ARP Head Studs

[petert 586]

After doing a few rebuilds this year, I'm over buying head bolts. Especially when I mix and match XU9J4 heads with XU10J4 blocks. I've seen ARP studs for XU10J4 on a web site, but strangely enough, ARP don't list a part number. I decided to do some research. The Dodge 5.9 kit 247-5403 has the same bolt as an XU10J4. The kit comes with 14 studs & nuts (and some other bolts you don't need). For an XU9J4 head you need a longer bolt over the water pump. For this you need just a single AU6.195-2LB.

 

In the pic are standard XU9DTE and XU10J4 head bolts for comparison.

 

I'm building three engines at the moment, so I bought two Dodge kits and three single long studs. Even buying from a dealer in the US and including shipping, they were far cheaper than local quotes and those advertised on another website.

 

The only caveat, is that you need to turn down the OD of the nuts, so they fit in the head. Otherwise, I'm stoked.

[wicked 103 3 Cars]

1 hour ago, petert said:

 For an XU9J4 head you need a longer bolt over the water pump.

AFAIK the XU9 have M11 diameter whereas the XU10's have M12, so won't fly for XU9. 

I do have a set of XU9 ARP studs and suspect it also to be some VW or Mitsu repacked items, but did not find a confirmed match. They also don't come cheaper as the XU9 ones, so stopped searching... 

 

Good catch on XU10 ones though!

[petert 586]

XU9DTE is diesel, M12x1.5. No, these studs have nothing to do with XU9J4 blocks.

[welshpug 1,657]

cummins 24v mains studs, £340 here

 

why anyone would use them over a £25 set I dont know

[petert 586]

36 minutes ago, welshpug said:

why anyone would use them over a £25 set I dont know

That was indeed the price I use to pay. Now they’re $120 a set. The ARP studs were approx. $270 a set, so you can see doesn’t take very long over here to get your money back.

[B1ack_Mi16 67]

Easy to find the kit on eBay: 247-5403

 

But the single stud seem to be harder.. got a link to a relevant webshop?

[B1ack_Mi16 67]

I bought 2 sets of Payen 110mm bolts today, at 15£ a set + vat (which I pay when they arrive here).

So still quite a few sets of bolts to cover the stud price.

 

Also I just moment tighten the bolts below yield, so they are not a problem to reuse.. but for a high power turbo engine I suppose studs are good.

 

For my NA engine it never seemed to be necessary in the past at least.

[petert 586]

I bought the parts from Titan Motorsports, Florida. The single stud was US$12. Ebay prices seem to be exorbitant compared to what I paid.

[grelley 1]

Hi, I have been looking into ARP studs for the XU9J4 and have found that ARP208-4303 fits the bill. These are Honda V Tec studs. They are M11 x 1.5 with 36 mm long thread, and 7/16 UNF on the top thread, x 25 mm long, overall length is 182 mm, so slightly longer. My engine is a BTCC engine and because of the oversize cam followers for the 15 mm lift cam, I have to be very careful that the head bolt spacers don't foul the cam followers.

[petert 586]

9 hours ago, grelley said:

Hi, I have been looking into ARP studs for the XU9J4 and have found that ARP208-4303 fits the bill. These are Honda V Tec studs. They are M11 x 1.5 with 36 mm long thread, and 7/16 UNF on the top thread, x 25 mm long, overall length is 182 mm, so slightly longer. My engine is a BTCC engine and because of the oversize cam followers for the 15 mm lift cam, I have to be very careful that the head bolt spacers don't foul the cam followers.

Nice research. What diameter buckets does the head have? I've seen them so large at Ø35 that the bridge between them cracks.

[grelley 1]

The inlet buckets are 37 mm and the exhaust are 36 mm, which is a bit unfortunate as they don't line up with any standard size bucket. I was told that the cams in the engine were the last version that they tried, but didn't achieve much in the way of extra performance.  When they have machined out for the inlet buckets, they have broken through into where the head bolts are positioned, and the spacers can foul the buckets if you are not careful.

 

[JeffR 51]

Is this the ex Budge car from Melbourne?

[309SRiguy 15]

JeffR,

You can see some history of the BTCC 406 here:

 

https://www.pressreader.com/australia/new-zealand-classic-car/20190422/281547997282243

 

 

[JeffR 51]

Thanks for that article Bryan.

I remember now that the Budges had the '97 cars which one was sold off to a NZ buyer (I believe the other was purchased by Chris Smerdon).

 

[petert 586]

wow, Ø37. There's no need for them to be that large. I know the cam grinds are also too large for the core diameter. So much so, that the camshaft twists allowing cyl#1 to lag behind the others. The core diameter gradually decreases along the cam.

 

To enjoy the car and maintain its originality, I'd build another head with Ø33mm buckets and slightly smaller cams and put the original head safely away.

Edited February 12, 2021 by petert

[grelley 1]

I have 2 engines, both with the same set up. According to Piper Cams who ground the camshafts, they do require them to be that size, otherwise they will contact the edge of the bucket and destroy the lobes. They run Ti valves with relatively low seat and nose pressure so this takes some load off the cams, also they are billet cams so do have some strength in the core. The phase four cams use buckets 1.0 mm less dia.

[SRDT 175]

For a new head you could try to use this but you also need a new cam profile as they're not flat:

[grelley 1]

Here is a copy of the photo posted by SRDT. I have never seen a set up like this. I wonder what the durability of it is like?