To rebuild or not.

[Zrain25]

My 7mgte has 140,000 no knocks runs great. I'm going to doing the 550 and Lexus mod. I'm putting in a either a full mhg or a comitec or what ever its called with arp bolts. I'm gunna get the head done when I do it. Should I just rebuild the head and put the mhg with the arps or do a full rebuild. I and not planing on doing anything further then the 550 injectors and maybe a 57 trim.

Car will only get 3,000 miles a year. It's my toy.

Thanks guys

 

[7M4EVR]

Depends on whether u want to rebuild the bottom end now when u have the top half already off or in 5000 miles down the road when u don't.

 

[Another MkIII]

First of all, if you're referring to stuff as "whatever its called", you should probably go do some more research. Second, if you are going to do a MHG, you need to machine the block and head. This means you will have the engine fully disassembled. A new set of bearings and forged pistons are cheap insurance, IMO.
-AM3

 

[Zrain25]

I know what it is I don't know how to spell it. It's a metal head gasket. I did plenty of research. I'm not going over 400 hp so I don't need forged pistons. I' know they are stronger and safer. I'm gunna to a compression test on the cylinders to see what they read.

The comitec head gasket has like a rubber type layer over the metal to make it seal to surfaces that arnt perfectly milled.

That is y I want to use it with arp studs or bolts. The engine runs fine I could just put the 550s and afm and run it but I don't want to blow the head gasket. The overheat the engine and have the head and block warped.

 

[Backlash2032]

Well.. seeing as you have to deck the block for a cometic to seal properly, you may as well just do a full rebuild...

 

[Zrain25]

Ok thank u

 

[Zrain25]

How much is it usually to get the head and block decked. And put some bearings and maybe some new ring. I was thinking like 1500 to get the everything done including the mhg

 

[satx88supra]

Sounds like you've made your choice not to rebuild. As others have said....it's great insurance. I know its your toy but its a double edge sword when modding a 7M and not doing what is needed to support the mod. If its your toy the 550/lex mod will lead you to a path to add other mids to properly control the new air/fuel ratio....not to mention you thinking of going 57trim later. All sounds like a duture rebuild when it blows. So again your choice now or later....seems as if you've chosen later on the rebuild.

 

[Backlash2032]

How much is it usually to get the head and block decked. And put some bearings and maybe some new ring. I was thinking like 1500 to get the everything done including the mhg

I did a full rebuild on a GTE+swap from GE with R154 for a grand. But I got a deal on a parts car...

 

[Zrain25]

I'm just wondering what the machine shops charge to to deck the head. Do a valve job put new bearings and rings in. All stock spec no boring over.

1,000 is not bad

 

[BoostMonger]

Depends on whether u want to rebuild the bottom end now when u have the top half already off or in 5000 miles down the road when u don't.

^^ this

youll tighten up the top end and get mad blow by as a reward.

 

[Backlash2032]

Chances are you'll go over 1000. I got lucky. Also didn't get a valve job, and assembled the engine myself.

Sent from my terrible HTC Rezound using Tapatalk. Don't buy HTC...

 

[Zrain25]

Yes I'm going to putting the engine together myself also. Should I get a valve job. Or just let them machine the head and clean it.

Also when you say over a thousand do mean just machine work or including the hg and studs

 

[Zrain25]

Found this on Craigslist I was gunna offer him 600 even though 800 is a good price

What do u guys think

http://providence.craigslist.org/pts/3409563650.html

 

[Dan_Gyoba]

First off, look at what it takes to do a proper MHG.

The block is already completely torn down, as it needs to be decked. The head also needs to be completely torn down as it needs to be surfaced as well.

The difference is basically if you hone the cylinders and replace the rings and bearings. I don't think that honing the cylinders will cost much. I suppose that checking wrist pins is a bit more work, but the cost of the rings and bearings isn't much in the grand scheme of things. Polishing the crank should be done anyway since it's out.

Just do it, and know for certain what you've got.

 

[supraguy@aol]

Anyway, to actually answer your question, yes, i think $1500 would be enough.
Here's my guestimate, assuming you do all disassembly/rebuild:
Hone block. 75
Deck block. 100
Polish crank. 75
Check/resize rods 75
Arp head studs. 120
New bearings. 125
Cometic. 175
Rings. 50
Gasket set. 100
Head job. 300

Total. 1145

Id say add 20% to this for slightly higher machine costs, and little supplies(degreaser, lube, oil, tools, etc), And you end up at around 1500. Like others have said, you could do it for less, but i really think that this is
A realistic and decent cost/value without cutting any corners, for the power level you specify.

 

[supraguy@aol]

Ps- that craigslist ad does look like a bargain.

 

[Zrain25]

Thanks a lot supraguy.

 

[Zrain25]

It's definitely getting rebuilt next winter if not sooner once I get the car back from paint

I don't mind taking the engine out and taping the head apart. But tearing into the block and removing pistons. I might just have the shop do that i never went that deep into an engine. I know I could do it if I took my time. But sometimes just the thought of me forgetting something and a rod going through the pan.... Lol

 

[jonahs_supra]

I would suggest spending the extra couple hundred and having the shop assemble the block
They know what they're doing when assembling an engine and know how to check clearances, set ring gap, adjust valve lash, pressure test head...etc
And not to mention a WARRANTY on motor...something you cant do is give yourself a warranty lol

As for me im going with a stock cardboard gasket with arp's until i get my spare motor built.
My head was going to run me $550 for mill, 3 angle exhaust cut, 5 angle intake cut, reshim valves, assemble and pressure test...this was quoted from a race shop
Ended up going with above and major port job