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First time building a 7mgte - What am I missing?

15K views 62 replies 18 participants last post by  IdahoDoug 
#1 · (Edited)
Hi everyone! I am getting ready to pull the engine out of my 91 in order to fix the head gasket and reseal the engine. While it's out, I figured now would be an excellent time to upgrade some things to prepare for bigger horsepower in the future. I already have a turbo back 3" exhaust. Note that I'm not interested in anything external at the moment, since the stuff I'm already doing is maxing out my budget. I can add things like a bigger turbo later on. Below is the list of things I'm already planning on doing, is there anything else I should be doing while I have the engine out anyway?

  • All new seals.
  • All new coolant hoses.
  • New oil pump & oil squirters.
  • AZ Performance hardline.
  • Technico 7M Aux Shaft.
  • Resurface Head & Block.
  • MLS Head Gasket - Cometic 1.9mm x 84mm bore.
  • ARP Head Studs (using ARP lube, torqued to 90 ft-lbs).
  • Bosch 550 injectors.
  • Tweak'd Wiring Harness.
  • ECUMaster Black.
  • ACT HD Street / Strip Clutch Kit.
  • OEM Pressure Plate Bolts.
  • Resurfaced OEM Flywheel.
  • ARP Flywheel Bolts.
  • Denso TT Fuel Pump (no 12V mod).
  • New Starter (since they're a pain to replace).
  • Aeromotive AFPR Kit.
  • Driftmotion Digital CPS V2 Upgrade.
  • Fornari Racing CPS Delete Kit.
  • ATI 918525 Damper Pulley.
  • Custom 7M ATI Pulley Bolt.
  • ARP Inserts (200-8574) (finally an answer to the 7m head gasket issue?).
  • Zulu cooling mod.
  • Wiseco Pistons / Eagle Rods (83.5mm 9.0:1).
  • Balanced the flywheel / crank / pistons / rods / damper.
Just for reference, the above list costs about $6,800.00 BEFORE any labor goes into the car. My machine shop is charging me $2,200.00 in labor to do the work. This kind of build ain't cheap!

EDIT: I'm keeping the list above updated as I change my mind so I have an easy to find list and people can reference my current list before making comments.

Build Album: Supra Engine Rebuild 2019
 
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#7 ·
If you are sticking with the stock CPS, I'd suggest checking the seals and the condition of the wires. Driftmotion sells a rebuild kit that has a new seal and bearing.

Are you rebuilding the engine completely or just doing seals? Rings, bearings, timing belt and tensioner, valve seals, check valve clearance. If it's apart anyways, I'd put in a Technico oil pump bearing retainer plate. What condition is the waterpump? For exterior to the engine, check the condition of the coolant hoses that bolt to the block, those 90 degree bends are a lot easier to replace with the motor out of the car.

With the engine out, now is the time to look at the power steering. Is the rack good? You can upgrade the rack mounts to poly, change the lines (Driftmotion sells braided lines), etc.

Also, clean the engine bay.
 
#9 ·
I am sticking with the stock CPS. Good point!

I'm debating doing rings / bearings. The engine seems fine besides BHG symptoms, so I think the ones that are there are fine, but while it's apart anyway that might be a good idea.
Timing belt and tensioner, valve seals and a valve job will definitely be done.
I'll look into that oil pump plate.
Water pump has maybe 5k on it, but I have a new one as well. Will probably keep the existing one if it looks good.
Good point about the coolant hoses. I didn't put them on the list, but I will definitely be replacing all the factory hoses.

I do plan on checking out things like the steering system as I get to them, and the engine bay cleanup is absolutely 100% going to happen :) I don't want to be embarrassed to open my hood anymore!
 
#14 ·
I was actually just about to post a thread like this. Curious about the Tweak'd Wiring Harness you mentioned. I couldn't find it for the 7M-GTE on their site, is that something they offer offline?

Driftmotion offers an upgraded oil pump that I've seen recommended here before - https://www.driftmotion.com/Driftmotion-7M-Upgraded-Oil-Pump-p/dm1072.htm

I also have a strong running stock 7M-GTE right now but it's just about to hit 160k which leads me in the direction Enraged mentioned about adding rings and bearings to the mix since I'll have it open.
 
#15 ·
Curious about the Tweak'd Wiring Harness you mentioned. I couldn't find it for the 7M-GTE on their site, is that something they offer offline?
You have to contact them since they do not list it and you need to send in your core for them to rebuild. Someone else on SM who recently had their 7m harness built from them did not like the job they did. I would have used Yotaconnectors for a harness rebuild since it starts at $500 plus they have tons of new connectors they change out but I ended up making my own harness.

https://www.yotaconnectors.com/product-p/yc-7mhar.htm
 
#20 ·
Hi everyone! I am getting ready to pull the engine out of my 91 in order to fix the head gasket and reseal the engine. While it's out, I figured now would be an excellent time to upgrade some things to prepare for bigger horsepower in the future. I already have a turbo back 3" exhaust. Note that I'm not interested in anything external at the moment, since the stuff I'm already doing is maxing out my budget. I can add things like a bigger turbo later on. Below is the list of things I'm already planning on doing, is there anything else I should be doing while I have the engine out anyway?

