McCoy
11-25-2009, 01:16 PM
So tonight I finally decided to crack the motor open now that I have the 240 running again with the redtop DET.
S13 SR20DE head off.
http://www.prmsg.org/albums/album107/SR20DE_head_off.jpg
#3 cylinder wall, facing towards the exhaust side.
http://www.prmsg.org/albums/album107/SR20DE_head_off_no3_ex_side.jpg
#4 cylinder and piston... looks ohh so familiar.
http://www.prmsg.org/albums/album107/SR20DE_head_off_no4_ex_side.jpg
#4 cylinder head
http://www.prmsg.org/albums/album107/SR20DE_head_off_no4_valves.jpg
A little background. I ran the car last year at a track day with temps in the mid to upper 90's. Boost was set at 12psi and I was running the S14 T28 at the time with a JWT ECU and 91 octane (best we got around here). Just before noon I started to notice a miss under boost, which got worse as I got through the lap. I pulled in and started looking for the boost leak that I thought I had. When I didn't find anything wrong, I decided to pull the plugs and found #2 partially melted and #3 and #4 mostly gone. Wanting to finish my day, I threw in a new set of plugs from napa and ran the rest of the track day at 10psi with no problems.
Spark plugs I pulled...
http://www.sr20forum.com/gallery/data/959/medium/aug_08_track_day_plugs.jpg
Fast forward to this past spring, I finally got around to doing a compression test and found that #2 was down by a good 20psi from #1, and #3 and #4 were down by 40-45psi, dope! I still ran the car another 2 track days this year before getting the redtop freshened up and did the swap over the past 4 months... it could have been faster if I wasn't old and decided to throw the back out.
I need to get the pistons out and clean up the mating surface to see how bad things really are. I'd like to reuse this block/head, but well see once I get it torn down some more.
S13 SR20DE head off.
http://www.prmsg.org/albums/album107/SR20DE_head_off.jpg
#3 cylinder wall, facing towards the exhaust side.
http://www.prmsg.org/albums/album107/SR20DE_head_off_no3_ex_side.jpg
#4 cylinder and piston... looks ohh so familiar.
http://www.prmsg.org/albums/album107/SR20DE_head_off_no4_ex_side.jpg
#4 cylinder head
http://www.prmsg.org/albums/album107/SR20DE_head_off_no4_valves.jpg
A little background. I ran the car last year at a track day with temps in the mid to upper 90's. Boost was set at 12psi and I was running the S14 T28 at the time with a JWT ECU and 91 octane (best we got around here). Just before noon I started to notice a miss under boost, which got worse as I got through the lap. I pulled in and started looking for the boost leak that I thought I had. When I didn't find anything wrong, I decided to pull the plugs and found #2 partially melted and #3 and #4 mostly gone. Wanting to finish my day, I threw in a new set of plugs from napa and ran the rest of the track day at 10psi with no problems.
Spark plugs I pulled...
http://www.sr20forum.com/gallery/data/959/medium/aug_08_track_day_plugs.jpg
Fast forward to this past spring, I finally got around to doing a compression test and found that #2 was down by a good 20psi from #1, and #3 and #4 were down by 40-45psi, dope! I still ran the car another 2 track days this year before getting the redtop freshened up and did the swap over the past 4 months... it could have been faster if I wasn't old and decided to throw the back out.
I need to get the pistons out and clean up the mating surface to see how bad things really are. I'd like to reuse this block/head, but well see once I get it torn down some more.