Blew my 7M, what should I do?

jake8790

Life's too short for N/A
Dec 18, 2011
395
0
0
Oregon
My 7M had been running great for about 8 months with a new oem headgasket and ARP bolts. I was driving around town and floored it in 2nd and when I let off it was only running on 5 cylinders. I drove it 1/4 mile back home with no unusual noises and good oil pressure. I took off the oil fill cap and it was puffing blowby from one cylinder. The next day I tested the compression and found cylinder 4 had 60 psi, all others had 160. The motor had almost 300K on it. I don't know if I should find a shop to rebuild the engine (don't know who I can trust), buy a brand new 7M shortblock from toyota for $3K, or swap in a JZ. I don't have a lot of cash to throw around but I will stretch the project out to afford what I need to so the car is done right. I want it to be extremely reliable and have about 350rwhp. What should I do? :1zhelp:
 

tyang82

New Member
May 12, 2011
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Milwaukee
for 3k, you can fix it yourself and make that hp you are looking for. total rebuild man, rip the thing apart and slap in some npr pistons from driftmotion if you're on a tight budget, get the head checked to see if its straight and not cracked and so on. decide what type of head gasket to use, if metal then deck the block. good luck
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
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Oregon
So would I have good results if I just dropped the block off at an auto parts store machine shop and had it bored over and decked, then put in new pistons and bearings myself? I will definitely be using a MHG and new ARP studs.
 

tyang82

New Member
May 12, 2011
487
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Milwaukee
its cheaper if you did it yourself, thats if you know what you're looking at but if you can take the motor out then Im pretty sure you can tear it apart. just lable every part that you take off so you remember where they go.
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
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0
Oregon
I'm confident about working on the motor but I've never dealt with changing bearings or sizing pistons before. I'm assuming the machine shop will tell me what sizes to order, then I can bring them the parts so they can machine the block for the correct tolerances?
 

tyang82

New Member
May 12, 2011
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Milwaukee
thats a start. decide on how much you want and need to spend then go on from there. if you're confident then start a rebuild.
someone else will chime in also
 

ATL88Supra

The Asshole
Jun 22, 2007
497
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0
40
Atlanta, Georgia, United States
hello jake, i have built 8 7mgte's and i can tell you the most important part is to get that head and block FLAT then get some arp studs (bolts just don't cut it on this motor) then get a nice MHG and some probe pistons from driftmotion

its VERY important that you take your time with this if you rush it you will fuck up and have to do it all over again
so you need to sit down find a nice machine shop and check it out, for any other questions go here http://www.supramania.com/forums/showthread.php?276-Specific-7mgte-Rebuild-Tips
that link is the bible as far as i am concerned.

Good luck!
 

OfnaRcR4

Shea!
Oct 2, 2006
1,340
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kettering ohio
bioskyline;1824874 said:
well before we go rebuilding the motor, id take the head off and see why comp is low in that cyl.

+1, could just be a valve or something simple! Unless you were already thinking of rebuilding seeing how it had 300k.
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
3,811
1
38
Arizona
www.supramania.com
First you need to figure out what happened. Then, I'd find a good machine shop (one that isn't the "NAPA machine shop") and have them go over the block and heads. a full rebuild on a 7M isn't too expensive. Provided you didn't crack or warp the block you can reuse the one you have.

New bearings, block machined for a HMG, head job, new oil pump, etc..

Good times!
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
0
0
Oregon
Even if it's something simple i'm going to rebuild it because of the mileage and so I can run a MHG. I will be installing ARP head studs and most likely ARP hardware in the bottom end as well. I was planning on using Driftmotion's upgraded oil pump. Any tips for finding a good machine shop? Should I just call and ask if they've done 7M's?
 

tyang82

New Member
May 12, 2011
487
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Milwaukee
look for a machine shop that works on performance motors. not being in oregon idont know whats around there. unless you want to ship your stuff out.
 

kotu100

Active Member
Nov 23, 2006
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Easton, Ma
Look for a built 7M, 80% of the time you'll be able to find a fully built motor for cheaper than it would cost to do it yourself.
 

IBoughtASupra

New Member
Mar 10, 2009
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Queens, NY
83Restomod has a built 7M for sale for super cheap. I have done business with him. He bought a 7M fuel rail from me.

Contact him, he is in NJ so it will need to be shipped to you but that shouldn't be so expensive. When you total it out, it will be cheaper, a lot cheaper, than doing it from scratch.

Shoot him a PM.
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
0
0
Oregon
IBoughtASupra;1824998 said:
83Restomod has a built 7M for sale for super cheap. I have done business with him. He bought a 7M fuel rail from me.

Contact him, he is in NJ so it will need to be shipped to you but that shouldn't be so expensive. When you total it out, it will be cheaper, a lot cheaper, than doing it from scratch.

Shoot him a PM.

Thanks for the find! I'm selling one of my motorcycles to fund the rebuild or swap so hopefully it sells soon!

edit: looks like he sold it.
 

MRSUPRA

New Member
Apr 11, 2005
838
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Maryland
You could pull the motor yourself and then dissassemble it. Then you could take take it to a machine shop and have them rebuild it with most of your stock components. If I remember correctly, it cost me about $1200 for the shop to do all the machine work, balancing and assembly of my 7M, and that included new bearings and all the ARP fasteners. (I supplied the forged rods and pistons).

Edit, then obviously you add the cost of the new headgasket, oil pump, and water pump. About $350. And consider getting your head rebuilt.
 

jake8790

Life's too short for N/A
Dec 18, 2011
395
0
0
Oregon
^ hahahaha. I just pulled the head off the car and it looked perfect. Even my composite headgasket looked brand new. The bore on cylinder 4 is smooth and it looks just like all the rest. Now I'm confused.