2G Bent Valves. First head rebuild.

[Artago]

So my T-Belt snapped (improper tension) at idle. Bent some valves.

The head was rebuilt with aftermarket parts about 30,000 km go.

I'd like to do my first head rebuild. Just trying to compile a list of things I need to replace and maybe get some advice for a "head virgin".

I obviously need new valves.
What else do I need to replace?
Valve guides?
Do I need to take the head to a shop to regrind the angles on the valves?

Photo album here:

https://plus.google.com/photos/112644794890091871636/albums/6067513295525971777

Updating with new photos regularly

 

[lasthope05]

Everything will be done by the machine shop so dont try to "diy" it. The valves that were bent will need new guides because the stock ones are cast iron and usually crack, new valves(replace bent ones or new set), valve stem seals, valve job, and optional resurface.

Its just up to you to decide if you want a stock rebuild, mild built head or fully built.

 

[Kapok6]

Valves
Guides
Stem Seals
Oil Port Mod
If your going for higher HP and/or aftermarket cams, I would suggest springs.


If you have any intentions of making real power, I would advise doing a full build, and not just a stock rebuild. Chances are your stock springs, if they are original, are no longer at any of the pressures they should be. So if your going to replace springs, get good ones.

 

[Artago]

Sorry, should have mentioned. It's a built head with less than 30,000 km on it. No OEM parts left. I had aftermarket cams. Went back to stock (emissions issues).

So for parts:
Valves
Guides
Stem Seals

Can't reused the Guides or Stem Seals? They are fairly new.

Can I reuse my MLS Head Gasket?

What about valve grinding? How does that work? I assume I NEED to get that done?

I will post pics once I get the valves removed (don't have the spring compression tool yet)

Compiling a photos album here:
https://plus.google.com/photos/112644794890091871636/albums/6067513295525971777

 

[arrowhead]

Dont take any chances, leave it to the pros, valve jobs are not difficult but you do need special tools and equipment.
All seals must be replaced, maybe not all the guides will need to be replaced but this is not a call for the inexperience.

Valves and seats will have to be done, as well as checking spring height, and tension.

 

[lasthope05]

You need new valves and they have to be cut for sure. For the guides, its like I said it all depends on the type of valve guides you currently have. The stock cast iron ones usually crack when you bend a valve and will most likely need to be replaced. Aftermarket magnesium/bronze, while being more resilient usually doesn't have this problem but should also be check anyways.

As for valve stem seals, you dont "have" to replace them if they are newish, however, I always do. I like to think the seals get "seated" to the valve stem as the valve rotates and creates its own clearances and for less then $15 why the hell not?

The head gasket issue. Thats up to you. There is always a chance it will seal and also it chance it wont. I've had both happen to me reusing MLS headgaskets. If you're feeling lucky, go for it. If not felpro composite.

BTW, your pictures dont tell/show us anything.

 

[Artago]

BTW, your pictures dont tell/show us anything.

More pics coming when I get off work...

 

[bryanwheat]

If the guides aren't cracked than you likely won't need to regrind the seat with that low of mileage. The only time the seat will need to be cut is if it is pitted from years of use, damaged from the bent valve, or if a new guide is installed. If the guide doesn't crack than you can usually just lap the new valve in and it will seal. You always want to make sure that the valve stem height is correct after the valve is lapped in.

 

[92AWDHX40]

If your ever unsure have everything checked out, if you do a built one make sure its surfaced and have it inspected before you go any further.

 

[yoder]

yeah i was looking into doing a head build myself but really looking up for the tools u need it would save time and aggravation plus if u do it yourself u might over look an important spec and then you could be back to square 1. cause i need a build done and im taking to a guy around here

 

[Artago]

If not felpro composite.

Is this the right one? http://www.summitracing.com/int/parts/fel-9627pt/applications/make/mitsubishi/year/1995

 

[Dsmkauai]

Yup! But why not go thru a supporting vendor from this site!

 

[bryanwheat]

yeah i was looking into doing a head build myself but really looking up for the tools u need it would save time and aggravation plus if u do it yourself u might over look an important spec and then you could be back to square 1. cause i need a build done and im taking to a guy around here

Make sure you find a machine shop that is experienced with these engines. I have had more bad machine work on these heads than good machine work. One of the biggest issues with machine shops is that they don't have the correct size pilot to fit in the guides that centers the seat cutter, or they don't have the correct cutter or stones to do the job properly.

