Hey guys, just want to get your opinion on something that happened today. Im gonna find out tomorrow, but the more opinions I get the more I can look for stuff that maybe I didnt think of.

So today I was heading to the shop and I was doing a long hard pull at 17psi in 4th. Right around 5k I felt a little jolt and at the same time I looked in the rear veiw mirror and seen a tiny puff of smoke. I let off the throttle and actually lost power for a few seconds. I regained power and limped it to the shop.

I did a comp test and I had nothing on cyl 1. I know alot of you are thinkn I threw a rod or piston, but I really dont think I did. Besides the car sounding like its missing, it idles fine. Theres no smoke coming out of the ass end, theres no "bad" noises coming from the motor. The oil looks fine aswell as the coolant.

I pulled all of the plugs out to check timing and that was dead on. Also while I was hand turning the motor, I did take notice that I can spin it with no probs what so ever and again no odd noises.

Im thinkn maybe a blown headgasket or something going on with the valves (which were just installed a month ago).

My whole bottom end is forged with 10.5:1. Ive been running 15+psi for over 3 years now. My AFR maps are near perfect, was at about 11.8 at the time of boost. I just put on a ported head with SS valves and Crane springs and retainers. Im using ARP studs with a Mitsu MLS.

Well I dont think I left anything out, lol.

What say you guys

TIA
DJ

man 10.5 with 15 psi, what kind of ignition settings are you running?

-Keith

'92 BMW 325i - 3.91 LSD....Cold air intake....M52 headers.....Track pipe....Remus back....Fan Delete....UUC short throw...M3 Clutch Flywheel & Drive Shaft...Tien Coil overs

I <3 the twisties

Even more important, what are the cam specs? Dynamic compression determines detonation... not static compression. So the 10.5 is only part of the equation.

**************************************
1995 Eclipse GS - bone stock
2000 Camaro SS - heads/cam/bottle

Welp, the results are in...

I melted the #1 piston.

Like I previously said, Ive been running this setup for a long time now with no probs. Cams were stock along with stock ignition.

Anyways, Ive been having an overheating prob for about the last week. Besides a stuck stat, I was still losing coolant somewhere and I think from what the HG looked like, it might have been going into that cylinder.

So if coolant was geting into that cylinder, then the coolant couldve been working like a blowtorch on that piston and overheated it.

Now is the decision if I wanna just hang it up and get rid of the car and finish my S13/RB project or actually spend the time and money and rebuild. Blaaaah, lol

Thanks guys
DJ

So it just needs a 420a dropped in it?

**************************************
1995 Eclipse GS - bone stock
2000 Camaro SS - heads/cam/bottle

Actually I have a block, all I really need to get are pistons and might aswell get new bearings. Im assuming the rod/rods are still good, lol.

Ouch!

I think it sounds like you know what you're doing over there, so I'd suggest rebuilding it. The car looks great in the flat black, so consider dropping CR a bit - say stock-ish - and just enjoy having a relatively easy-to-tune daily driver with big balls and focus your attention on the s13.

Why scrap out when you've got a good thing going, right?

how did 15+ psi + 10.5 CR feel?

-Keith

'92 BMW 325i - 3.91 LSD....Cold air intake....M52 headers.....Track pipe....Remus back....Fan Delete....UUC short throw...M3 Clutch Flywheel & Drive Shaft...Tien Coil overs

I <3 the twisties

that sounds pretty amazing haha, 3rd gear burn out at 50mph is really impressive, i bet even with the 9.6:1 CR at the 15psi you will be making lots a power, even more reliable too, I wonder how much those custom pistons will cost.

-Keith

'92 BMW 325i - 3.91 LSD....Cold air intake....M52 headers.....Track pipe....Remus back....Fan Delete....UUC short throw...M3 Clutch Flywheel & Drive Shaft...Tien Coil overs

I <3 the twisties

Can't wait to see what you plan now to go with DJ, seemed like it was a beast from what you were describing. Sucks about your luck, but now you can change it up a bit if you want. Good luck

Mike D
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MAN 10.5 COMPRESSION THATS WHAT I HAVE BEEN RUNNING AND EVERYONE SAYS THATS TO HIGH FOR BOOST I ORIGINALLY HAD HIGH COMPRESSION FOR NITROUS BUT GOT TO EXPENSIVE TO FILL IT TWICE ON SAT NIGHTS. WHAT KINDA SETUPS ARE YOU RUNNING. FUEL AND IGNITION.

Mike D
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Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!

I REALLY DONT HAVE A CHOOSE ABOUT USING ALL CAPS TRUST ME I KNOW WHAT IT STANDS FOR BUT I WORK AT A DEALERSHIP AND IT IS PERMENATLY ON FOR WRITING UP WORK ORDERS......SO PLEASE EXCUSE IT.

I'm at a dealer and I still have a no caps function

Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!

Do you have a SHIFT key? You could try holding that down, and you'll type in lower case letters

DJ420a,

For your piston needs, look up Venolia. I got mine through ERT back in the day, but I'm thinking you might be able to deal direct. Depending on how long they hold onto specs, they should still have the specs on my 10.5:1s. Since they specialize in custom pistons, I highly doubt they would have any problems reducing the dome a bit to drop CR to 10.0:1 or whatever. The metal composition is supposed to be first rate. I've been told their pistons will melt before they will crack.

