91Supra313;1931050 said:
Well I meant the JDM engine if my block is shot. I got the car for a grand and I was gonna take out a 3,000 loan to get her on the road
How reliable is the 7mgte?
- Thread starter jcarlson73
- Start date
Well I meant the JDM engine if my block is shot. I got the car for a grand and I was gonna take out a 3,000 loan to get her on the road
hm... well I've owned lots of 7m's that never had a BHG... of course they were all properly assembled (not using inadequate factory torque specs on the head)S.A. supra;1930968 said:
I've had one w/ a BHG, but it had a BHG before I even got it.
so all in all, it's safe to say that the 7m can be problematic, but like any engine if it is properly assembled and taken care of, you really shouldn't have any issues.
I daily drove mine for a couple of years in my super red '89. Only thing that broke was my clutch which exploded (poor quality) didn't have $ for OE, so I cheaped out, bad move.
@ OP you aleady started a thread asking for advice on JDM engines, I would have to flat out tell you to go back and read over the replies, the basic info you need is there, I don't know why you're still asking about it...
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Reliable enough to be daily driven for the past 3 years.
I've had 2 electronics fail (NSS & TPS), but no engine issues!
Happy fluids make for a happy engine, keep up with maintenance.
Finally, something we can agree on. :bigthumb:
I've had 2 electronics fail (NSS & TPS), but no engine issues!
Happy fluids make for a happy engine, keep up with maintenance.
jetjock;1930971 said:
Finally, something we can agree on. :bigthumb:
These threads remind me of the 6.0 powerstroke threads. They had egr problems from the factory and would blow a headgasket . About 80% of the engines did this at least once. Very east fix it was a egr delete kit, arp head studs and oem hg. Then the truck would go for 300k plus miles pushing 30lbs of boost. Everyone who doesn't have one shots on them because of there "factory reliability" they remind me of a 7m... Your maintenance has to be up to par in both engines and they need be slightly fixed from the factory and they will never fail you.
Everyone will shit on the 7m because of headgasket. 1jz and 2jz guys the most but the 7m is the reason why they have mhg... They should be thanking us
Everyone will shit on the 7m because of headgasket. 1jz and 2jz guys the most but the 7m is the reason why they have mhg... They should be thanking us
Insidious Surmiser;1931071 said:
Well I mentioned what I was thinking about doing on this thread. But in general I like to get as many viewpoints as possible in the JDM since its a very shady business.
Here's a little more info:
The 7M is essentially a very good design with a few caveats.
The good stuff: First and foremost, it's an inline 6. That gives you 7 maincaps for 6 cylinders. That's a well supported crank. The inline 6 is an inherently well balanced design, meaning less stress on the rotating assembly as compared to other designs. One comparison would be against an inline 6 which is not as inherently balanced and only gives you 4 maincaps for 6 cylinders. The oil system is a high volume, low resistance system which works well. The tolerances, machining and balance are all very high end due to this being a product of mid 1980's Toyota technology.
The caveats: The bore is smaller than the stroke, so this (long stroke) motor doesn't take well to high revs as well as a square (2jz) or short stroke (1jz) design. This is a mixed material motor with an iron block and an aluminum head. This means you've got different thermal expansion rates between these two surfaces that are mated together. The bores are so close on a 7M that the cylinders are nearly siamese and there's very little gasket material between them. The inline 6 design unfortunately forces an extremely long cylinder head. You couple these last few factors together and you've got a design that puts a LOT of stress on the head gasket. Add in a little extra boost, an unmetered air leak, the wrong fuel, poorly done modifications or a failure to address small issues before they cause detonation and you're going to put more stress on that gasket than it can handle.
As mentioned, the factory torque spec for the head bolts was long ago determined to be a little bit too soft. Torquing them to the appropriate new values fixes this issue. Upgrading to a metal head gasket with the proper prep of the mating surfaces adds more insurance. High quality fasteners add a little more.
