Milling some rods so they fit STI pistons.
03-13-2007, 11:20 PM
#1
1.0 BAR
Thread Starter
Join Date: Dec 2005
Posts: 397
Milling some rods so they fit STI pistons.
Stock Subaru STI pistons are the ONLY Subaru piston that needs this modification to the end of the rod. Stock STI rods come with the mod already done. Since I am using longer rods (about 1.5 mm), I needed to do it myself.
And the results... About 1.92 mm short of the deck. This is using a 2.2 phase 1 crank in a 2.5 phase 1 block with phase 2 2.5 rods with STI pistons. The stock STI rods had the pistons REALLY below the deck. I will probably be milling down the block about .75 mm.
And the results... About 1.92 mm short of the deck. This is using a 2.2 phase 1 crank in a 2.5 phase 1 block with phase 2 2.5 rods with STI pistons. The stock STI rods had the pistons REALLY below the deck. I will probably be milling down the block about .75 mm.
03-13-2007, 11:45 PM
#3
0.0 BAR
Join Date: Feb 2003
Posts: 0
Re: Milling some rods so they fit STI pistons.
.75 mm, huh? You must be some sort of rich man that you can afford fancy cam gears to dial in your mechanical timing. You SURE you logged onto the right forum?? :P
BTW, last time I had to do that to a set of rods I just dressed them with an angle grinder. Takes about one tenth the time, works great too.
BTW, last time I had to do that to a set of rods I just dressed them with an angle grinder. Takes about one tenth the time, works great too.
03-13-2007, 11:50 PM
#4
1.0 BAR
Thread Starter
Join Date: Dec 2005
Posts: 397
Re: Milling some rods so they fit STI pistons.
Originally Posted by Joseph Davis
.75 mm, huh? You must be some sort of rich man that you can afford fancy cam gears to dial in your mechanical timing.
03-13-2007, 11:54 PM
#5
0.0 BAR
Join Date: Feb 2003
Posts: 0
Re: Milling some rods so they fit STI pistons.
That's an OHC engine. If you molest head/deck height by machining then the mechanical timing is thrown off. A couple thousandths, who cares? Three quarters of a freaking millimeter aka approx 0.030" and you are several degrees out of alignment.
03-14-2007, 12:00 AM
#6
1.0 BAR
Thread Starter
Join Date: Dec 2005
Posts: 397
Re: Milling some rods so they fit STI pistons.
I will research this.
Each tooth on the cam gear is worth 7.5 degrees, so when setting up the timing belt, that is one option.
The other option, is of course to run LOW compression, about 7.3-1 and NO decent quench.
Each tooth on the cam gear is worth 7.5 degrees, so when setting up the timing belt, that is one option.
The other option, is of course to run LOW compression, about 7.3-1 and NO decent quench.