Expansion is very tolerable too. When I had my bottom end put together, I told them I was going to turbocharge things so they set the rings a bit on the loose side. I *do* get a minimal amount of slap at idle until the engine warms up, but you really don't notice it with the lope of the idle. On a boosted application, I doubt you'd hear much, if any, slapping at all.

Google them and check them out. They're quality.

well the caps lock doesnt work but the shift does...... good job edxmon. so is 10.5-1 to high to run boost i am talk about jus 5 or 6 pounds

yeah i have the whole sbr stage 2 block with stage 2 heads and all the gidgets and gadgets, i mean if you are pushing 17 pounds i should be able to get my 5 or 6 i want

Sorry to hear about your car. I was boosting 15psi with a super 16G and 10.5 compression pistons 2 years ago. I ordered a 8.6:1 block, but howell sent me a 10.5 block. I now have a 8.6:1 compression and i feel a difference. The 10.5 felt very nice and i always wondered why the car felt better back then and when i found out about having 10.5, i realized why it felt fast. I loved the 10.5 much better, but decided to take it safe since i have no ignition mods and i still have a sfmu for fuel system. I now have a SC6169, so i bought the 8.6:1 so i can boost 20psi when i get the portfueler system. Good luck with both projects.

99 RS-T
"New bottom end(8.6:1 w/long rods)"
Turbonetics 60-1/Portfueler/etc!!!!!

Originally posted by DJ420a

Originally posted by freddy_00_69 Sorry to hear about your car. I was boosting 15psi with a super 16G and 10.5 compression pistons 2 years ago. I ordered a 8.6:1 block, but howell sent me a 10.5 block. I now have a 8.6:1 compression and i feel a difference. The 10.5 felt very nice and i always wondered why the car felt better back then and when i found out about having 10.5, i realized why it felt fast. I loved the 10.5 much better, but decided to take it safe since i have no ignition mods and i still have a sfmu for fuel system. I now have a SC6169, so i bought the 8.6:1 so i can boost 20psi when i get the portfueler system. Good luck with both projects.

I have the SC61 on the RB cuz I figure its gonna like the SC61 more than the TO4E, but Im actually thinkn about selling the TO4E and getting another SC61 so I will have 2. You gotta give up for Precision, thats just a badass turbo, lol. Are you actually running your 8.6/SC61 setup now? If so, how much of a diff are you experiencing than when you had the high comp? I figure if I was running 15+ on the 10.5, then with a low comp setup, I might be able to run roughly 10 more.....who knows, lol.

99 RS-T
"New bottom end(8.6:1 w/long rods)"
Turbonetics 60-1/Portfueler/etc!!!!!

i know this is going to sound stupid but how do you switch the com, you guys are talking about 10.5 the the stock com, which is better. it looks like you guys know a lot about your cars and i want to know a lot more too. i think that if i read and ask Q's i will learn a lot more so i can run my 420a to its full. i hope to soon run the hahn t20 turbo.

stock compression is like 9:0.1 or some where in that region not positive so dont qoute me if i am wrong. So to chage compression you must tear in to your motor etc higher pistons,rods,shave the head stuff like that.......anybody else feel free to input

very well put

**************************************
1995 Eclipse GS - bone stock
2000 Camaro SS - heads/cam/bottle

My Blog

How else are you going to increase compression ON A STOCK SHORTBLOCK as I specified?

**************************************
1995 Eclipse GS - bone stock
2000 Camaro SS - heads/cam/bottle

Milling a head down so you can go from 9.6:1 to 9.65:1 compression is pretty worthless. Sorry.

My Blog

Why would you only mill it that little bit? That would be silly.

**************************************
1995 Eclipse GS - bone stock
2000 Camaro SS - heads/cam/bottle

milling the head isnt the best way to raise compression as stated above. Milling the head to raise compression may leave the head useless in the future rebuilded because you can only mill so much off our head before it becomes a paper weight. When you spend 1500 in porting the mill off a significant amount, the next rebuild may require the head be milled to the point that the head integrety is compromised. Now you have 1500 in port work that is great for holding your door open.

If you want to raise compression just do it the right way with a set of pistons. Cheating only costs more money in the future.

DJ, dont hang it up. Rebuild it. Before you know it its only going to be a handful of the experienced 420a'ers left. The Icons of this site are slowly disappearing and we are going back to cold air intakes and nitrous for those who think they have a built car. The true built 2GNT is becomming a thing of the past. Before you know it, its going to be Dino, Thura, myself and a few others. Come on Dj.....stick with us. Lets keep 2gnt free of stupidity.

Thanks for explaining that better than I could. I appreciate it.

My Blog

doing it the right way may look like a lot of money but if you are going certain routes the benefits will be well worth it in the end. jus take the process step by step and remember if you can to find another car to drive around for a while dont rush this.

I can relate and agree with you leaning towards going back to higher compression. I was running JE 10.5's after my 2nd build and it was a major difference from the 8.8's when used with a 20g. On my 3rd build I decided to go with 9.25:1 CP pistons. These were a great happy medium and you may want to look up the standard offerings from them. Although I know mine had to be custom made when I got them through VT Engines, they may have more to offer now.



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Santiago
boosted 420a...(2.2l v8 eater)
02 WRX
95 T/A 383ci
03 Harley XL 92ci w/ NOS