  • All new seals.
  • New oil pump & oil squirters.
  • Resurface Head & Block.
  • MLS Head Gasket (Recommendations)?
  • ARP Head Studs.
  • Bosch 550 injectors.
  • Tweak'd Wiring Harness.
  • ECUMaster Black.
  • New Clutch (Recommendations)?
  • Resurfaced Flywheel.
  • 12V Fuel Pump Mod.
  • 460 / Denso TT Fuel Pump.
  • New Starter (since they're a pain to replace).
  • AFPR (Recommendations)?
  • Driftmotion Digital CPS V2 Upgrade
I am so fucking pumped to see so many 7M-GTE rebuild/restoration threads! :beer:

When replacing the oil pump, read up on shimming the relief valve a bit and also read up on bending the oil pickup to be closer to the bottom of the pan. Inspect the oil pump drive gear because I've seen them crack and fail - typically on the 'spokes' of the gear.
Personally I have found the oil squirters to be of dubious value for most street builds - you're stealing oil from bearings to dump piston heat into them, and this is a benefit from an OE perspective because they need to ensure the engine has a chance to survive when trophy wife Debra fills that car with 86 and merges onto a freeway in 100*F weather.
If you're building a car that'll see extensive road race track days/long ass highway pulls etc, and you're running a good, ducted oil cooler setup and monitor oil temps, there's a good argument to keep them.

What Elibutton said was also 100% on-the-money about removing the factory oil relief valve and the partial-flow oil cooler setup - remove that whole oil filter housing from the side of the block and go to a 7M-GE style union bolt and a full-flow oil cooler on a thermostatic sandwich plate. That is a really good idea even if you're basically doing a stock build.

The ye olde HKS 1.2mm bead works great, there's also a Cometic 0.51" (about 1.2mm) with an 84mm bore that works a bit better with a stock bore vs the HKS's 86mm bore. The Cometics had an issue with rivets that hold the MLS layers together being in places that interfered with block/head sealing, so be mindful of rivet placement if you're going with the cometic and trim/drill out rivets as needed.

Personally I'd just go with the HKS HG and call it a day - it'll hold anything you can do on the stock pistons and then some.

Injectors - 550's are pointless with a stock CT26 turbo and the only benefit to old school EV1 style Bosch 550's is how they play well with the stock ECU and OG piggybacks. Since you're going to a ECUmaster which as far as I know only supports high imp injectors and requires a resistor pack to run low imp, I'd just get a set of modern EV14 pattern injectors of the appropriate size for your fuel and power level desired when the time comes - yes they are that much better. Get a set of EV14 pattern 725cc or 1000cc or similar for a non-vvti 2JZ-GE as that'll have the same injector length and 11mm feed used by the 7M-GTE, and it's a lot easier to find listings and options for the 2JZ-GE these days. You'll only use a fart's worth of their available duty cycle on the stock CT26 turbo but at least your base tuning will be that much closer to what you need when it's time to turn things up. This saves tuning time and also permits you to make tuning changes for drive-ability and environmental changes that'll carry over to your bigger turbo setup etc.

With the Walbro 460 pump, make sure you run an AFPR (the Aeromotive recommendation is proven, I've also had good luck with Fuellab regulators too) and run a larger return line that eliminates the 'j tube'. The J-tube has a engineered restriction in case of FPR failure and you'll have crazy high fuel pressures at idle and low load with a Walbro 460 if that's not eliminated. Driftmotion sells a very nice AFPR install kit that basically does all the hard work there for you.
If you opt for the TT Supra pump instead, I would leave the 10/12v switching in place. Walbros tend to make a lot of noise when fed less than 12v but that is not the case with the Denso pumps. I have never seen a 12v mod fix anything or improve anything unless it was bypassing a faulty fuel pump ECU, or someone installed a 255 and wanted to reduce the 'Walbro whine' from the 10v operation. There is no other major benefit performance-wise or otherwise. The TT Supra pumps are silent compared to the Walbros and will completely support ~450-500whp on pump gas as a single pump.

New clutch - do NOT get anything with an unsprung hub. Personally I have run ACT pressure plates with stock clutch discs to ~400-450wtq on several different setups and while the pedal pressure is a bit higher the engagement & slip-ability is very nice and easy to drive, especially with the stock flywheel. As an interim that matches your stock turbo, there's no need for anything more. Use new flywheel bolts!

With the V2 CPS, and the ECU master, consider ditching the stock 7M-GTE coils and going to IS300 coils instead and having your wiring harness made to suit those. They are hotter and support significantly more HP than most tired old 7M-GTE coils do. Doing this now will ensure reduced growing pains in the future when you build an engine and go for bigger HP, much like going for better injectors now instead of wasting tuning time with older, smaller injectors that will not support your end goals.

