MHG/Resurface/Bottom End Rebuild??

gottadiesel

gottadiesel

Flyin Low
Feb 16, 2009
459
0
0
Vancouver, Washington
I know there is much debate in regards to how much HP can you produce on a OEM HG, so I am going to plan to go to a MHG. I understand the reasons for needed to go to a MHG vs OEM running higher boost values and I understand why both head and block need to be resurfaced to utilize MHG.

My question- is it unwise to re-install all lower end parts (crank, rod and pistons) with no change outs or upgrades (if all meets specs still, unsure of cars history)? My plan is to get in the 400hp range with all the planned upgrades/mods I will be making in the process (in simple terms - exhaust, intercooler, boost cntl, fuel cntl, MAF & Turbo).

Bottom line, is that I would like to upgrade to the MHG without replacing any internal parts, yet while it is apart I will certainly inspect all and replace if needed (so that the whole process is not a waste of time and money)

Any and all advice or thumps on the back of the head :icon_bigg will be appreciated.
 
gaboonviper85

gaboonviper85

Supramania Contributor
Jan 13, 2008
3,236
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Northeast Philly
You can indeed lap a block deck while motor is still in the car and together -head....but you need to inspect the deck for warpage first. If you plan on taking the motor appart then you absolutly have to get new piston rings and hone the cylinders as you can't reuse old rings and when you remove a piston the rings will shift and never seal proper again!

You can reuse hardware, rods, pistons (depending on cylinder damage), etc

but if you take a motor appart then at the minimum you'll need to dress cylinders and new rings without question.

My advice you do some research and figure out a budget as lapping a block while the internals are in it is sketchy at best...I myself am doing this but I'm fully prepared too build a motor on the just incase (I have 3 7mgte's waiting for attention)
 
Failure14

Failure14

Banned
May 29, 2009
276
0
0
Ohio
From what ive seen and hear our bottem end can hold pretty well,
ive seen a few people with stock internals hit mid 500's, but like you said
above you dont know the cars history so therefore you wouldnt know how well
it was maintained...

While your doing the MHG you mise well replace the bearings down there to help
prevent a rod knock.

But i mean if you have the money i say do internals, its definetly worth it and will
keep you a little stress free and your 7m will be more likley reliable, not only that it will
help you get into the 400's and definetly further if you decided 400 isnt enough.
 
gottadiesel

gottadiesel

Flyin Low
Feb 16, 2009
459
0
0
Vancouver, Washington
Thanks guys, my thoughts were leaning that way, so thanks for the confirmation. I am thinking once pulled apart I will just check all tolerances and look for damage. At minimum, will have head and block resurfaced to prep for MHG, clean up cylinder walls for new rings, polish crank, new rod bearings and I am thinking new valves depending on condition... Bottom line, if I am going to invest money, I want a motor that is ready for a long haul... otherwise it is all a waste of time and money...

Thanks
 
gottadiesel

gottadiesel

Flyin Low
Feb 16, 2009
459
0
0
Vancouver, Washington
Yes very true, would not make sense to skip crank support....

Ok thanks for the chime in about valves, I am new to these motors (always been the typical small block GM motors) so I appreciate input as to what typical issues will or will not be found...

In addition, I never did list that it has 124k on odometer, but at the same time as I listed, I have no knowledge of its history before I bought it this last spring...

Currently the motor runs great, no issues, no noise (slight and consistent ticking on top end, but thinking normal - will check clearances though), no smoke, good power... my reasons for going through upgrades right now, is that I have two issues, one being the oil pan leaks a fair bit and the clutch is starting to slip with higher torque lower rpm situations (4th and 5th gear @ 3kRPM if you try to accelerate too fast). So I figure if I gotta pull motor for oil pan (at least easiest way I have heard) and then can replace clutch at the same time, might as well go through the motor, as I would like this to be my daily driver, yet be a little more fun :icon_bigg
 
Failure14

Failure14

Banned
May 29, 2009
276
0
0
Ohio
gottadiesel;1443506 said:
Yes very true, would not make sense to skip crank support....

Ok thanks for the chime in about valves, I am new to these motors (always been the typical small block GM motors) so I appreciate input as to what typical issues will or will not be found...

In addition, I never did list that it has 124k on odometer, but at the same time as I listed, I have no knowledge of its history before I bought it this last spring...

Currently the motor runs great, no issues, no noise (slight and consistent ticking on top end, but thinking normal - will check clearances though), no smoke, good power... my reasons for going through upgrades right now, is that I have two issues, one being the oil pan leaks a fair bit and the clutch is starting to slip with higher torque lower rpm situations (4th and 5th gear @ 3kRPM if you try to accelerate too fast). So I figure if I gotta pull motor for oil pan (at least easiest way I have heard) and then can replace clutch at the same time, might as well go through the motor, as I would like this to be my daily driver, yet be a little more fun :icon_bigg
Click to expand...

It starts ticking on top end?!
Definetly not normal....

No ticking inside your motor is ever normal for that matter lol.
 
gottadiesel

gottadiesel

Flyin Low
Feb 16, 2009
459
0
0
Vancouver, Washington
Thanks for the input... probably hard to say without hearing, ticking to one is knocking to another lol... yea I have had some smaller motors (Kia Sportage) that even after adjusting to proper clearance still have a light ticking sound... that is all this sounds like, very light, but I can hear it... anyway I would obliviously shim as required when re-assembling the head anyway...

OK thanks - the fun begins this weekend when motor comes out :icon_bigg
 
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