|
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.
http://www.vincentfurniture.com/phot...sofstirods.jpg http://www.vincentfurniture.com/phot...ofstirods2.jpg 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. http://www.vincentfurniture.com/phot...phase2rods.jpg |
Re: Milling some rods so they fit STI pistons.
WTF the pistons arnt PINK? ???
|
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. |
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.
|
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.
|
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. |
Re: Milling some rods so they fit STI pistons.
Take the middle layer of the HG out ud probably be in the mid 8's after that
|
Re: Milling some rods so they fit STI pistons.
|
Re: Milling some rods so they fit STI pistons.
Yeah, making the right rod look like the middle rod at the crank end!
|
Re: Milling some rods so they fit STI pistons.
Post pics of your mill. Looks good mang. |
Re: Milling some rods so they fit STI pistons.
Man, that shiny block would look right at home in my subie ;D Not to thread jack, but does anyone know how well the sleeves of a 97 dohc ej25 hold up under boost? Just made me think about it seeing that block pictured with the open deck :-\
|
Re: Milling some rods so they fit STI pistons.
I assume your going for 600+ whp then?
Rode in a 450 whp Sti this week, stock block and tranny. Nothing like dog tracking looking for traction in 3rd gear. |
Re: Milling some rods so they fit STI pistons.
I don't see how a 3000 lb AWD car has traction problems at 450whp. Piss poor alignment? ???
|
Re: Milling some rods so they fit STI pistons.
Originally Posted by Joseph Davis
I don't see how a 3000 lb AWD car has traction problems at 450whp. Piss poor alignment? ???
Quick boost spike to 600ft-lbs. :P |
Re: Milling some rods so they fit STI pistons.
Originally Posted by Joseph Davis
I don't see how a 3000 lb AWD car has traction problems at 450whp. Piss poor alignment? ???
|
Re: Milling some rods so they fit STI pistons.
Correctly aligned but completely bald Azenis, slightly heated which makes a difference on the street although it's a disaster on the track, skip in and out of traction in 2nd on Goforth's 1900lb CRX which has a hell of a lot more power than 3000/450 even at low boost.
Someone somewhere is a stupid little monkey. :3 |
Re: Milling some rods so they fit STI pistons.
Originally Posted by Joseph Davis
Correctly aligned but completely bald Azenis, slightly heated which makes a difference on the street although it's a disaster on the track, skip in and out of traction in 2nd on Goforth's 1900lb CRX which has a hell of a lot more power than 3000/450 even at low boost.
Someone somewhere is a stupid little monkey. :3 |
Re: Milling some rods so they fit STI pistons.
Currently LS 1-4 and FD with GSR 5th. Check your PMs for the current blow-by-blow on the 1/4 mile assault on the 9's taking place right now.
|
Re: Milling some rods so they fit STI pistons.
Originally Posted by slo_crx1
does anyone know how well the sleeves of a 97 dohc ej25 hold up under boost? Just made me think about it seeing that block pictured with the open deck :-\
http://www.vincentfurniture.com/phot...dcylinders.jpg |
Re: Milling some rods so they fit STI pistons.
They used to do that to Honduh blocks ten years ago, I dunno who started it but Benson's made their original name doing that. They used more pins, tho.
Time has proven that we can make 500-650 off of stock sleeves... are you sure Scoobies aren't the same? Most of you guys run small turbos which build up heat in the engine, and then rely on a dummy knock sensor to take care of your ignition while you flog the ---- out of your rides for sustained periods in autocross, roadracing, hillclimb environments. For crying out loud, you ---- multiple pistons and your sleeves are fine even after what has to be a couple seconds of hardcore detonation before the piston comes apart! It really does sound to me like your stock blocks are very strong, just like Honduh stuff. |
Re: Milling some rods so they fit STI pistons.
The larger 2.5 NA blocks (which I am using for this motor) supposedly often suffer cylinder walk. So I took some cheap preventative measures. If it helps, it helps.
"Should" be running by next weekend, if not this weekend, wating on the clutch (should be here Wednsday), and a buddy is reworking the heads.... Whoops, that reminds me, I need to order the Meth kit.... |
Re: Milling some rods so they fit STI pistons.
People claim cylinder heads lifting with D-series that were shifting bores under detonation. D-series heads don't lift.
This is a HUGE apples to asparagus type comparo, I know dick about Scooby, but there's a lot of bad tech passed about on message forums. Even if the 2.5 cylinders do walk... what causes it? Timing for best power when you're taking WOT pulls on the dyno every two minutes might be too advanced when the engine gets heatsoaked because you're flogging on it for a sustained period in the real world... or too retarded from a knock sensor feedback loop. Either will destroy an engine :-\ Anyway, I'm going to STFU now because you did an outstanding job your first time around, and because I know dick about Scooby. Forgive me if I get al blah blah blah, your car makes me all sweaty palmed and happy to look at. |
Re: Milling some rods so they fit STI pistons.
You give "constructive" criticism, so I will listen to you.
Others? I wish I could "mute" certain users. |
Re: Milling some rods so they fit STI pistons.
As a honda and suby owner I have thought exactly the same thing. The way I see it is, honda community has a huge head start (cars from 1988 and up to choose from) and have really taken advantage of what engine management can do. Subaru community on the other hard have just gotten their feet wet and are just recently figuring out how much more capable self engine management can be than off the shelf maps.
Originally Posted by Joseph Davis
They used to do that to Honduh blocks ten years ago, I dunno who started it but Benson's made their original name doing that. They used more pins, tho.
Time has proven that we can make 500-650 off of stock sleeves... are you sure Scoobies aren't the same? Most of you guys run small turbos which build up heat in the engine, and then rely on a dummy knock sensor to take care of your ignition while you flog the ---- out of your rides for sustained periods in autocross, roadracing, hillclimb environments. For crying out loud, you ---- multiple pistons and your sleeves are fine even after what has to be a couple seconds of hardcore detonation before the piston comes apart! It really does sound to me like your stock blocks are very strong, just like Honduh stuff. |
| All times are GMT -5. The time now is 02:01 AM. |
© 2024 MH Sub I, LLC dba Internet Brands