Rebuild of 7mgte head

[TomFraser]

I have a BHG... I figure while doing the change I should do some work that I wouldn't otherwise do.

First thing is the head on the engine. It has ticking noises, and i'm sure is in a very poor condition. I would like to have it rebuilt by a machine shop.

Any estimates on what a machine shop would charge to freshen up a 7mgte head? Any machinists near Massachusetts (I'm willing to go far to get a cheaper price or support a member I know will do it right) willing to do the job?

I also am wondering what the best way to check the block's surface for warpage is. It was fixed at the last headgasket change about 10k miles ago, and I'm wondering if it is perfect for a MHG (I assume it is not).

 

[EwGoetsch]

I have a BHG... I figure while doing the change I should do some work that I wouldn't otherwise do.

First thing is the head on the engine. It has ticking noises, and i'm sure is in a very poor condition. I would like to have it rebuilt by a machine shop.

Any estimates on what a machine shop would charge to freshen up a 7mgte head? Any machinists near Massachusetts (I'm willing to go far to get a cheaper price or support a member I know will do it right) willing to do the job?

I also am wondering what the best way to check the block's surface for warpage is. It was fixed at the last headgasket change about 10k miles ago, and I'm wondering if it is perfect for a MHG (I assume it is not).

I paid $370 for my rebuild, valves grinded and pressure tested for leaks, cam inspection, and shims and buckets replaced. Only shitty thing is that it still has a feint knocking sound . Make sure you find a reputable shop, not some machine shop that pays some young kid 9$ an hour to do it, cause im pretty sure that what happened to me.
And typically your block is hard to warp cause its iron, just have it resurfaced if anything. ME on the other hand being a broke college kid i just cleaned her up real good with some wire brushes(make sure to get the kind that doesn't scratch your block, don't know what kind, i used my friends) i rebuilt my whole 7mge for about $500 and that's on a very low budget and it runs great with full power at 186,000 miles, even beat the shit out of the motor driving on a frozen river for 4 hours and she never overheated or leaked anything :biglaugh:

 

[IJ.]

Very first test/check should be for hardness, if it fails that it's junk and spending a single cent on it afterwards is a waste of $

 

[DigityD'87]

You might try either JP Chassiwerks in portsmouth NH or Watt's Performance Racing in Seabrook NH. Haven't Experienced either personally but good friends of mine stand by their work.

 

[TomFraser]

i just cleaned her up real good with some wire brushes

What headgasket did you use?

If the block is not being resurfaced should I use a composite headgasket, or can i rely on the blocks old resurface (10k miles ago) to still be a good surface for a MHG? I think I know the answer :nono:.

How can I measure the block's surface to find out if it is acceptable for a MHG?

IJ: Can I personally test for hardness or is this a machinist's job? After a google search and finding expensive machines to do the job I assume this is something to go to a shop for.

 

[radiod]

Very first test/check should be for hardness, if it fails that it's junk and spending a single cent on it afterwards is a waste of $

^ DO THIS FIRST DO THIS FIRST DO THIS FIRST DO THIS FIRST ^

If it's been overheated there's a good chance the head is done. The alluminum anneals, gets soft enough that it won't hold the pressure, and it will crack around the combustion chamber. I speak from experience, I had 3 visual cracks on cylinder 3 and 4 and a complete engine rebuild was done not even 15,000 miles before that. Machine shop should be able to test it for you.

If it is good, make sure your exhaust studs will hold, take the time to time cert or heli-coil the holes that are soft while it's all apart.

I cleaned up my block that was resurfaced on the last rebuild (15,000 miles of driving) with a gasket scraper and some high grit (500 grit) emery cloth. Double checked with a straight edge (or machinist's edge) and didn't find any unhappy spots, so went with it. I used a cometic MHG, and so far haven't had any issues.

The other thing I did while it was all apart was new valve springs. You can either go Toyota OEMs or what I did was get the 2 boxes of the Comp Cams 975-12. They're a higher seat pressure so it will eliminate any chance of floating the valve train at higher rpms and should drop in without too much of an issue. My machine did do a little machining on the spring seats to make them fit a little better, but it wasn't a big issue.

