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Hardcore Night Warrior
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Discussion Starter #1 (Edited)
As encouraged by our lovely staff, here is the 2019 edition of the 7M vs JZ thread. It's been almost 10 years since the last major discussion unfolded. 10 years have passed, and where are we now with regards to pros, cons, tech, understanding. The last part is important, as the thread is to promote understanding. UNDERSTAND? Please post sources and cross references here. Paper trail, evidence, etc.

Input from me. The M series goes back from the mid-60s, and continued all the way up to 92. It's a dinosaur of an engine (SBCs are older, but we are all familiar with the prowess of the SBC) I think the Buick based Land Rover V8 is actually an older bag of bones than the M Series. Never the less, I digress! Stock for stock when one considers the strength of the M line versus both JZ lines, the M comes short. Stock internals from what I can recall have been pushed to 600hp 600 tq. Torque blows up breaks rods, so the rods can take that, or there abouts. JZ line? 800-1000 hp and 800 or so torque.


http://users.tpg.com.au/users/loats/technical/mhistory/images/mengines/3M01.jpg

There's the hassle of swapping in the JZ line in to the A70 chassis. Gone are the times of finding a round mount cross member for JZ swapping, Now, they're readily available conversion kits for that. I've seen quite a few pre-89 JZ swapped cars. Not an issue anymore. Engine tuning? Readily available are custom harnesses for JZ swapping, as well as schematics for the DIYer. Not an issue anymore.




Cost? Well, what you looking for? Fun street car? A “stock” 7m can take it, but at what power level it necessitates a MLS head gasket? Cometic gaskets can be found and ordered at your local O'Reilly. What is fun/a goal for you though? 300, 400, 500+ hp? I personally think ppl get caught up in the numbers game and have to have a minimum of 550 whp. It's a “luxury” GT car. Try and enjoy the car for what it is. Some cats don't know how much these cars were adored by car enthusiasts of the day. The Corvettes were a joke and “poorly” built. People swooned about how smooth the A70s were in the day. F-Bodies, Stangs, Vettes? Trash. You couldn't compare them at the time.

Fine, you want 600 hp from your 7M? Let's talk about engine builds then. Since you're down there, you might as well (and it's a sign of the times) go stand alone, ditch the AFM, get rid of the multi-plexer, go with LS based coil packs, go FFIM (retain your A/C!), upgrade the rods? Options for rods? Eagle rods and better. Turbo tech? Single turbo, custom manifold. Now available are cam upgrades. Yes, I know Quake has his well stated reservations of the quality of cams from BC, but they are available. Also, are regrinds, but those can be sketchy with being able to dial in timing spot on from what I've been reading from folks, but they are in fact available. Slowly there have been more available parts and retro-fits for the 7M. During this time, SP did offer a bolt on 61mm turbo, but I believe those are discontinued. Correct me if I'm wrong. Gone are the days of the regular 60-1 CT26. CT-26 upgrade goodies are available from Mamba, and there stuff seems to be getting more popular, and at a fair price too. It would be interesting seeing what a CT26 based car with modern updates could do. FFIM, upgraded ignition, speed density, maybe even ECU as well instead of piggy-backs. Afterall, we are asking 30 year old hardware, and software to do something it was really not intended to do. That's one thing folks have to consider, what was it that the car was doing then, what is possible now, and how do these work together?

Let's talk BHG. 10 years ago people were still talking about that the EGR was the cause of the BHG, or it was the head gasket not suitable for turbo applications, and that non-turbos didn't get BHG. All wrong. We know JDM non-egr cars get BHG, we know GE engines get BHG. I'm going to ruffle the old-guard here with this, but I personally believe the 7M's main cause (if not only) of BHG is a cooling related issue. It was to do with the blocks. 16ish years ago I started noticing things about the 7M. They more often than not, blew @ 6, 5, and 1. I'm not saying they didn't blow other places, but I'd see the pattern of blowing at the back, and at about 120k miles. Also, I know they blow at other mileages, and sometimes not at all. Very rare.

I found that the 5M, and 6M's are NOT plagued with BHG problems as the 7M. Do they get them, yes. I asked why? 5M and 7M share the same torque sequence and torque spec. 6M? Haven't confirmed, but I imagine it's the same, yet they do not blow like the 7Ms. Two things to consider? Is the gasket material different? Possible, is the grade of metal different, also possible. However, despite being the same series, there's an inherent problem. The 5 and 6M all have the coolant passage/ water jacket at the number 6 piston location free flowing, whereas the 7M block and head has been sealed off from the factory. I always thought back then it should've had provisions in the block and head for coolant flow, and now people are talking about the Zulu mod. Pg.58 http://www.oldwayrod.com/images/Felpro_torque.pdf

10 years later, Quake has done the head bolt reems. I think that's an excellent idea after all these heat cycles of the head not getting cooling as it should and now it's soft, and only gets deformed and loses clamping pressure, particularly with higher torque yields. The metal is soft now! I think the ideal situation in today's world would be a new head, reems?, drill out coolant passages, as well as the block with matching cooling passages, and still do 72 ft lbs :)

Speaking of head work. There are really tough head bolts and studs easily available from ARP.

