Congrats Joe! The cars looks every bit as good in person too...

 

So what would be the realistic expectation of cost savings of using HR studs over L19's?

 

I believe the factory headbolts are only $50.

 

machining costs as well, if there is a difference.

 

There are no additional machining costs to use the bolts, however you need to clearance the water passages at the front of the block in order to use the HR head gaskets with the redircted coolant flow. It took me about 1hr to get down in there with the die grinder to lower the dividers on each side by number 1 and 2 cyls.

 

I meant between the L19s and HR studs. do the L19s require machining?

 

Not if you get the factory sized ones.

 

+1,

tom you dont need machining, this is why i am not such a fan of the 1/2" cause this are tricky to machine, and people have yet to break them.


ON the topic. I do think the HR bolts will be a good option for the "stage0" build engines......granted this experiment worst, otherwise i would go with l17s on this "stage0" builds.

 

Do you have any pictures of the area that needs the grinding? How much do you have to lower the dividers.

 

those damm n00bs

 

Until there's more data to substantiate that claim (versus the L19), I don't see how anyone can claim one is better than the other... With that in mind, basing selection off of tensile strength seems reasonable.

I would like to hear what engine builders think about using a similar torquing methodology for ARP bolts (slightly less ft-lbs, followed by a fixed angle). After all, all bolts stretch, just to varying degrees...

 

Lets be very clear here a moderator, is here to moderator if the public has been warned not to take a thread off topic then dont go down that route. Dave nore any mod has to pm someone if their post is deleted. If you don't want it removed stay on topic. So that we are very clear this topic is on jkenefic's motor build NOT RA . So what we are saying as mods is talk about jkenefics car only not RA's motor build strategies. Thank you for reading. Accord to FI conduct rules we will continue banning with out warning for those who violate them. Now back on topic

 

rcdash the HR bolts have a slightly superior yield ratting then DE.. but they're very similar. APR studs are torque to spec and as far as I'm aware the HR bolts has the highest yeild rating making them a bolt of choice?

re-edited - romey you have a PM, just some questions???

 

Klumzyee thanks I saw that before. I didn't realize the grinding was for the block. Next time I have to pay better attention. By the way I was quoting your post and my post was deleted at the same time. Such is life. I had others deleted here as well. Wow that was a quick ban.

 

Daaaammmmnnnnn!!!!!

 

Subscribing........

I hate I didn't meet you at ZdayZ Joe.....hell...we couldn't get Louie to leave.....

I better go get my jihad on......

 

The yield strength of an L19 should be higher, right? The problem with a stronger bolt (to my understanding) is that you have to torque to a higher percentage of a stiffer bolt's yield strength to achieve fatigue resistance. In other words the "sweet spot" for a stiffer bolt is narrower and generally the clamping force required greater to reach that sweet spot, and thus the resultant ill effects on the surfaces being clamped (that were not designed for those clamping forces).

Put another way, a stock head bolt tightened to 80 ft-lbs may clamp just fine, but it is unlikely that a 12 mm head bolt will hold sufficient fatigue resistance at that low torque (it will lose clamping force over time). It needs to be tighter and exert a greater clamping force to hold.

All new stuff to me, but interesting.

 

Very good point. Said another way: If you trq a bolt to 80ft/lbs, and a stud to 80 ft/lbs, the stud will have a significantly higher claiming force in between the mating surfaces. The number to look at, IMHO, is clamping force...not trq on a bolt, or trq on a stud. The question I have, and wish I had the time to research and test, is what is the clamping force in PSI of the HR stud (trqed to yield ), and the L19 stud (trqed to spec). I am willing to bet, that the L19 will show signicantly more clamping force.

 

I'm having a 'few' mods done to my EVO while I'm away on my trip, and the first thing that the big name shops (Full-Race, AMS, Buschur) strongly suggested L19 studs with the stock head gasket... The L19's are so widely used on that platform that they can be purchased for ~$200, still double the price of the standard ARps $100 - but a great value vs having to replace the headgasket down the road...

I'm glad people are testing less expensive alternatives, and more importantly providing details on the exact hardware, but call me conservative, I would still recommend at least L19's for our platform at this point.