2G Is this normal in the combustion chamber?

[AWD-Tony]

You’re worried about the green? I’d say deck it and send it. I could be wrong. Curious what others think. Maybe it can be welded if it’s an issue.

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[motomattx]

If these were casting flaws we would see them on brand new heads, and we dont.

 

[AWD-Tony]

If these were casting flaws we would see them on brand new heads, and we dont.

If you buy a new head today, are they from the old cast?

 

[AWD-Tony]

I'd like to see if anyone has a head with those marks on #2 or #3 chambers.

 

[1990TSIAWDTALON]

1g or 2g head or both? I have 1 of each bagged up that I could look at. I am pretty sure they have never been touched in that area, so would be interesting to look for.
Tip on cleaning up the combustion chamber...PUT OLD VALVES IN THAT CHAMBER WHILE WORKING ON IT, it makes it impossible to touch the seats.
And a head can be welded. I have a gouge right between to valves so that might be a area that can't be fixed but the teardrop should be easy if needed.

 

[AWD-Tony]

Lets see both if it's not too much trouble. Thanks Marty!

 

[1990TSIAWDTALON]

I will look for them tonight. Which cylinders, or all? I think I have several 1g heads but just one 2g.

 

[AWD-Tony]

Trying to see if those mark are on #2 or #3 cyclinders and/or if they're just on 1&4. I've seen those marks on two different threads since I noticed them on mine. Mine is 1G 6 bolt and OP's is 2g. So which ever is easiest for you Marty.

 

[Simonsaysr1]

You’re worried about the green? I’d say deck it and send it. I could be wrong. Curious what others think. Maybe it can be welded if it’s an issue.

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Yes the one highlighted in green. Idk if decking it would cut that out . I'm sure it's cheaper to get it repaired then it is to get another head.

 

[AWD-Tony]

No that would be way too much to remove BUT decking it will ensure you have a flat surface.

 

[Simonsaysr1]

No that would be way too much to remove BUT decking it will ensure you have a flat surface.

So do you think that it would be more feasible to recondition this head or scrap it and get another used head

 

[AWD-Tony]

So do you think that it would be more feasible to recondition this head or scrap it and get another used head

This will be a cost based decision for you. Honestly don't think you'll have an issue with this head but we won't know until after it's reinstalled. Worst case for this head will be the cost to deck and clean, so about <$100. If it can't hold, a used head will cost between $200-$400 depending on the condition and another $100 or so to clean and deck again.

Like I said before, if it was mine, deck it, send it and pray to the dsm Gods.

You have head studs? People torque them between 80 to above 100 ftlbs. I'd torque your head to 90 or above.

 

[1990TSIAWDTALON]

Reconditioning after a true welding professional has welded up that spot would be ideal.

 

[AWD-Tony]

I've seen this add for a very long time.

https://cincinnati.craigslist.org/pts/d/tyro-dsm-4g63t/6868234433.html

 

[1990TSIAWDTALON]

WOW, lots of odds and ends that are worth picking up.

 

[Simonsaysr1]

This will be a cost based decision for you. Honestly don't think you'll have an issue with this head but we won't know until after it's reinstalled. Worst case for this head will be the cost to deck and clean, so about <$100. If it can't hold, a used head will cost between $200-$400 depending on the condition and another $100 or so to clean and deck again.

Like I said before, if it was mine, deck it, send it and pray to the dsm Gods.

You have head studs? People torque them between 80 to above 100 ftlbs. I'd torque your head to 90 or above.

Sounds like I'm going to try it out. And yes I do have arp head studs. Hopefully itll seal with no leaks. Worth a shot. If this doesn't work I'll hit up that add

 

[AWD-Tony]

WOW, lots of odds and ends that are worth picking up.

I'm not even exaggerating, this guy has been trying to sell these before I picked up my talon, so over a year and a half. Not to many dsm's by me. Only seen 1 turbo and 1 non turbo 1gs.

 

[AWD-Tony]

Sounds like I'm going to try it out. And yes I do have arp head studs. Hopefully itll seal with no leaks. Worth a shot. If this doesn't work I'll hit up that add

Good luck and keep us posted.

 

[1990TSIAWDTALON]

Here is the head I just put on my 6 bolt. I'll look at my others here in a while...
I didn't touch the combustion chambers b4 install.

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It is the factory head off of my 6 bolt auto car and definitely had detonation problems which is why I rebuilt it.
So never disregard your knock sensor!

 

[AWD-Tony]

Here is the head I just put on my 6 bolt. I'll look at my others here in a while...
I didn't touch the combustion chambers b4 install.

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It is the factory head off of my 6 bolt auto car and definitely had detonation problems which is why I rebuilt it.
So never disregard your knock sensor!

Wow That thing looks brand new like it was manufactured in 1990 fresh off the assembly line.

 

[ThunderChild]

Heres some pics of the head off my 97 Spyder. tore it down today and it is bone stock, 142k on it. Pistons showed ZERO detonation evidence, but the combustion chamber ends on 1 and 4 have the exact same marks and don't resemble detonation in any way that I can tell. May have to zoom, and theres a touch of residue/carbon there, but you can see the marks. They're not present anywhere but the outsides of those two cylinders.

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Here's pics of the other CC sides (car sat for a while before I got it so excuse the dirtyness)

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Still not thinking detonation, but either way, the marks could be polished out. I'm thinking it's certain heads manufactured in a time period or factory that had some strange casting flaws due to aluminum quality or manufacturing process.

 

[AWD-Tony]

Heres some pics of the head off my 97 Spyder. tore it down today and it is bone stock, 142k on it. Pistons showed ZERO detonation evidence, but the combustion chamber ends on 1 and 4 have the exact same marks and don't resemble detonation in any way that I can tell. May have to zoom, and theres a touch of residue/carbon there, but you can see the marks. They're not present anywhere but the outsides of those two cylinders.

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Here's pics of the other CC sides (car sat for a while before I got it so excuse the dirtyness)

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Still not thinking detonation, but either way, the marks could be polished out. I'm thinking it's certain heads manufactured in a time period or factory that had some strange casting flaws due to aluminum quality or manufacturing process.

Yikes. That one is rough. Yup I’m certain they’re casting flaws. Not going to see those in 2 or 3. Thanks Thunderchild

 

[ThunderChild]

Yikes. That one is rough. Yup I’m certain they’re casting flaws. Not going to see those in 2 or 3. Thanks Thunderchild

I've seen worse! The pics definitely brought out the detail, but it'll clean up good. Happy to contribute!