Head work with porting and polishing? Correct me if I'm wrong, but there's very little material to remove from the 7M head, which results in minimal gains. That, or it's just poor combustion chamber design. Both?

Oiling provisions? There's still not a great alternative to the 7M's less than ideal oil pump. Remedies include shims, and dry sump. Lol. As far as I know there are no new in box higher oil volume and higher pressure pumps available in a wet sump application. I've seen a lot of scored camshaft lobes in my time hanging around.

Crankshafts? Pre-89 and 89 plus crankshafts can be used. Pre 89 crank has less counter weights, and therefore higher redline. However, considering that has been 30 years in advancement of metallurgy since then. I would think that being able to get a stronger yet still lighter rod set than stock is now available, and could therefore offset the added weight of the different crankshafts. As such, using the higher counter-weighted crankshaft in combination with possible NEW technology rods could offset use of the pre89 cranks in order to get higher RPM 7Ms, but still getting a smoother rotating assembly.



I couldn't find a cool 1jz shot, but this is how we are accustomed to seeing them. lol.



JZ? What can we say about the JZ that hasn't already been said and unequivocally known. Well, it's stouter period. It's more reliable considering design and age. More power stock, as well as more than can be attained with simple BPU stuff. You've gotta find a 1 or 2 jz to put in. You've got to get the proper wiring for the harness, the proper hardware for the installation, mounts, bellhousing. Ppl say 1jz is missing out on torque due to displacement and the higher strung nature of the 1JZ.Well, I say find a VVT-i 1JZ, bpu it, and squash that argument. Parts are harder to find? A bit of interchangeability with the 2JZ yes, but you wouldn't be able to get to your local parts store and grab something for the most part, yes?

2JZ VVT-i? VVT-i GTE and GE VVT-i from the U.S. Available GE VVT-is.

How we're accustomed to seeing ALL 2JZs. lol.



More cons? Apparently, the JZ heads don't flow to best that they could. Not, bad perse, but there is room for improvement. I can't really think of anything else “wrong” with the JZ. There's a lot wrong with the 7M that needs to be addressed. I can't really think of anything wrong the JZ family.

Personal input. I think a lot of it comes down to the hassle of swapping an engine, or the hassle of building an engine to try and bring it up to snuff and updating the engine while addressing its problems. The 7M has to play catch. JZs are essentially ready to go. In a sense it's easier. Personally, building it could be more expensive and certainly more of a hassle for a 7M depending on goals. I say more hassle if doing a full build that can support 600+hp and 600+ tq. Of course, if you just pay someone to do it all, then it's just down to money and not hassle :p

Other considerations? Keeping it the way it came argument. A70s came with 7Ms, yes, but as soon as you modify the 7M you're deviating from that argument of keeping it stock? Stock to a degree at any rate. Third gens also came with JZs, haha. That opens up the JZ argument and doing a 1 or 2 JZ as ok.

People like the 7M sound vs. JZ. Ok. Can't argue that. Preference. People say the 7M has more torque. Again, VVT-i. People are stubborn and like the underdog. I can't argue against that either.




 

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Being an owner of both platforms(2jzgte and 7mgte), hands down Money not being an issue, 2j wins. I never cared that the 7m came with the mk3. The swap kits are as direct as can be with places like drift motion etc.

420 whp, 450 ft/tq on twins at 18 PSI stock everything motor wise, 550 cc, 255 walbro, 3 inch exhaust with intercooler. Was a blast to drive and extremely reliable. Now on single, i wouldn't want to know what 700whp in a 7m would cost or take to build, and then contemplate reliability.

I think if you're content with 400WHP range stick with the 7M.

2019 i don't think the 2jz vs 7m debate will be as heated as previous years.
 

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7M-GTE:

I've had the Toyota OE headgasket @75ft-lbs over 450wtq on piggybacks. The primary game is avoiding detonation as that instantly kills a composite HG. Deleting EGR is a big help, doing it *correctly* by deleting the EGR cooler on the back of the head is critical. The Zooloo mod (aka Zulu mod) is also worthwhile but there's precious little hard data on that mod good or bad.