So with all that said, yes this can be a reliable motor, it's an inherently good design with a few weak spots. The primary being that the head gasket doesn't tolerate detonation well. In the end, as I've said hundreds of times at this point; the weak link in the MKIII is usually the owner. If you don't use your head, perform poorly thought out mods, cheap out or skip maintenance and generally act like a complete bonehead, the 7M will hand you a well deserved world of hurt. Only you can decide if you're going to be the weak link, or one of the stronger ones.
If you can use your head, do the correct modifications in the correct order, perform maintenance as needed and pay attention to details, you'll be fine. However you had better be ready to spend money, this isn't a cheap endeavour and trying to do it "on the cheap" just about always ends in failure.
The 7M is essentially a very good design with a few caveats.
The good stuff: First and foremost, it's an inline 6. That gives you 7 maincaps for 6 cylinders. That's a well supported crank. The inline 6 is an inherently well balanced design, meaning less stress on the rotating assembly as compared to other designs. One comparison would be against an inline 6 which is not as inherently balanced and only gives you 4 maincaps for 6 cylinders. The oil system is a high volume, low resistance system which works well. The tolerances, machining and balance are all very high end due to this being a product of mid 1980's Toyota technology.
The caveats: The bore is smaller than the stroke, so this (long stroke) motor doesn't take well to high revs as well as a square (2jz) or short stroke (1jz) design. This is a mixed material motor with an iron block and an aluminum head. This means you've got different thermal expansion rates between these two surfaces that are mated together. The bores are so close on a 7M that the cylinders are nearly siamese and there's very little gasket material between them. The inline 6 design unfortunately forces an extremely long cylinder head. You couple these last few factors together and you've got a design that puts a LOT of stress on the head gasket. Add in a little extra boost, an unmetered air leak, the wrong fuel, poorly done modifications or a failure to address small issues before they cause detonation and you're going to put more stress on that gasket than it can handle.
As mentioned, the factory torque spec for the head bolts was long ago determined to be a little bit too soft. Torquing them to the appropriate new values fixes this issue. Upgrading to a metal head gasket with the proper prep of the mating surfaces adds more insurance. High quality fasteners add a little more.
So with all that said, yes this can be a reliable motor, it's an inherently good design with a few weak spots. The primary being that the head gasket doesn't tolerate detonation well. In the end, as I've said hundreds of times at this point; the weak link in the MKIII is usually the owner. If you don't use your head, perform poorly thought out mods, cheap out or skip maintenance and generally act like a complete bonehead, the 7M will hand you a well deserved world of hurt. Only you can decide if you're going to be the weak link, or one of the stronger ones.
If you can use your head, do the correct modifications in the correct order, perform maintenance as needed and pay attention to details, you'll be fine. However you had better be ready to spend money, this isn't a cheap endeavour and trying to do it "on the cheap" just about always ends in failure.
You have mentioned that you are short on money, concerned about this car becoming a money pit, and you are taking out a loan to fix it.
DO NOT DO THIS!
These cars can be great, fun, and reliable, but the road to get one there, especially one that isn't currently running, is long and expensive.
-AM3
DO NOT DO THIS!
These cars can be great, fun, and reliable, but the road to get one there, especially one that isn't currently running, is long and expensive.
-AM3
I had over half a million kilometers on my 7M-GE. The guy who bought it from me put in a new timing belt and valve stem seals, and dropped it into a Mk2. Factory head gasket, factory head bolts, torqued to 72 ft-lbs.
During the time that I've been driving a 7M powered Supra (About 14 years), I've had 4 blown head gaskets. Not one of them was a 7M. 3 engines spun bearings and developed knock. One of them was a 7M. One cracked something and died a horrible death. (My wife is very hard on cars, I'm not sure why, but she's NOT driving my Supra.
)
I put a lot of kilometers on the 7M that spun a bearing. I got the engine with a BHG, and didn't replace the bearings. I put in a gasket set, including an OEM head gasket held together with ARP studs, but never touched the bottom end. The years of sitting took its toll and a couple years later, the bearings were gone. They actually went for longer than I think that they should have.
