xe rod caps.

[*Dave*]

iv been told that when using ARP rod bolts i need to countersink the bolt holes in the caps.

iv started to do this but changed my mind about doing it, sounds silly but im am only runnin standard power for now.

i have pics below of what i have done so far and would like to know if the cap is usable as it is ??

sorry about the pic quality.. s**t phone !

http://i272.photobucket.com/albums/jj183/davenova/cap2.jpg

http://i272.photobucket.com/albums/jj183/davenova/cap1.jpg

[_JH_]

Sorry, but that cap is no use any more.

You need to get the caps machined to suit the ARP bolts, preferably by an engineer who has done it before.

Incorrect fitting is far worse than using standard bolts.

[*Dave*]

cant they be used as a replacement bolt.?

otherwise iv wasted my money.
seen other people use them without and mods.

[_JH_]

Have you got the bolts there?

[Adam]

Cant see much in the pic, but that cap looks f**ked to me.
When they say countersink, they mean just the centre edge of the hole, not the entire surface where the bolt head sits.

[white2lSR]

The countersinking of the cap is done as the ARP bolts take the stress in different areas as apposed to standard bolts which iirc take the stress at the head.(causing them to let go)

An engineering shop or similar will probably only charge £10-£20 to do the work.

[white2lSR]

Here is a dodgy drawing of a cap. The cross section shows how the top part of the bolt hole is of a larger diameter as aposed the tha standard which is the same diameter through the cap.

http://i141.photobucket.com/albums/r57/rubberrambo/Rod-caps.jpg

[Adam]

Pic of countersinking, courtest of trackdaynovas build thread.
See how just the inner edge is countersunk
http://i136.photobucket.com/albums/q161/neocapture/nc0577.jpg

[white2lSR]

Pic of countersinking, courtest of trackdaynovas build thread.
See how just the inner edge is countersunk
http://i136.photobucket.com/albums/q161/neocapture/nc0577.jpg

God dam you adam, i spent ages on that piece of are and you pull that out the bag :cry:

[Adam]

Never mind eh :p lol

[Dar]

ARP rod bolts have a slight shoulder to them where the bolt head meets the shaft. If you don't countersink them then they won't sit flat. It's only a very small countersink as seen in the photo.

[*Dave*]

ARP rod bolts have a slight shoulder to them where the bolt head meets the shaft. If you don't countersink them then they won't sit flat. It's only a very small countersink as seen in the photo.

mine are completely flat like standard bolts, i cant see on my bolts why i have to counter sink them.

and surely it would say on the ARP packet, or in the instructions about counter sinking,like it says about different torque settings.

[_JH_]

maybe they do a standard replacement bolt [with perhaps a higher-grade steel?] as well as the uprated item. I've only ever seen the chamfered ones

Either way that cap is :gay:

[*Dave*]

well gettin another cap soon + rod, then just using them as standard replacement.

[*Dave*]

are rods different weights?

as iv got another road and cap but were the weights of the rods changed through out the years the xe was made?

just thinkin of the engine balancing

[Dinoman]

The countersinking of the cap is done as the ARP bolts take the stress in different areas as apposed to standard bolts which iirc take the stress at the head.(causing them to let go)

An engineering shop or similar will probably only charge £10-£20 to do the work.

Hi the reason for countersinking is so the ARP bolts will sit flat on the rod cap as if you know anything about stress it is always concentrated in sharp corners, so if you look under the head of the ARP bolt you will see the corner where it sits on the rod cap is radioused to reduce the stress on the bolt head as this is the highest stress area in the bolt, so I always either get ARP countersunk washers that way you do not have to counter sink your rods, I hope that helps, Regards DM

[mayhem]

the arp 'problem'

http://i15.tinypic.com/2mmhll3.jpg
(dutch writing is just saying what dar said)

[mayhem]

btw, why not using the arp bolts? if youre going for more power in the future?