These days, with a simple IS300 coil pack swap and ECUMaster standalone I believe a MHG/ARP/Oil Filter Block Delete 7MGTE could easily crest 600whp/600wtq with minimal fuss so long as the turbo, IC, and fuel were properly addressed. I firmly believe a lot of historic failures on 7M-GTE's were not because of engine strength issues but were engine management issues. In particular, the old SOGI trick of setting the base CPS timing @ 14* BTDC instead of 10* tended to stack with piggybacks to make big problems. Yes, setting that at 14* makes a rather stark difference in throttle response and power when otherwise near-stock. Once piggybacks or 12+psi are involved, keep it at 10*. With a standalone, obviously, accurate cam/crank sync is the most important function of the CPS and timing adjustments should be made in the tune, not physically. Driftmotion offers a very good digital CPS rebuild suitable for standalones.

Oil system - the oil filter block is a pretty big culprit in oil pressure loss. Once upon a time, it was designed to prevent oil pressure spikes from causing issues with oil seals in the original CT26. But with age that threshold has dropped and the best thing you can do is eliminate it entirely and go to a proper full-flow thermostatically controlled oil cooler block and eliminate the stock cooler and filter block entirely. That combined with modestly shimming the oil pump and running 20w50 VR1 motor oil will go a long way in preventing rod knock.

1JZ/2JZ:

These engines have aged as well. 10 years ago those engines were relatively young and one could get away with minimal if any maintenance before swapping one in, and letting it eat.
But now a comprehensive maintenance package is strongly advised regardless of 7M, 1JZ, or 2JZ when starting a new swap or a new project. Plan the basics like seals, water pump, timing belt, belts, hoses, etc at the very least regardless of engine.

JZ's also aren't nearly as cheap as they once were. The days of $1500 non-vvti Aristo 2JZ-GTE's are long gone. When parts alone for a 2JZ-GTE swap easily crests $4-5k at the bare minimum, this means a 7M-GTE is more viable for moderate power levels, especially when a forged rods/pistons shortblock along with MHG, fuel system, and standalone can be reasonably done with the same 4-5k budget.

If one is simply looking for 400-450whp with maximum reliability, the 2JZ-GTE on a stock ECU is still the clear winner, but that is not nearly as cheap as it once was.
 

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What is the old saying ?
Oh, I remember, "They can take my 7M when they pry it from my cold, dead fingers".
It's like showing scars to your girl friend, showing how tough you are.

Anyway, agree with most everything you stated.
Laughed at the 'Zulu Mod' thing...
Years ago, we just called it 'drilling the missing hole in the block', LoLoL...

Yup, crap combustion design. Most modern 4-valve engine have the completely open chamber (JZ, RB, etc.),
and even Toyota supplied 7M heads for competition (Group-A) that didn't have all the shrouding of the valves.
Going to larger valves in a stock combustion chamber just makes things worse due to even less flow area between the valve and the wall of the combustion chamber.

Ports can use improvement due to production standards, especially around where the seats meat the casting.

I think some of the oiling issues can be addressed by ceramic coating the piston domes, and loosing the squirters, and going to a ball bearing turbo, which uses less oil volume.

But the pump is just too small.
Need someone with CNC equipment step up to the plate, and make a billet pump with larger gears.
Look in any hot rod catalogue, and you find billet pumps for damn near any pig-iron V8.
I was making an overdrive set-up, but new job limits me from doing any side jobs, and I would rather be able to buy new counter shafts to mod, than using the customer's old shaft. Maybe when I retire, and if Toyota makes the shafts available again....

But in the mean time, I think in lieu of a new billet pump, or overdrive, a good alternative would be an external pump (dry sump pump), using the stock pan. I've seen it done on other engines, and it eliminates all the hoses, and tank.
Of course you may finding room for it, like loosing the AC.

The one thing that bugs me about the 7M is the damn intake ports, the fact that the front 2 angle to the rear, the middle 2 are strait, and the rear 2 are angled forward. Makes life difficult when doing a custom manifold.

As far as 1JZs, I don't understand putting a smaller engine in a 3500 lb. car.
2JZ I understand, as it has a better bore/stroke ratio than the 7M, better combustion chamber design, and strait intake ports.
Not too sure about the oil pump design, as a lot of other engines withy the 'gerotor' style pumps have issues with them, and in industrial hydraulics, they do also, and pretty much have went away.

All in all, 26 years ago, when I popped my first head gasket, it probably would have been a better choice to buy a 2JZ.
Na...
Wouldn't have all the scars to show to the girls ;)
 

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Aussie guys are well into the 8's on stock block 1JZ engines.

Stock pistons. I absolutely love it.

Probably the most impressive feat I have yet to see out of any of these engines to date.
 

