welder with nickel rods.
cast steel cranks you can use mild steel mig wore, either in mig or tig.
and billet i prefer to tig.
takes a good hand to weld up just the one side of the keyway without flowing and ruining the other face. especially with cast iron.
Wednesday, September 22, 2010 - 08:35 am, by: Matthew Bell(Delxa)
We really need a Wiki or content based repository for awesome articles like this once they are completed. The forum is awesome for discussion but sometimes you just want the details without reading 50 mil comments to get there.
On topic though, this is very, very interesting info, Costa and I for one will be following it quite keenly as you make progress through the build. Keep up the great work!
Wednesday, September 22, 2010 - 10:46 pm, by: Costa Tsimiklis(Driftshop)
2JZ head is better than the 1JZ head. More cam options and valve options from aftermarket suppliers and its a proven 1600HP head with the correct modificdations
The only reason to do a 1.5J is if you have an existing 1J setup and just want a bolt on bottom end. Its more about convenience vs performance
Aaron: Totally agree there are benefits to it from an engineering stand point, but its not a deal breaker to making big power. Plenty of RB30s making 1200HP with no squirters that see more head and load + timing than a 600-700HP 1.5J using a GE block.
Interesting 3rd party info: ---------------------------------------- Head CC volumes: 1JZGTE=41.4 cc - need to be confirmed
2JZGE= 46 cc (alternate source that measured with a burette)
2JZGTE=47.8 cc - need to be confirmed
These are NOT EXACT measurements but are close. i dont have any micrometres at home so best i can do is verniers and straight edges etc. These are meanurements for 1jz-gte and 2jz-gte
1JZ dome thickness ~7.9mm 2JZ dome thickness ~9.2mm
1JZ Piston Above top ring thickness ~7.35mm Between top ring and #2 ~4.45mm Between 2nd and oil ring ~2.5mm
2JZ Piston Above top ring thickness ~7.5mm Between top ring and #2 ~4.5mm Between 2nd and oil ring ~2.6mm
So it would seem the 2jz piston is going to be stronger on all fronts. It also appears the 2jz piston has an actual machined finish on the top of the piston as opposed to the 1jz which appears to have casting marks on the top and not machine finished. ------------------------------
1JZ GTE vs 2JZ GTE Pistons
1JZ GTE Left 2JZ GTE Right
2JZ GE
2JZ GE
2JZ GE
2JZ GTE (TURBO) HUGE dish in comparison. Check out the shape and cutout depth.
My hypothesis: 1JZ had a smaller head CC due to the 2.5L bottom end. 2JZ has a larger head CC due to its 3L bottom end, in both GE and GTE - THIS is a huge factor in the combustion process and swirl design. A 2JZ head will flow more based on a larger head CC as well in a real dynamic combustion cycle (not on a flow bench).
1JZ also have 4 quench zones as the chamber is not circular - its square. Check it out in the pics above. This gives more efficient combustion for such a small capacity engine and perhaps why it responses to more mods than an RB25DET by comparison.
So lets look into this a bit more. 1JZ has a flat top piston with de-shrouded valve cutouts (notches on edge of piston), a 1.3mm gasket and a smaller CC combustion chamber than a 2JZ setup. Giving a 8.5:1 compression ratio (factory listed).
The 2JZ GE Pisons are different to the 2jZ GTE pistons, but are a similar shape. The 2JZ GE pistons have less dish and run a 0.38mm gasket with a 44.4cc head volume to give 10:1 compression.
I used this calculator ( http://www.csgnetwork.com/compcalc.html) with my guesstimates to get the right headgasket thickness for 8.5:1 comp ratio on a 1.5JZ using a GE bottom end.
Measurements are in mm and are slightly tweaked to give 10:1 compresion ratio here and there for comparison based on data.
2JZ GE 10:1 comp ratio. 86 Enter Cylinder Bore Size 86 Enter Piston Stroke Length 87 Enter Head Gasket Bore Diameter 0.38 Enter Compressed Head Gasket Thickness 44.4 Enter Combustion Chamber Volume In CCs -8 Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') 0.1524 Enter Piston Deck Clearance Negative If ABOVE Deck (Use '-') :
CR: 10:1
1.5JZ using 2JZ GE and thicker head gasket 86 Enter Cylinder Bore Size 86 Enter Piston Stroke Length 87 Enter Head Gasket Bore Diameter 2.5 Enter Compressed Head Gasket Thickness 41.2 Enter Combustion Chamber Volume In CCs -8 Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') 0.1524 Enter Piston Deck Clearance Negative If ABOVE Deck (Use '-') :
CR: 9.21:1 with 1.8mm CR: 9.06:1 with 2.0mm CR: 8.7:1 with 2.5mm CR: 8.35:1 with 3.0 mm
So a GE 1.5J is way differnt to a GTE 1.5J where you can get away with running a 1.6mm or 1.8mm gasket to bring you back down to 8.5:1 due to the deeper dished pistons.
Running a thicker gasket is not a great idea for low down power and fuel burn, but it will still make mega power and be drivable with the right turbo.
Costa Tsimiklis DieHard Victoria 386.2 rwkw Soon T51R or GT4094
I'll probably run a 2.5mm gasket for this experiment and have a conservative timing map in the top end. If this was a dedicated E85 only car, I would run 9.0:1 compression ratio with a 2.0mm gasket!
Just too add, this is a SUPER BUDGET BUILD. I'm trying to keep it all under 1000-1500 for parts alone. I've had good success with budget experiments and I like to showcase that you do not need to spend $8,000 on a 2JZ bottom end combo to get some serious power with decent reliability.
Running a 2.5mm thick head gasket is very unorthodox from an engine building perspective as it does away with the squish/quench zones and theory, however, I am hoping that the 4 quench zones will compensate for this effect compared to a 2JZ what only has 2 and recuperate some of this effect with the smaller CC 1JZ head.
If you want to a great 1.5J, use a GTE bottom end, but you might as well use a whole 2JZGTE anyway as you will get better head flow and less screwing around, but this may cost you 2.5-3k just for the motor.
I am also contemplating re-using the 2JZ GE head bolts as they have not been re-torqued before and my research indicates that they can be re-used, but it is not recommended due to factory tolerances and variance amongst bolts. Running an ARP stud kit will cost around $250 but I do not think it is vital to do so.
Costa Tsimiklis DieHard Victoria 386.2 rwkw Soon T51R or GT4094
Thursday, September 23, 2010 - 04:13 pm, by: Costa Tsimiklis(Driftshop)
2JZGE vs 1JZ GTE Valve Size
2JZ GE Inlet - 33.5mm Length: 98.70mm
Exhaust - 29mm Length: 99.30mm
1JZ GTE - 32mm Length: 97.60mm
Exhaust - 30mm Length: 98.31mm
Hypothesis - There is enough room on the 1JZ head to fit The 2JZ GE 33.5mm valves. the 1mm can be ground off the 2JZ GE valves and then re-shimmed for the correct clearance.
All valve stem diameters are 5.94mm too!
Another interesting thought would be to check the buckets on the 2JZ and see if they fit the 1JZ. Maybe the buckets are 1mm undersized.
Pics etc will be uploaded later on tonight/tomorrow
Costa Tsimiklis Goo Roo Victoria 386.2 rwkw Soon T51R or GT4094