High Strength Head Studs from MAPerformance
High Strength Head Studs from MAPerformance
For quite a while there were only two choices in the ultra high strength head studs for Evos. There were the ARP L19s, and the Cosworths.
The ARP L19 head studs sell for $225-$299, depending on where you buy them and whether you get on a sale, like at Thanksgiving. They are stronger material, with no special "features" in their design. The first picture below is the ARP stud set, showing the parts you get, and the design of the top and bottom of the stud.
The ARP L19 head studs sell for $225-$299, depending on where you buy them and whether you get on a sale, like at Thanksgiving. They are stronger material, with no special "features" in their design. The first picture below is the ARP stud set, showing the parts you get, and the design of the top and bottom of the stud.
The Cosworth ultra high strength head stud kit is made of the same high strength steel, but has a feature on the bottom of the stud which makes it different -- it is described in the Cosworth USA page here:
http://www.cosworthusa.com/store/pc/...&idproduct=395
Very nice parts -- but $440 a set!
http://www.cosworthusa.com/store/pc/...&idproduct=395
Very nice parts -- but $440 a set!
Last edited by CO_VR4; Dec 18, 2009 at 10:04 PM.
MAPerformance now has sourced and is selling an ultra high strength head stud set, manufactured by A1, who is one of the best known manufacturers of these ultra high strength head studs.
The MAPerformance head studs have the same stud bottom end feature as the Cosworths, but cost $250 shipped instead of $440 plus shipping.
The dogpoint bottom end moves the threads away from the very bottom of the stud. Look at the ARP photo above for comparison. This relieves stress from the block and the stud during clamping -- used in many high end designs for motorsports racing applications...
Here are some pics of the feature and the MAPerformance A1 stud set. They are also broached on the upper end, just like the ARPs and the Cosworths -- I just didn't take a picture of that end of the stud.
More information is available here: http://www.maperformance.com/map-ult...11mmhdstd.html
These studs are very competitive in price with the ARPs, which do not have the lower end feature, and nearly $200 less than the Cosworths, which are directly comparable.
The MAPerformance head studs have the same stud bottom end feature as the Cosworths, but cost $250 shipped instead of $440 plus shipping.
The dogpoint bottom end moves the threads away from the very bottom of the stud. Look at the ARP photo above for comparison. This relieves stress from the block and the stud during clamping -- used in many high end designs for motorsports racing applications...
Here are some pics of the feature and the MAPerformance A1 stud set. They are also broached on the upper end, just like the ARPs and the Cosworths -- I just didn't take a picture of that end of the stud.
More information is available here: http://www.maperformance.com/map-ult...11mmhdstd.html
These studs are very competitive in price with the ARPs, which do not have the lower end feature, and nearly $200 less than the Cosworths, which are directly comparable.
Last edited by CO_VR4; Dec 19, 2009 at 08:52 AM.
The MAP A1s have as good or better tool steel / strength than the ARPs and the Cosworths, but have the better feature on the bottom than the L19s do. Look at the pics of the two bottoms -- the flat bottom ARPs are much cheaper to manufacture, and don't give the advantage that the A1s and Cosworths do...
Some other places may have A1s, but WITHOUT the bottom dogpoint -- SO, be aware that not all A1 studs are equal. Non dog point A1s are similar in quality and cost to the ARP L19s. The MAPerformance A1 studs are comparable to the Cosworths...
The MAPerformance A1 studs were custom ordered, and I am not aware of any other vendor where you can get them, so thanks to MAPerformance for going the extra mile to source and supply something new and improved to the EvoM community.
BTW, I have no relationship with MAPerformance, except as a paying customer.
Some other places may have A1s, but WITHOUT the bottom dogpoint -- SO, be aware that not all A1 studs are equal. Non dog point A1s are similar in quality and cost to the ARP L19s. The MAPerformance A1 studs are comparable to the Cosworths...
The MAPerformance A1 studs were custom ordered, and I am not aware of any other vendor where you can get them, so thanks to MAPerformance for going the extra mile to source and supply something new and improved to the EvoM community.
BTW, I have no relationship with MAPerformance, except as a paying customer.
Last edited by CO_VR4; Dec 18, 2009 at 09:17 PM.
L19 is a term used by ARP for H11 tool steel which is what we used in our studs as well. In all honesty the only difference between our studs and the ARP or A1 variations available from several other vendors is the dog point feature mentioned above. However, when it comes down to achieving an accurate torque spec on a crucial component like a head stud this one feature can help prevent several headaches down the line, head gasket swap anyone? ;-)