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Gordon you need to retire already and make more parts :)

Also 1JZ is boring, had one, sold it and bought a 7M. Likely only person in the world to ever do this, but there you go.
 

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Almost as fast as the HKS MkIII Supra was 20 years ago,
with a 7M....
You only have 1 more second to go, keep at it :)
Wait, did you just compare a stock engine with just camshafts against an entirely built 7M with dry sump, complete with reworked chambers in the cylinder head?

The 2JZ wins that category you're talking about.

1JZ is at 7.90 in the 1/4. Didn't the HKS run a 7.91?



As for boring, I've never been bored with any of my platforms I have built, whether it be a 1J or 2J based. Especially modded out. Most interested in the figures, not opinions on how a particular engine made you feel.
 

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Use loctite when putting your creeper together.

Other than this, I'm more into basil than sage.
 

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there seems to be more data now suggesting 5-600 whp is mechanically possible with stock 7m block / pistons /rods on a good tune, with a fuel system that can hold that tune

IMHO that is the change over the last decade. the 7m, with arp+mhg is stronger than the previous 400whp ppl would say back in the day

I am not saying the 7m is anywhere near as durable, x10 at that power level... just brute mechanical strength

well that and 2jz with the right sump setup is way more expensive now. don't hardly ever see a sc300, in any parts car / trashed ass condition for under 1G anymore. 10 years ago you could drive home a beater sc300 for $500

7m's come up on craigslist for under $500 all the time, thats still the same.

if you dont have deep pockets or mega hp ambitions, then yup,7m is for you. But you can't be a sally and will have to get dirty. your fingernails should be black and your shirts dirty on front and back.

what I like about the 7m is you can build it -OR- just shim the pump, arp + felpro it and send it. its cheep enough that if your motor blows its not like a huge investment (like forged motor getting the knock). with all that money saved on not buying forged/expensive oil setups/cams etc you can buy like 5 spare motors and have them ready to go. i call this the no fucks given approach, and (trust me) its really fun to drive the car with a cheep motor and spares at home. if your cool with 4-500 whp
 

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I pushed my stock 7M with a MLS HG to 511rwhp at 25psi with a little race gas on a 61mm turbo. That was stock block, stock head/cams, stock ECU with piggybacks. That car was a simple reliable setup that was very easy to tune. Ran a best time of 12.0 at 120mph with that setup.. I later went with a full built block/head/cams, standalone and it was not fun anymore.

As far as the 7M vs JZ. Pick what's easiest for you. But I would never give up 500cc's.
 

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I pushed my stock 7M with a MLS HG to 511rwhp at 25psi with a little race gas on a 61mm turbo. That was stock block, stock head/cams, stock ECU with piggybacks. That car was a simple reliable setup that was very easy to tune. Ran a best time of 12.0 at 120mph with that setup.. I later went with a full built block/head/cams, standalone and it was not fun anymore.

As far as the 7M vs JZ. Pick what's easiest for you. But I would never give up 500cc's.
What made it "not fun anymore"? I'm in the middle of building a 7M (forged internals, MHG, the works) and going standalone (had BHG, decided to do everything while I was in there anyway).
 

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Yo can I get a ride, I sold my MKIII years ago but I miss it. and the smell MadisonMKIII
 

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imo these days the largest hold up with the 7m is finding a head that isn't annealed to shit or have cam journals that look like sand was used as oil lol. if you have or find yourself a nice mk3 that hasn't been destroyed then building the original 7m is a viable option. other than i find it hard to just be coincidence that most 7m builds i've seen don't last long. either they rod knock or the head studs loosen blowing the headgasket(what happened to mine). my cars been swapped over to a 2jzge for a while now blown up a couple engines too but they're readily available. most usdm 2jzge have had a pretty good life auto came in luxury cars so the owners could afford to maintain but don't drive them like a nut bag. Can't say the same about 7m's since they only came in supras or even the 2jzgte and 1jzgte. the chance that those motors have been abused is very high compared to the 2jzge. people have got jdm engines where there's tons of sludge or rust on internals it's harder to find those mint swaps these days.

so my 2019 opinion is screw the 7mgte, the 1jzgte, AND the 2jzgte i'll take my 2jzge's allllllll day!
 

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What made it "not fun anymore"? I'm in the middle of building a 7M (forged internals, MHG, the works) and going standalone (had BHG, decided to do everything while I was in there anyway).
The main issue I had was the tuning with the AEM EMS. The 7M ignition system did not work well with the EMS causing a low rpm stumble that I could not get rid of. After I ditched the stand alone EMS and went back to the VPC, I could not get the car to idle with the BC264 cams unless I adjusted the throttle tensioner. The moral of the story is that I should have gone out of my way to find a good tuner.
 
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