 

[Artago]

Make sure you find a machine shop that is experienced with these engines. I have had more bad machine work on these heads than good machine work. One of the biggest issues with machine shops is that they don't have the correct size pilot to fit in the guides that centers the seat cutter, or they don't have the correct cutter or stones to do the job properly.

Some of the local DSMers suggested the Lordco Machine Shop here.

https://www.google.ca/maps/place/Lordco Machine Shop/@49.109452,-122.665706,15z/data=!4m2!3m1!1s0x0:0x62a26656e0553700

They're a reputable chain parts store mostly. Still weighing my options...[DOUBLEPOST=1412839895][/DOUBLEPOST]As a back up option I was thinking of just buying a new head. Slightly built, nothing crazy. Looking for suggestions as to who does good "bang for the buck" work.

 

[bmxfelon420]

Also dont forget to relieve the head's oil feed. Here's a great instructional video on it

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[Artago]

Also dont forget to relieve the head's oil feed. Here's a great instructional video on it

Will do! I've compiled a list of all the head videos by Jafromobile.

Here is the link: http://www.youtube.com/playlist?list=PLLajBRQbIvxwAeouZCGXqRcwEyhAts5AL

 

[bmxfelon420]

Will do! I've compiled a list of all the head videos by Jafromobile.

Here is the link: http://www.youtube.com/playlist?list=PLLajBRQbIvxwAeouZCGXqRcwEyhAts5AL

Awesome! He has some great info there. I also ground the rough cast out of my main oil passages on the block when I put it together. My oil flow seems to be great, pressure rises very quickly in time with RPM in my car. I actually may need to go to a slightly thinner oil or port out the OFH some more, i see about [email protected] 2800rpm

Not to hijack your thread, just some things to keep in mind in terms of a build

 

[Artago]

This is what was originally in the engine.

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A few months after I got it it had a problem. The head and block were contaminated with media blasting material.

I claimed it under the warranty and the builder rebuilt the whole thing.

However, it is clear he did not replace the parts with what I originally paid for. As you can see the invoice calls for Mahle pistons and not SuperTech. The valves also appear to have been replaced. With stock ones. They don't even match. Some are different.

 

[bmxfelon420]

That really sucks. I'd think that under the warranty you should get what you had into it. I had a similar issue where my car had an engine with about 1200 miles on it that the stub shaft fell out of the oil pump and ruined the engine. No oil pressure=everything ruined basically. The sad thing was the build was over a year old and under no kind of warranty. The car had basically been built a bit at a time and sat around in a barn.

 

[minimarine09]

I had an 03 evo 8 that skipped 5 teeth on the intake cam, ripped the head off, and No (ZERO) bent valves, I thought I was in the Twilight Zone .

I got a great deal from a very reputable machine shop here in Tampa and they replaced everything except for the valves and cleaned up the head really good. There's nothing like a freshly decked head first thing in the morning... Giggity. And for it not being that expensive, why not change every seal and guide. And in my opinion, absolutely get a new hg . I have seen them re seal but it's not worth the risk in my opinion. Good luck!

 

[Artago]

Valve pics:

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Snapped a few pics dropped the head off at a local machine shop.

I'm going to replace the whole set. I may need new guides as well.

Now my question is what valves to buy. Trying to keep the cost reasonable so I'm looking for 'bang for the buck'

Suggestions?

 

[jimsgsx]

How much does it usually cost to have one rebuilt? Stock rebuild i should say.

 

[Artago]

How much does it usually cost to have one rebuilt? Stock rebuild i should say.

No sure. Will have an estimate by Friday

 

[minimarine09]

I had a local shop quote me about 180, that included re deck, new seals and guides, grinding valve seats, hot tank, vacuum seal testing and assembly.

 

[Artago]

I had a local shop quote me about 180, that included re deck, new seals and guides, grinding valve seats, hot tank, vacuum seal testing and assembly.

I just got quoted $550 for the labor + parts.