I paid a bit more for my head to get done, but they disassembled the head (brought it down as a whole) and reassembled on to a new one. It was ~$700 and that included pressure test on the new head, machining for a MHG, valve grind, dissassembly, reassembly, shim adjustments, cleaning upper and lower intake manifold, and cam polish.

 

[Keros]

What kind of hardness test should be done to determine the state of the aluminum head?

 

[IJ.]

You're looking for a sclerometer, Zumtizzle sourced mine for me in the USA it's wasn't overly expensive, PM him he should be able to provide the company details.

It's a simple tester that can be used on car so invaluable for a 7M or 7M equipped car purchase.

 

[EwGoetsch]

What headgasket did you use?

If the block is not being resurfaced should I use a composite headgasket, or can i rely on the blocks old resurface (10k miles ago) to still be a good surface for a MHG? I think I know the answer :nono:.

How can I measure the block's surface to find out if it is acceptable for a MHG?

IJ: Can I personally test for hardness or is this a machinist's job? After a google search and finding expensive machines to do the job I assume this is something to go to a shop for.

went with felpro HG cause i got one for free when i bought a 7mgte from a guy for $100. Bad idea, but i can change a HG on a 7MGE in 4 hours, so if it blows im ready. Go for a Metal head gasket, dont be cheap like me, only reason im cheap is cause im unemployed and in college. I didnt resurface my block or check for hardness, and it runs fine, no leaks. I did buy ARP head bolts tho, they help a shitload let me tell you. So get a copper or metal head gasket, ARP head bolts. buy some brake cleaner(works good to get rid of carbon buildup, and some engine bright(a spray can that has a lube like substance to spray your block so it doesnt rust over when you let it sit for a couple weeks. also helps clean cylinder walls. Depending on how many miles, and how many BHG's ur 7M has suffered in order to tell if your block is okay. OH!!!, and make sure if you have to to get your car on a lift, or jack it up and take off the oil pan and check the pump, when your engine overheats the oil gets thick and burned, and can screw up oil pumps. Good luck!!!!!

 

[TomFraser]

Got all the stupid stuff off the head today, all I have left before pulling valve covers and undoing head bolts is removing the turbo (I HATE removing the oil lines), and timing belt.

would've had the head all set to come off if It weren't for the turbo oil lines



So far the list of things to fix while I'm at this are:

CPS cover
Exhaust Studs
All new hoses (vacuum/cooling)
Calibrate TPS
replace stepper motor
New wires
Clean the SHIT out of each piece of the intake
and I'm sure more as I continue to take things apart

Any other things I should be looking at doing while I have the head off? I never want to have it off again?


Upgrades While I'm at it:
CT26 60-1
550cc injectors
Aeromotive AFPR
Walbro Fuel Pump w/12v mod

Still haven't decided on a headgasket, I would like to do metal, but will not be resurfacing the block so I think this is a bad idea. The block was resurfaced about 10k miles ago, so we'll see what I'm looking at when I have the head off. I had a felpro and it failed, so any recommendations on HGs let me know. I plan on running whatever PSI will get me around 400hp (18ish maybe?). Obviously have the supporting mods which are:

Maft Pro (speed density conversion)
BIC DDP Rerouted
3 Inch Pipes
Apexi N1 Muffler
K&N Intake
Hallman Boost Controller (will be replacing with Electronic)
AEM UEGO wideband
HKS SSQV BOV
Arp Studs
Walbro Fuel Pump *to be installed
Aeromotive AFPR *to be installed
550cc Injectors *to be installed
CT26 60-1 Trim *to be installed
Some type of headgasket (IDEAS?) *to be installed, and never BHGed


All I can think of on top of that would be hard pipes and a bigger intercooler to make the 400hp. I'm also still on the auto tranny, gonna stick with it until it blows, any ideas when it might be blowing? I've seen threads say anywhere from 300-400hp. Any input on any of the above, lots of random info, just trying to put everything i'm thinking down.

