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2.5L Long Rod Stroker F20C build in progress F25C street & track

Old Feb 15, 2020 | 09:48 PM
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Also, fun fact, i measured all 4 pistons and they were identical at the crown and skirt. Super happy about that.
I will possibly be weighing the complete piston and rod assembly tmr vs the oem ap1 setup.
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Old Feb 18, 2020 | 06:17 PM
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For reference. This is stock ap1





On my F24, the setup weighs 1020 grams using a CP piston and inlinepro f24 rod, but thats with a upgraded, thick wall wrist pin
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Old Feb 18, 2020 | 06:44 PM
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Originally Posted by Charper732
For reference. This is stock ap1



On my F24, the setup weighs 1020 grams using a CP piston and inlinepro f24 rod, but thats with a upgraded, thick wall wrist pin
The picture isnt showing up. Whats the rod length on your setup? Did you weight the parts?
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Old Feb 19, 2020 | 04:13 AM
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Dunno, shows up for me. I forgot what the rod stroke length was. It was not ideal though, I remember that. I gave up on trying to make sense of the stroke ratio and piston speed. Everything I've ever researched says the piston speed of this motor is way out of the safe zone, but I have yet to have it explode or show abnormal wear on the skirts. There are others that take the F24 up to a much higher RPM than I do and they are still fine as well. Mine is set at 8400rpm
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Old Feb 20, 2020 | 04:58 PM
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Originally Posted by Charper732
Dunno, shows up for me. I forgot what the rod stroke length was. It was not ideal though, I remember that. I gave up on trying to make sense of the stroke ratio and piston speed. Everything I've ever researched says the piston speed of this motor is way out of the safe zone, but I have yet to have it explode or show abnormal wear on the skirts. There are others that take the F24 up to a much higher RPM than I do and they are still fine as well. Mine is set at 8400rpm
I see it now. But you weighed it with the bearings. I just weighed my stock AP1 internals and cleaned up most of the carbon. weighed in at 1132g. I have not yet bought bearings.
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Old Apr 10, 2020 | 06:38 AM
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Update! The block is at the machine shop to get sleeved. With the situation we have going on, its going to take a little longer than normal. But as long as its done to my standard (near perfect) Im ok with waiting.
The head is finally ported. It will be going to the machine shop today. Things are looking really good. Now I am trying to figure out the route I take for the injector/rail/regulator combo.






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Old Apr 12, 2020 | 05:41 AM
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More progress. I bought a used Berk header that needed to be cleaned and ceramic coated again. The reason for going with the Berk was because it has one of the largest ID piping in comparison to other headers and i really like how the 2 middle runners are one piece. I also got a real good deal on this particular header. Didnt care how it looked and wanted something used since i was going to cut it up anyways. Since im going to be running high compression and "big cubes" I want to minimize back pressure. The header as it was reducing down to 2.25" at the flange, thats fine for a stock F20/22, but in this case, based on my calculations and potential cylinder pressure, I need to scavenge a lot of exhaust quickly, so OTS it would be a borderline choke. So i bought a transition pipe and cut the header back to where it would match the inlet of the transition. I would have like a little more length to the transition but it will do. It came out great, Im going to have the header cleaned and ceramic coated again. I may also wrap it to reduce heat-soak under the hood. Im soooo looking forward to the dyno session!







Last edited by xBoostx; Apr 12, 2020 at 09:09 AM.
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Old May 6, 2020 | 07:10 PM
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So I will be receiving the block from Inline Pro tomorrow. When i was talking to Jon on the phone he asked me if this was a street car. I started laughing and asked why, he said these pistons are very short, and not the norm for a street engine, hes right LOL, we went a little extreme. He took a pic cause he was pretty surprised at the difference, as am I.
On the left is a IP F24 piston, has a nice dome, so im not sure if its NA specific or their standard piston (theres a few things other than dome that affect final compression). The piston on the left is what a standard forged piston looks like, but next to mine it looks big, its not so, mine is just a more compact profile.
On the right is the piston for this F25 build. My goal is max efficiency, minimal weight and drag. As you can see we did quite a nice job. Side note JE they left some unnecessary material in one spot that i wasnt happy about, piston could still have been another 30grams lighter.



Below is the K24 crank I am using. Its from a TSX. I sent it out to have the balance and runout checked, also a light polish and a magnuflux. Everything checked out perfect.
You can also see the crank modified for the S2000 keyway and the back of the crank which was machined flat.




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Old May 8, 2020 | 08:12 PM
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And the block assembly begins! I will be blue printing the block this week and start putting it together. The head is about a week out, so best case scenario 3 weeks from now we fire it up!








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Old May 11, 2020 | 05:38 AM
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So i ended up buying the Skunk2 Ultra race manifold version 2 for the F20/22. Im probably going to test it on my buddies 2.4 before i put it on mine and buy a throttle body and fitting/regulator for the new IM setup. I already have injectors and rails for the OEM intake manifold setup, but if the big manifold makes power on our big displacement engines then I'll keep it of course. I know it works for boost and isnt ideal for a stock compression F engine but we'll see what happens with super high compression and cams.

here is the manifold with rail and id1050x



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