supra head gasket questions+ rebuild - Page 8

Bill UK · 04-29-2008, 09:21 PM

Andy, it may be worth contacting this guy, he is in the Traders section on the UK site. SIP Racing (location US) http://www.sipracingmailorder.com/servlet/the-71/Toyota-Supra-7mgte-U-dsh-Cut/Detail

Andy C · 05-02-2008, 02:23 PM

picked the head up today all excited about getting it back,
but i put the head on and started placing in the arp head studs and noticed a few are tight and a couple dont go in as far os the others, i looked down the holes and hovvered out before hand so not sure whats up?

unless some do go in further than others any info grateful on these head studs
cheers.

i see the head studs are longer than the original head bolts? im thinking threads holes might be deeper than others.

Bill UK · 05-02-2008, 06:50 PM

Have you tried screwing in an old head bolt to see if you have the same problem, how much longer are the new studs? I would have thought Toyota would have machined the threads deeper than required in the block to allow for the head and block to be skimmed. Sounds like you may have some rubbish in the threads of the hole. I think I would remove the head and use a long thin round brush to clean out the holes (the type spray shops use to clean out their paint spray guns or you may find them in a gun shop) screw in the new studs to see how far they go, you may need to result to cleaning the threads with a machine tap. You should be able to borrow one from the company that skimmed the head. They come in three types, bottoming, plug and taper, I would recommend you use the taper first as its easer to locate into threads without cross threading and shouldn’t cause any block material to be removed providing the hole is deep enough. As this is the most critical part of the engine I wouldn’t take any chances.

Andy C · 05-02-2008, 07:09 PM

i tried one of the old head bolts and it started to get tiff but met the top of the head these stud are about 3cm longer. im sure theres nothinh in the holes?? also i tried tightening the stud fairly tight heard this was wrong and should only be wound in finger tight??

someone was telling me that i need a special tap tool as the threads on the arp studs could be diffrent from your standard tapping equipment

Bill UK · 05-02-2008, 07:42 PM

Bloody hell! That’s over an inch longer; if it screws in to the same depth or deeper than the old bolts then I would think that’s OK. The strange thing is why have they made them so long, perhaps they are used on other car engines like the Mk IV or Skyline. I can’t image any one needing to fit a 30mm thick head gasket. Providing they go in as deep as the old ones, I can't see a problem, providing they clear the camshaft at the top. Is there any one else on the forum that have used studs that can give some input.

Bill UK · 05-02-2008, 07:51 PM

Just thought of something Andy, how will you tighten the nut up if the stud sticks up by 30mm? a standard socket may not fit over the top unless you try a long reach one.

Bill UK · 05-02-2008, 08:08 PM

Another question Andy; is there enough thread left at the top to tighten down the head, I would think you would need a minimum of ? inch or more to be safe.

Andy C · 05-02-2008, 08:33 PM

none of them go in to far just a couple stick up i tried a 3/8 14mm 12 pt socket and it only fits on about 8 i would say. was thinking of replacing old bolts in replacement to the ones i cant work with (arp)

if i turned the studs upside down that will give me a bit more thread on nut as there longer thred on one side.

cant believe im in a pickle already.

also im a bit worried as i was tightened the head studs quite a bit with a 5m allen key dont think i should of done that though the studs alone cant torque the head. this is just what i heard .

Bill UK · 05-02-2008, 10:17 PM

The hole in the head is only a clearance hole, and should have no effect on compressing the gasket if the stud is over tightened. I think they suggest finger tight to allow for the stud to rotate slightly when tightening up the nut. Otherwise if the stud was screwed in firmly into the block and the stud rotated causing it to tightened up even more, the stud would be difficult to be removed using a small 5mm allen key. Using a mixture of old bolts and new studs doesn’t sound a good idea. Read this http://www.aa1car.com/library/2005/eb70536.htm
I know there's a lot or recommendation to use ARP studs, but there is also a lot of Supras that have had BHG repaired using stock Toyota head bolts.The set of APR studs you have don’t sound if they are for a 7M engine. As I said “this is the most critical part of the engine I wouldn’t take any chances”

supramacist · 05-03-2008, 12:50 AM

A deep well 14mm and you'll be good.

You guys are making some of this more tough than it needs to be.

