Thanks!

 

Sorry, I was AWOL!

 

It's ok. I should've sent you a pm. I love dealing with you!

 

In all the years ive been in the miata scene I've never seen a head bolt fail, nor main cap bolt. Just curious why so many choose to upgrade?

 

Insurance? Although there is also the argument that you are better off with weaker head bolts that will break before the rod or piston. I imagine the higher torque value on the mains and resulting higher preload might help a bit with crank flex... probably not something you can verify or measure though.

 

In one word: Ignorance.

 

Bought mine on eBay from Seller: importblowoutsales
Head & Main studs for a total of $204- Shipped ~ good seller... quick shipping!
eBay Motors: ARP HEAD STUD KIT 12PT 1989-2005 MAZDA MIATA # 218-4701 (item 180169985754 end time Mar-08-09 10:24:19 PDT)
eBay Motors: ARP MAIN STUDS MAZADA MIATA 1.6L 1.8L 12PT 218-5401 (item 180131300355 end time Mar-07-09 19:43:23 PST)

Best deal I found on ARP main studs are from Seller: carpartsbme
$75- or best offer. shipping is $10- and only $2- more for shipping on a second set!
eBay Motors: ARP MAIN STUD KIT MAZDA MIATA 1.6 1.8 BP DOHC 218-5401 (item 290280053532 end time Mar-02-09 17:32:17 PST)

 

Head-Stockers tend to stretch out after you have the head off a few times and I am sure you can forsee what that leads to.
Main-worthwhile on high powered cars, not on sub 300 I'd say. Reduces crank flex maybe, but I'm not skimping on bolts when I have 1000's in the block.

 

It seems to me that is the case. In all the engines I build I replace the bolts with new OEM replacements and never seen one fail. Ive seen forged Rods bend and all the head bolts were still intact, so not sure that the ARPs are any safer, or what they will even help prevent! But whatever floats your boat!

 

If the head bolts have been reused a few times it is possible they are stretched. I actually had this problem the last time I put my head on (for like the fourth or fifth time), one of the bolts refused to take the last 10 ft*lbs. However, it could have been the threads in the block stripping. I left it at 10 ft*lbs below the rest and so far, it's fine. I'll know this summer if it was the bolt stretching or the threads stripping.

Still, IMO studs aren't needed. I can go to any junk yard and find 50 sets of BP head bolts that have only been used once. And bolts are free at any junkyard I've ever been to. But I've already got another engine to build that's never been apart, so I'll just use those bolts. Point is though the factory bolts are PLENTY strong for the application. Same goes for main bearing caps. Those bitches ain't going anywhere. Adding studs is a 100% waste IMO. They do about as much as a dual feed fuel rail.

 

I dunno pat i like studs and the Dual feed rail having both myself. It is a cheap and viable upgrade plus all the stuff i read about better clamping and over all eveness of them vs bolts is a win. head studs where 75 bucks when i bought mine from FM

 

wait for it...

 

I got studs to make the engine, well, more studly. 18 of those bastards HAS to be good for the stud factor.

But seriously, its relatively cheap insurance.

 

My take on it is maincap studs MIGHT be worth doing, and head bolts aren't. Seriously, am I going to **** myself if I lose a headgasket? No. A block, MBSP, upgraded oil pump, cariilo H-beams... ok, there's some investment. Don't want to lose that. $100? I dunno. Probably the same as the oil pump, probably don't need it but woudlnt' feel bad.

Don't you need to machine the block to get those in?

 

Wow, well, that link for the studs... The "best offer" instantly accepted 10% lower, so I guess I now own some studs. :-) $77.50 shipped. (plus CA tax).

I guess I should have offered 55 like I wanted.
-Abe.
eBay Motors: ARP MAIN STUD KIT MAZDA MIATA 1.6 1.8 BP DOHC 218-5401 (item 290280053532 end time Apr-01-09 18:32:17 PDT)

 

Its nice to hear that Ive helped in some way.

 

Like a dumb ***, I went and offered 55 just to see if he would accept it and he did. If anyone needs a set, let me know.

 

IMO ARP is ideal stuff. It might not be necessary, but as posted, its good insurance..more for the head/block than the mains though. Even then, I'm sure patsmx5 has it right and that the difference is negligible.

What I think is more important is to not reuse either bolts/studs too many times. ARP strictly doesnt want people to reuse the studs as they are torque to yield.

 

I've reused head bolts without issue. The biggest single waste of money on the car ever was buying new head bolts. :-)

I'll trade you for my 77.50 set. For 55 I wouldn't feel too bad. Damnit!

 

No thanks. I actually didn't read the auction close enough and thought I was buying head studs which would be easy to get rid of at that price.