It is my opinion that the 7M gets an undeserved bad reputation. I believe that it is no worse for blown head gaskets than many other engines of a similar vintage with a cast iron block and aluminum head, and by my own experience, is actually far less likely to have a blown head gasket than many other makes' engines. (One of the engines that I mention above had it's SECOND blown head gasket (MHG, properly torqued, head warped) by the time that it's total mileage was at about what I put on my Supra (on average at the time) in 2 years.
I believe that the 7M, like any motor driven with high performance expectations is an unforgiving bitch who will snap at you for the slightest lack of attention to detail. The A70 chassis seems to conspire to get her to bite you, too.
For every "Oh look I installed a 1JZ/2JZ/1UZ/SB V8 and it solved my problem" I'll look at the build thread, and it includes a new radiator, water pumps, fuel injectors, usually turbos and general support parts making the whole build like a brand new car. Think about it. If the 7M were blowing head gaskets while crazy while these cars were still under warranty, (And had new radiators, pumps, turbos and general support parts) Toyota WOULD HAVE done something, particularly if the '87-'88 ones were doing so by 1990, while they were still building them new. The Supra was their flagship sports car after all, and at the time, they were still serious about it.
Is the JZ block tougher? Probably. Is it tough enough to survive 20 years of minimal maintenance? I wouldn't bet on it.
During the time that I've been driving a 7M powered Supra (About 14 years), I've had 4 blown head gaskets. Not one of them was a 7M. 3 engines spun bearings and developed knock. One of them was a 7M. One cracked something and died a horrible death. (My wife is very hard on cars, I'm not sure why, but she's NOT driving my Supra.
)I put a lot of kilometers on the 7M that spun a bearing. I got the engine with a BHG, and didn't replace the bearings. I put in a gasket set, including an OEM head gasket held together with ARP studs, but never touched the bottom end. The years of sitting took its toll and a couple years later, the bearings were gone. They actually went for longer than I think that they should have.
It is my opinion that the 7M gets an undeserved bad reputation. I believe that it is no worse for blown head gaskets than many other engines of a similar vintage with a cast iron block and aluminum head, and by my own experience, is actually far less likely to have a blown head gasket than many other makes' engines. (One of the engines that I mention above had it's SECOND blown head gasket (MHG, properly torqued, head warped) by the time that it's total mileage was at about what I put on my Supra (on average at the time) in 2 years.
I believe that the 7M, like any motor driven with high performance expectations is an unforgiving bitch who will snap at you for the slightest lack of attention to detail. The A70 chassis seems to conspire to get her to bite you, too.
For every "Oh look I installed a 1JZ/2JZ/1UZ/SB V8 and it solved my problem" I'll look at the build thread, and it includes a new radiator, water pumps, fuel injectors, usually turbos and general support parts making the whole build like a brand new car. Think about it. If the 7M were blowing head gaskets while crazy while these cars were still under warranty, (And had new radiators, pumps, turbos and general support parts) Toyota WOULD HAVE done something, particularly if the '87-'88 ones were doing so by 1990, while they were still building them new. The Supra was their flagship sports car after all, and at the time, they were still serious about it.
Is the JZ block tougher? Probably. Is it tough enough to survive 20 years of minimal maintenance? I wouldn't bet on it.
Another MkIII;1931110 said:
A million times this.
Also, fel-pro set for the 7M is repackaged shit and a massive rip off. If you're not going OEM on gaskets, get a cheap one because it's the same damn thing (same shit paper EGR cooler gasket when the OEM one is a metallic gasket, same shit throttlebody gasket with the tiny hole for the opening, same shit exhaust manifold gasket that blows out easily and leaks).
Another MkIII;1931110 said:
But for me to fix up any car at this point I would need a loan. I mean I could save up the money but that would take forever, and I want a project car while I am going to automotive school. I mean yes the Supra is more expensive than a little Honda Civic, but I didn't want something everyone else has.
Honda civics are very simple engines, and very reliable. Thats why everyone has one. Don't get me wrong there are also a lot of supras, but I'm willing to bet less then half are on the road. If your not familiar with the surpra, don't have cash to burn, and need a reliable car STAY AWAY FROM A SUPRA. Cut your loses sell the supra for what you can get, and buy a civic cash. Later when you are financially stable, pick up another supra.
