Author Topic: 11mm Head Studs  (Read 4028 times)

July 18, 2010, 06:44:31 pm

8v-of-fury

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11mm Head Studs
« on: July 18, 2010, 06:44:31 pm »
I was thinking, instead of paying the super big price of ARP head studs for an 11mm engine.. what about going with a slightly lesser strength stud.. That would still be gobs and gobs stronger than stock head bolts, and only used on an N/a or mild turbo application? The bolt grade would be 12.9.. which is a fairly strong fastener.

To quote a knowledgeable person;

Quote from: A Smart Guy
The 12.9 is about 20% better than normal 10.9, but still 25% shy of arp and the elongation isn't there either...bad rod bolts, but good for everything else

Also I was thinking while at it, I could get the studs to be a little longer so we can get them deeper in the block to get some more grabbing surface..

These are not specific for automotive use, they just so happen to be the right size.. What would be the perfect dimensions of said bolt?? Length and all that junk.

What do ya think!?

Reply #1July 19, 2010, 09:44:06 am

Rabbit on Roids

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Re: 11mm Head Studs
« Reply #1 on: July 19, 2010, 09:44:06 am »
i like studs.. they dont have any twisting torque on the threads in the block. just straight pull.. you can tighten a stud alot tighter just because the actual stud doesnt have any twist in the thread boss as your tightening it..

for some reason i thought you were talking about 12.9 bolts.., not studs, sorry..
« Last Edit: July 19, 2010, 12:42:55 pm by Rabbit on Roids »

Reply #2July 19, 2010, 12:06:50 pm

rs899

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Re: 11mm Head Studs
« Reply #2 on: July 19, 2010, 12:06:50 pm »
Sounds good to me, but what do I know?  Where can you get such a non-automotive use 10.9 stud, pray tell?
'91 Jetta 1.6 NA, '82 Caddy 1.6NA, '81 Cabriolet,  4 Mercedes OM616/617s , 2 Triumphs and a Citroen DS19 in a pear tree.

Reply #3July 19, 2010, 09:36:51 pm

8v-of-fury

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Re: 11mm Head Studs
« Reply #3 on: July 19, 2010, 09:36:51 pm »
Sounds good to me, but what do I know?  Where can you get such a non-automotive use 10.9 stud, pray tell?

Non-automotive use 12.9 Stud ;)

Reply #4July 19, 2010, 09:58:33 pm

rabbitman

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Re: 11mm Head Studs
« Reply #4 on: July 19, 2010, 09:58:33 pm »
I think it would be fine, as for the depth, I'd want it all the way to the bottom of the hole but not tightened.
'82 Rabbit, I put on a euro vnt-15, 2.25" DP, 2.5" exhaust, the result.....it whistled.

I removed the turbo, made a toilet bowl 2.5" DP, the result....it was deafening. Now it has a homemade muffler up front and a thrush in the rear, the result.....less loud.
Watch: AGENDA, GRINDING AMERICA DOWN

Reply #5July 20, 2010, 06:56:27 am

8v-of-fury

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Re: 11mm Head Studs
« Reply #5 on: July 20, 2010, 06:56:27 am »
all the way to the bottom of the hole but not tightened.

Arr this be what me needs to know. (pirate accent) Stock bolts are like what 98mm? would 105 be too long? How far in to the block do the holes go?

Reply #6July 20, 2010, 08:12:55 am

Rabbit on Roids

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Re: 11mm Head Studs
« Reply #6 on: July 20, 2010, 08:12:55 am »
all the way to the bottom of the hole but not tightened.

Arr this be what me needs to know. (pirate accent) Stock bolts are like what 98mm? would 105 be too long? How far in to the block do the holes go?

i would say they go in the block atleast 30mm

Reply #7July 20, 2010, 11:34:42 am

clarkrep

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Re: 11mm Head Studs
« Reply #7 on: July 20, 2010, 11:34:42 am »
Before you get too involved in the length you need, you might check availability for that thread size.
I measured a factory head bolt and it's M11x1.5 Neither Mcmaster Carr nor MSC have anything in 11mm. You might be able to find them through a specialty faster supplier but I kinda doubt it since the Machinery's Hand doesn't even show it as a thread.
Makes Raceware studs sound better even though they're like $185.00......
'79 Rabbit Diesel L 1.5
'83 Rabbit GTI 1.6TD

Reply #8July 20, 2010, 12:09:55 pm

Rabbit on Roids

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Re: 11mm Head Studs
« Reply #8 on: July 20, 2010, 12:09:55 pm »
arent ARP studs just a bit over 110 bucks thru summit racing?

and ARP studs are supposed to be leaps and bounds better than raceware..

Reply #9July 20, 2010, 12:24:04 pm

clarkrep

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Re: 11mm Head Studs
« Reply #9 on: July 20, 2010, 12:24:04 pm »
I don't know if you can get 11mm ARPs. My 12mm ARPs cost about $130.00 a year or so ago.
'79 Rabbit Diesel L 1.5
'83 Rabbit GTI 1.6TD

Reply #10July 20, 2010, 03:28:24 pm

tSoG-84bit

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Re: 11mm Head Studs
« Reply #10 on: July 20, 2010, 03:28:24 pm »
11mm arps in my 4dr. same as gasser studs. 100-150 bucks. I don't think you'd save any munnies w/ 12.9 studs, since you'll be custom ordering them by the sounds of it. spend the extra, get some peace of mind w/ your order.
84bit 1.6na
Engine died, pulling it apart, putting something new in it's place.

Reply #11July 20, 2010, 06:48:27 pm

8v-of-fury

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Re: 11mm Head Studs
« Reply #11 on: July 20, 2010, 06:48:27 pm »
if i can get the 12.9 studs for $20 shipped I think I'm saving a little bit of coin no?

Plus 12.9 studs are only 25% less then ARP.. and that is still %20 more than normal 10.9. I think for a stock application or even stock boosting levels.. i think it will be perfect