Speaking of which - what's your intended HP goal? If it's ~400whp or less I would honestly skip the standalone entirely.

Keep us posted on your progress! :beer:
 
#23 ·
Thanks! That's a lot of information, which I'll go over carefully when I'm not at work!

I don't really have a HP end goal, I tend to just modify things as they break. Since the HG is toast and it leaks oil, I'm going to pull it and do everything right the first time so I don't have to take it out again for many many years. Eventually, it would be nice to hit 500WHP, but that's many years down the road.

I've already ordered the ECU and wiring harness (although they may not have started building it yet, so I might be able to make modifications). I currently have them making it for Bosch High Imp injectors, which I figured would allow me to run 550s for now and upgrade easily to larger Bosch injectors later on if desired.

I'll definitely keep you guys posted!
 
#26 ·
If you're going to use ARP studs with nuts torqued to 90 foot pounds, then it's helpful to have a very thin wall 14 mm deep well socket from craftsman because its a tight fit. Make measurements (or have the machine shop) of the head and block thicknesses after its cut in order to decide which thickness of metal head gasket you're going to use. You'll want to add that metal back to OEM specifications. 0.040" = 1 mm. The Surfaces need to be very polished in order to use a stacked metal head gasket. I went with a flat metal shim gasket on top of the block sprayed with Permatex copper seal and a standard Toyota head gasket on top of that. I'm not over boosting above stock. You can order shim gaskets in various thicknesses from: SILVER-SEAL.COM
 
#29 ·
877mgte

I read the entire thread. I am saying this out loud here as you are rebuilding the engine and regardless of power, needs to be addressed (and I have not seen it mentioned).

Do not reuse the OEM damper. Reason why, Age alone has deteriorated the rubber to almost a purely solid brittle state that is leading to separation of the outer ring to the hub. Budget for the ATI damper and avoid long term issues. :)
 
#35 · (Edited)
Another vote for Yotaconnectors! Ron has been super helpful in getting my harness rebuilt for my 7m build. Good to see another local guy on here (Da Kine Guy)!

I'm also knee deep in a 7m rebuild would like to share a few of my own experiences/woes:

- Replace the oil squirters if you plan on disassembling it anyway, good cheap insurance. Get a new oil pump and replace the horrid crush bent oil feed line with one from ARZ performance.
- Some may agree/disagree, but I am switching to a full flow oil cooling system (switched to the GE oil filter block and added an aftermarket thermostat) and got rid of the stock GTE pressure based oil filter block.

I think as long as the HG and oiling isssues are addressed, the 7m can be a pretty reliable platform!
 
#41 ·
First, take it to another machine shop and see what they say. I've seen maybe two R154 flywheels ever that were genuinely too fucked to save.

Find another stock one if at all possible. If you MUST go lightweight, make sure it's an all-steel one do not use one of the aluminum segmented pieces of shit like Fidanza.
 
#44 ·
Nice to see another 7M build. I'm doing a hone/rings/bearings just to start off with a solid platform and because it's reasonable money. Only 124k on it but still...

So one thing I did not see on your list is a radiator. What are you thinking/planning there? I am planning stock as my engine will be unmodified, but you'll be putting out some heat!
 
#45 ·
On top of a good radiator also I suggest you upgrade the fan clutch with one from a 03 Tacoma with the v6. I recently did mine and it is a small hurricane with all that air moving when I first start the Supra now lol.
 
#48 ·
Dirty6,

I don't understand the comment about replacing the oil squirters. These are a completely pedestrian item like an oil pan baffle as another example, that is a lifetime part and I cannot see them providing any trouble. Ever. Were you thinking of another bit, perhaps?
 
#50 ·
It's actually the squirter bolts. They contain a small pressure spring, which can wear out and cause oil pressure issues from what I've heard. I got an OEM set for around $60. I think that's pretty cheap insurance considering the fact that I intend for this engine to last an extremely long time.
 
#53 ·
Just dropped off a bunch of parts at the machine shop. He asked if I wanted to balance the crank / rods / pistons for an extra $300, but said it usually wasn't necessary with these engines. Anyone here have an opinion on balancing during a rebuild?
 
#54 ·
I don't have much experience with it, but an extra $300 isn't much in the grand scheme. I'd do it.

When I do my engine build I plan on having everything balanced/blueprinted (I think those mean the same in this context, but I could be wrong).
 
#56 ·
If you plan to turn higher RPM, you may want them to match the balance factor to the goal rpm range.
The higher the rpm, the greater percentage.
This means either more weight on the counterweights, or less weight on the piston/rod/pin side.

The more modern crank balancers will actually display this info on the control screen.
The balance factor is determined by the weight of the lower half of the rod, and rod bearing added to a percentage of the upper rod, pin, piston, and rings.
Shops that do a lot of race engines will know the percentage numbers for different rpm ranges.
 
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