05-02-2008, 02:23 PM	#72
Andy C 3" Exhaust Join Date: Apr 2008 Location: sudbury suffolk uk Posts: 68	picked the head up today all excited about getting it back, but i put the head on and started placing in the arp head studs and noticed a few are tight and a couple dont go in as far os the others, i looked down the holes and hovvered out before hand so not sure whats up? unless some do go in further than others any info grateful on these head studs cheers. i see the head studs are longer than the original head bolts? im thinking threads holes might be deeper than others. Last edited by Andy C; 05-02-2008 at 04:04 PM.

05-02-2008, 07:09 PM	#74
Andy C 3" Exhaust Join Date: Apr 2008 Location: sudbury suffolk uk Posts: 68	i tried one of the old head bolts and it started to get tiff but met the top of the head these stud are about 3cm longer. im sure theres nothinh in the holes?? also i tried tightening the stud fairly tight heard this was wrong and should only be wound in finger tight?? someone was telling me that i need a special tap tool as the threads on the arp studs could be diffrent from your standard tapping equipment Last edited by Andy C; 05-02-2008 at 07:18 PM.

05-02-2008, 08:33 PM	#78
Andy C 3" Exhaust Join Date: Apr 2008 Location: sudbury suffolk uk Posts: 68	none of them go in to far just a couple stick up i tried a 3/8 14mm 12 pt socket and it only fits on about 8 i would say. was thinking of replacing old bolts in replacement to the ones i cant work with (arp) if i turned the studs upside down that will give me a bit more thread on nut as there longer thred on one side. cant believe im in a pickle already. also im a bit worried as i was tightened the head studs quite a bit with a 5m allen key dont think i should of done that though the studs alone cant torque the head. this is just what i heard . Last edited by Andy C; 05-02-2008 at 08:36 PM.

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04-29-2008, 09:21 PM	#71
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	Andy, it may be worth contacting this guy, he is in the Traders section on the UK site. SIP Racing (location US) http://www.sipracingmailorder.com/servlet/the-71/Toyota-Supra-7mgte-U-dsh-Cut/Detail

05-02-2008, 06:50 PM	#73
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	Have you tried screwing in an old head bolt to see if you have the same problem, how much longer are the new studs? I would have thought Toyota would have machined the threads deeper than required in the block to allow for the head and block to be skimmed. Sounds like you may have some rubbish in the threads of the hole. I think I would remove the head and use a long thin round brush to clean out the holes (the type spray shops use to clean out their paint spray guns or you may find them in a gun shop) screw in the new studs to see how far they go, you may need to result to cleaning the threads with a machine tap. You should be able to borrow one from the company that skimmed the head. They come in three types, bottoming, plug and taper, I would recommend you use the taper first as its easer to locate into threads without cross threading and shouldn’t cause any block material to be removed providing the hole is deep enough. As this is the most critical part of the engine I wouldn’t take any chances.

05-02-2008, 07:42 PM	#75
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	Bloody hell! That’s over an inch longer; if it screws in to the same depth or deeper than the old bolts then I would think that’s OK. The strange thing is why have they made them so long, perhaps they are used on other car engines like the Mk IV or Skyline. I can’t image any one needing to fit a 30mm thick head gasket. Providing they go in as deep as the old ones, I can't see a problem, providing they clear the camshaft at the top. Is there any one else on the forum that have used studs that can give some input.

05-02-2008, 07:51 PM	#76
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	Just thought of something Andy, how will you tighten the nut up if the stud sticks up by 30mm? a standard socket may not fit over the top unless you try a long reach one.

05-02-2008, 08:08 PM	#77
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	Another question Andy; is there enough thread left at the top to tighten down the head, I would think you would need a minimum of ? inch or more to be safe.

05-02-2008, 10:17 PM	#79
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	The hole in the head is only a clearance hole, and should have no effect on compressing the gasket if the stud is over tightened. I think they suggest finger tight to allow for the stud to rotate slightly when tightening up the nut. Otherwise if the stud was screwed in firmly into the block and the stud rotated causing it to tightened up even more, the stud would be difficult to be removed using a small 5mm allen key. Using a mixture of old bolts and new studs doesn’t sound a good idea. Read this http://www.aa1car.com/library/2005/eb70536.htm I know there's a lot or recommendation to use ARP studs, but there is also a lot of Supras that have had BHG repaired using stock Toyota head bolts.The set of APR studs you have don’t sound if they are for a 7M engine. As I said “this is the most critical part of the engine I wouldn’t take any chances”

05-03-2008, 12:50 AM	#80
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	A deep well 14mm and you'll be good. You guys are making some of this more tough than it needs to be.