was wondering typical weak spots of a 7mgte engine? before i buy, build, and install the 7mgte in the car, want to pull some good HP numbers. 400+ any help from the 7mgte pwrd people id appreciate the help.
ma615mgte
Head gasket. Replace it with a metal one and some arp bolts/studs and you're good for 400hp. I'd shotpeen and polish the rods too as extra precaution, but stock internals are known to hold that power easily.
Christian
Christian
Stock hg torqued to 75ft-lbs has been proven at 350rwhp. The key is controlling detonation. Above that go MHG with ARP studs or headbolts. Make sure your machine shop machines the head and block to as smooth as possible. Often they will intentionally give the surface a slightly rough texture to help bite into a composite HG. Ask them for as smooth as possible.
The other "weak" spot is the rod bearings. Typically these go bad when people run their 7m low on oil, but the #2 cause of death is when a machine shop doesn't do a good enough job matching the crank size to the bearings. Just check your oil level every time you fill up for gas. Often when a turbo starts to go bad, the oil consumption will skyrocket through the roof but the oil pressure will stay at almost the normal level. People who drive 1-2 quarts low on oil will invariably end up with a rod knock.
Other than that, the engine is stout. Make sure the head is straight -- check for flatness at the valve cover surface because sometimes the head will have been machined once when it was warped. This forces the cams to bend (you'll usually see evidence of this in the cam journals -- some scratches are normal and can be polished though).
If you ultimately plan on 550rwhp or more, you'll want forged pistons. Stock rods are good for 700 or more hp -- just make sure they are thouroughly checked out. Shotpeening is frequently done on higher HP builds. A few guys run forged rods, but at $1000/set most people shy away especially since cars with stock rods seem to hold up fine
The other "weak" spot is the rod bearings. Typically these go bad when people run their 7m low on oil, but the #2 cause of death is when a machine shop doesn't do a good enough job matching the crank size to the bearings. Just check your oil level every time you fill up for gas. Often when a turbo starts to go bad, the oil consumption will skyrocket through the roof but the oil pressure will stay at almost the normal level. People who drive 1-2 quarts low on oil will invariably end up with a rod knock.
Other than that, the engine is stout. Make sure the head is straight -- check for flatness at the valve cover surface because sometimes the head will have been machined once when it was warped. This forces the cams to bend (you'll usually see evidence of this in the cam journals -- some scratches are normal and can be polished though).
If you ultimately plan on 550rwhp or more, you'll want forged pistons. Stock rods are good for 700 or more hp -- just make sure they are thouroughly checked out. Shotpeening is frequently done on higher HP builds. A few guys run forged rods, but at $1000/set most people shy away especially since cars with stock rods seem to hold up fine
that and making sure there is always oil in itma71supraturbo said:
and then there is no weak spots IMO =)
The headgasket just doesnt blow by itself
If your going to rebuild the engine, stock everything is what I am doing
Besides a MHG and ARP hardware
Make sure the MHG is prepped and installed properly
well, the hg is about the only weak spot, the rest is just basic engine prep. i personally will never have a head or block machined at a machine shop. i will lap them myself. that way if there is a slight warp, the head will return flat once its tqed to the block as long as it isnt machined. all you have to do is lap it till the imperfections are gone. you dont have to use reg's lapping tool. a piece of plate glass will work just fine and is perfectly flat.
william
william
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