I suppose if financial hardship is worth having something not everyone else does (keep in mind it will still be a crappy 25 year old Toyota) then go for it, but you are in for a surprise. Is this your first project car? Keep in mind that any amount of money that you can even imagine that you will need to spend is not going to be half of what you will actually end up needing. Be smart and don't get yourself stuck in the same thing so many others do which is dig yourself into something you cant afford. Honestly man it is not worth it, I would never take a loan out to work on my car/buy parts for my car, it will be a big mistake in the long run if you do.jcarlson73;1931127 said:
S.A. supra;1930952 said:
Over 700 hp on my lowest setting and runs like a champ the past 4 years. Maybe it's time to get a different machinist/assembler. I've messed with these for 14 years.
They can be reliable. Many people boost the crap out of them with 120,000 plus miles and expect them to be like new. lol
IJ.;1931128 said:
And this ^ LOL
x3 been there, done that. I don't have much money as it is to work on my car, but I'm not taking any shortcuts, not borrowing, and I'm taking it one step at a time.IJ.;1931128 said:
if there's anything these cars are good at, it's incurring unexpected expenses; that and getting you to spend much more than you would want to
upgradedsupra;1931147 said:
my friend boosted his w/ 220+k miles and expected it to blow. w/ a gt40-88 @ ~700bhp, it sure did
(VPC)
upgradedsupra;1931147 said:Over 700 hp on my lowest setting and runs like a champ the past 4 years. Maybe it's time to get a different machinist/assembler. I've messed with these for 14 years.
They can be reliable. Many people boost the crap out of them with 120,000 plus miles and expect them to be like new. lol
And this ^ LOL
If You have to say "THEY CAN BE RELIABLE" then their not!
How much do you have in your engine? If someone has to throw money at a engine to make "RELIABLE" then it's not.
I actually blew a head gasket on one of my cars, and all I had was 3 inch exhaust, hard pipes, and apexi intake. The other two I picked up with bhgs, one was from a old man, the other was from a college kid that already had two head gaskets done.
I had mk3 Supra as a daily drive in 1996-1999 and never had any issues. Reason for 95% of 7M-GTE failures sits between the drivers seat and steering wheel. Just my opinion.
Now building one mk3 again and not expecting to have any issues when it's done. Done a full rebuild to engine (stock internals) all new bearings and some small mods. Engine electricals are my biggest concern. Going to check the harnes and all connectors as well all sensors. If something is broken new part goes in. Like others have told remember that it's an old car. Treat it like it's old if not rebuilding it.
Now building one mk3 again and not expecting to have any issues when it's done. Done a full rebuild to engine (stock internals) all new bearings and some small mods. Engine electricals are my biggest concern. Going to check the harnes and all connectors as well all sensors. If something is broken new part goes in. Like others have told remember that it's an old car. Treat it like it's old if not rebuilding it.
I find it funny that all of the crap being put on MK3s are from people who bought them 18yrs after the car was launched and expected it run like new. Almost of the people complaining couldn't afford to fork over the coin to buy one of these brand new. When I hear original owners like SupraCentral and jetjock give their ownership experience I think there's something to note. They all knew about the HG issue by the late 90's everyone knew the fix. I still have Reg Riemers write up on the fix and study of the factory head bolts. Yet all the complaining from people in the masses started when THEY bought the car post 2001. You don't see any members who came from the old sogi and sonic message board bitching. I guess doing it right the first time is the solution.
JDMMA70;1931180 said:
Indeed. It must be remembered this wasn't a Corolla of the period. It was Toyota's flagship, the most expensive car they made sporting the very latest technology. The company's pinnacle at the time. Those of us who paid $26,000 (which was a crapload of money in 1987) for one rightly expected a high quality vehicle designed and built by a company famous for its attention to detail even back then. That said if the OP is willing to borrow money for the car or worse, wants to wrench on them for a living, he has much bigger problems to worry about...