GVR-4 1g DSM exhaust manifold studs question

[Elpizer2]

The OEM exhaust manifold studs are M8 for this 1g cylinder head, however I want to know if I can mod it to M10 like the 2g cylinder head.

Does it hurt anything? I think one of the threads is a oil return like to the oil pan, just want to make sure if I can make this mod because M10 studs are better than M8

 

[pauleyman]

The OEM exhaust manifold studs are M8 for this 1g cylinder head, however I want to know if I can mod it to M10 like the 2g cylinder head.

Does it hurt anything? I think one of the threads is a oil return like to the oil pan, just want to make sure if I can make this mod because M10 studs are better than M8

2g isn't all M10. Just the outer corners. 1g7 bolt is also.
The middle bolt on bottom goes to an oil drain. Need to put thread sealant on it.

 

[Elpizer2]

2g isnt all m10. Just the outer corners. 1g7 bolt is also.
The middle bolt on bottom goes to an oil drain. Need to put thread sealant on it.

So you recommend me to leave it M8, my outer corners are M10?

 

[DSMPT]

The OEM exhaust manifold studs are M8 for this 1g cylinder head, however I want to know if I can mod it to M10 like the 2g cylinder head.

Does it hurt anything? I think one of the threads is a oil return like to the oil pan, just want to make sure if I can make this mod because M10 studs are better than M8

Like Paul said that not all the 9 studs are M10. 1G and 2G 7 bolt head have Two M10 at lower corner and rest are M8. It doesn't hurt anything, but just keep in mind that if you would have all stud M10, you may struggle when you remove/install the exhaust manifold due to less gap and you may need to enlarge bolt holes on exhaust manifold in some case. And if you replace only two stud with M10 like 7 bolt, some of exhaust manifold gasket is 6 bolt specific. In this case you would need to enlarge the holes on gasket to fit.

outer corners are M10

Then your cylinder head is 1g 7 bolt, or previously modified.

 

[ist dwa]

I run all 10s, 5/16. Iirc you have to drill the manifold flange holes to accommodate the larger studs.

 

[pauleyman]

so you recommend me to leave it m8, my outers corners are m10

That's up to you. Whenever I have an unknown car I replace all the studs. I typically do not change them to M10 but by all means if you want to it's a redrill and tap sitiation

 

[19Eclipse90]

I run all 10s, 5/16. Iirc you have to drill the manifold flange holes to accommodate the larger studs.

10mm (~.394”) is larger than 3/8” (.375”).

5/16” (.3125”) is pretty close to 8mm (~.315”).

Not saying you don’t run all 10s, just not following the numbers there.

 

[pauleyman]

I just realized I wasn't clear. What I mean is if I have an unknown car I will replace all the studs with new ones of whatever size is in there.

I typically do not make the outers 10mm unless they already are. Only the 1g 7bolt and 2g exhaust manifolds will have 10mm outer stud holes. What car do you have? There was no USDM 93 Galant VR4. Is this a JDM car?

A USDM car should have a 6 bolt motor so some things had to have been changed in this car if its USDM. Either a new head or an entirely new motor. VIN tags on the engine will tell you.

 

[ist dwa]

I was trying to go on memory, this is why I have a spread sheet for this, "3/8 - 24 threaded rod, acorn nuts, flat washers for exhaust manifold studs"

 

[buddahboost]

I ground down the power steering bracket/motor mount bracket. I could of ground the 2G manifold, but I didn't think about it that time.

If you need a stud kit, MAP has a kit on eBay for a good price. They got both 6 and 7 bolt kits.

MAPerformance Exhaust Manifold Stud and Nut Kit for Evo 7 Bolt DSM EVO-MSK | eBay

This affordable kit completely replaces the OEM hardware from the exhaust manifold to the cylinder head.

www.ebay.com

 

[1990TSIAWDTALON]

I went with titanium studs. A bit pricey but STRONG.

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[buddahboost]

My head had the bigger outer studs already. I grinded down the bracket as you can see. 2G exhaust manifold on a 6 bolt head.

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