My 2G cylinder head is at the machine shop and they asked if I wanted to upgrade the head bolt hole washer to either a 1" washer or the ARP insert washers. The purpose is to help keep the head from squishing as you torque the head down. I like that the inserts have a short sleeve that goes down into the head unlike the 1" flat washer. Seems like both options do the same thing just in slightly different ways? You have to pick one can't use both. Anyone got either of these in their head? I went with the 1" washer as they told me it would help evenly distribute out the clamping load on the cylinder head.

More machine work if you do not mind it and the added costs for it.

Nearly went down that route myself but then decided to make hardened washers for the head size which works better and is drop in. Keeps full wall thickness also.

Im running L19's on 100ft lbs torque cut ring gasket.

I run the ARP insert washers, I also posted a video on how to install them yourself if you have a drill press, it's really not overly complicated.

The advantage they have over normal washers is they physically keep the head from crushing in around the stud at higher pressures. I would highly suggest them to anyone looking to run over 30 pounds of boost.

9 T GSX said:

You have to pick one cant use both

Click to expand...

Not the ARP insert washers but I have been running both 1" washers that came with 1/2" L19 studs and TMZ (@twicks69 ) shouldered dowels in my 1g.

I will have the shouldered dowels back in stock in the next couple weeks, all sizes are being machined for restocking.

DSMPT said:

Not the ARP insert washers but I have been running both 1" washers that came with 1/2" L19 studs and TMZ (@twicks69 ) shouldered dowels in my 1g.

TMZ Performance DSM/Evo Shouldered Dowels For Cylinder Head Reinforcement (11mm, 12mm, 1/2″)

www.tmzperformance.com

Click to expand...

Interesting I didnt think you could run both.
Tim checked your site and says 12mm are in stock this true are they being made as well?

All sizes of the dowels are being made currently, ETA is supposed to be 2-3 weeks.