 

[EwGoetsch]

I'm pretty sure if your block was resurfaced 10k ago, that it should be fine. my block surface had noticeable digs and scratches all over, and it works fine. But im also not running a turbo. Also how many miles do you have on your block? have you checked your rods/pistons/rings and crank? 18 psi might be a a little much if these aren't looked at and in working condition, id start at atleast 12. And be sure to work your motor in before you even start to boost that turbo, id at least drive it for 5000 miles before you fully go out. dont be like my friend who gets a vtech integra, and puts 22 psi on it and floors it 5 hours after his rebuild and blows his motor. I dont know your mechanic abilities im not tryin to insult im just giving advice , go low on boost and work your way up with a good tune, and your engine will last a long time. Oh, and like i said if your block surface is really smooth still get a metal head gasket. or if you want to run mega boost and plan on for more horespower HKS sells HG's that are like $300 Good luck on the tear apart if you have any more problems ill help ya.

 

[TomFraser]

I'm pretty sure if your block was resurfaced 10k ago, that it should be fine. my block surface had noticeable digs and scratches all over, and it works fine. But im also not running a turbo. Also how many miles do you have on your block? have you checked your rods/pistons/rings and crank? 18 psi might be a a little much if these aren't looked at and in working condition, id start at atleast 12. And be sure to work your motor in before you even start to boost that turbo, id at least drive it for 5000 miles before you fully go out. dont be like my friend who gets a vtech integra, and puts 22 psi on it and floors it 5 hours after his rebuild and blows his motor. I dont know your mechanic abilities im not tryin to insult im just giving advice , go low on boost and work your way up with a good tune, and your engine will last a long time. Oh, and like i said if your block surface is really smooth still get a metal head gasket. or if you want to run mega boost and plan on for more horespower HKS sells HG's that are like $300 Good luck on the tear apart if you have any more problems ill help ya.

My mechanic abilities are none, pretty much everyone here knows more than me. I learn by doing and listening to IJ

Bottom end was rebuilt (with receipts) 10k ago when the block was resurfaced. All stock stuff, but a rebuild nonetheless.

One the head comes off I'll post pictures of what i'm looking at so we can all decided the best path to take.

I plan to take the first 1000 miles VERY easy, then re torque bolts and start driving a little "sportier".

I appreciate all advice you have, and I'm never insulted by someone trying to help, the more input I get the better off I am.

Thanks to all for the replies.

 

[IJ.]

Damn Lad you're DOOMED don't listen to that guy

 

[EwGoetsch]

I was just like you a year ago had no idea what i was doing, then i started taking things apart, learning where they go, how it works, and also a camera helps out a lot to remember where certain bolts go. Supramania was a life saver for me during when i started takin my motor apart, and tons of nice ppl willing to help you out and get you the parts you need very easily.

 

[TomFraser]

Alright everthing removed, head nuts off, but the head won't budge, two people can not pick it up, I belive everything is off, just keep pulling?

 

[TomFraser]

Alright everthing removed, head nuts off, but the head won't budge, two people can not pick it up, I belive everything is off, just keep pulling?

yep... just keep pullin

Had to remove the rearmost 4 studs to get the head off (already had arp hardware)

Cylinder 2 blew, not bad at all, i'll post pictures later.

Block is in good condition, can still see crosshatching in cylinders.

Head is off to machine shop tommorow for hardness testing.
-If it is still good I'll dissasemble it and have it hot tanked, new valves, and the whole bit.

Block's actual gasket surface is in very good condition, I think I'm going to start smoothing it and see what it looks like. If it is perfect MHG, if not then some type of composite.

What type of metal headgasket should I use? (not sizing, but brand). What type of composite should I use if I go that route?

I'm planning on as much as 18-20psi after all my mods are said and done with, so I need to be able to handle that.

 

[IJ.]

Crosshatching doesn't really mean much in a block this hard, they don't wear like most cast iron engines.

 

[TomFraser]

started a build thread... figured i'd post and update about my old head (which is junk) and how i'm prepping the block for a MHG, (don't shoot me)

http://www.supramania.com/forums/sh...(400hp-goal)&p=1519723&viewfull=1#post1519723

 

[suprarich]

Fiqure out what size gasket you need first before you worry about what brand to buy. Some manufacturers are limited in selection.

 

[TomFraser]

Fiqure out what size gasket you need first before you worry about what brand to buy. Some manufacturers are limited in selection.

I plan on cometic because of the RA spec under 50 not 20 and they are great about custom sizing for relativley cheap