Blew the motor! Rebuild time.
 

Well, my motor blew today during a little cruise at lunch. My setup is in my sig..... 13 PSI on a SR20DET T25, stock 1.8L motor, megasquirt running a very conservative timming map (avg. of about 3 degrees more than DIY's base).

It blew when i was rolling into the throttle in first, maybe 4 or 5k RPMS, it had a sudden lurch, knock light lit up and stayed lit, I shifted into second and heard the MASSIVE tick.

This afternoon I pulled the valve cover off and everything looks normal, I drained the oil and strained it with a paint filter.... and amazingly it was perfectly clean!!!! So its not bearings. I'm kinda stumped. The motor will be out soon pending the weather holding out. Ill keep this updated.


I am just amazed I blew a motor with a t25 and a decent tune. It had 135k on it and even (but low) compression. It dynoed at 98 rwhp stock so it wasnt the most healthy motor.

Enough ranting, sorry for the horrible grammar.

Damn, that sux...:td:

Do all your pistons still go up and down?

Sorry to hear. Well, another stocker bites the dust, and all the more reason for me to wait.

More reason for me to find a 1.8L and put these M-tuned rods in there. 200cc's is an extra 200cc's

The thing runs, idles, and revs, but it is hurting, lol. It even sorda drives ( i was forced to drive it 1/4 mile back to work so i could get a tow after work) Just for shits I will do a compression test today.

yep, and worth every cent for the rods and pistons.

i want to upgrade to a 1.8 as well, but its more than just the price of the engine.
new manifold, MS, wiring harness.

Manifold, yes. MS and wiring harness, no. Your 1.6 wiring, sensors, and computer will work just fine on the 1.8 engine. Upgrading the MS to an MS2 would be optional if you went with an NB block & head.

hmmm, i didnt know that.
its time for me to start searching....

Well that sucks. I need to get a decent tune into mine so it will last until I get a new one.

then either get a job or start sucking. I'd rather have a built 1.6 than a stock 1.8 though.

Just snatch up a blow bottom 99 motor and go from there. I had a 28k mile motor for mine and I'm happy I opened it up and went with forged guts.

A weak motor is a weak motor. I put a freshened cylinder head on a very tired bottom end for an ITA Miata. That head made the car a full 2 seconds a lap quicker. But I knew that extra (compression) power was only going to stress the bottom end. Sure enough, 3 laps to go in the enduro (our last race of the weekend), while running in second place, the engine spun a bearing. And that was w/o boost.

damn this makes me nervous! Even though my motor has still less than 10k on it (prolly less than 6k). Its still only built to stock specs.

How many boosted miles did you last?

Damn, kind of scares me.

3000 miles.... was gunna change the oil this weekend. Its still raining here, so the motor isnt out yet.

Compression test results (No spark plugs, throttle wide open, cold motor)...

175, 50, 175, 125

Something is up....
It was about 175-180 all around when i installed the turbo.

Definitely going to keep following this thread...Let us know what you find out!

how could you not? Its the most rudimentary basic information for anyone with a 1.6.

What octane gas did you have in there?

sonoco 93 octane

More info later but...

Cyl 3 and 4 (left to right)
Attachment 204959

Everything else looks amazing...

SEE...

Attachment 204960

Dude have you found out what's wrong yet?

I have the uber 1.6 engine. I reved it to 7250rpm multiple times a minute for a couple weeks when it was still my dad's car and it spun a crank bearing. Made a clicking noise but seemed to run normally, granted I was easy on it since I knew something was up. We balanced the rotating assembly along with rebuilding it (rings, gaskets, honing, etc), but then my dad assembled it without tightening one of the rod cap nuts, so it came loose and started smacking the valves. It drove less than a 1/4 mile like this before we tore it apart again and rebuilt it. 30k later I turbo it, run it uber lean for a while before finding out (because of my WB) that my fuel pump is bad and am now running a fairly safe bandaid tune. I have no idea how you people keep blowing engines, they're obviously bullet proof. (knocking on wood).

19lbs of boost (spike), 440cc injectors, on a 16g with a stock 1.6 fuel rail = failure. That's how you do it.

And interesting pics above, any ideas?

Those cyl walls look great O_O. Our integra didn't look that good when I put a new head on it 10k miles ago. The pistons even wiggled back and forth in the cylinders :giggle:

Good luck man. I cannot believe you bent a rod on that kind of power...these rods must suck.

Lol, thats not his setup at all.

T25 ftw!

Yeah, I was quite amazed at the condition of all the bearings and cylinder walls. The entire motor other than the rod (and the WEAKKK piston rings) seems to be in great shape.

I have been having some issues with noise in my CAS signal to megasquirt. It would randomly spike to like 65000 (yes sixty five thousand) RPMS...causing the rev limiter to blip for a millisecond and i would have a lean spike with no spark. I always had this happen on highway cruise but I'm thinking this may have been the one time it happened under boost and it just didn't make the rods too happy.

Either way I am excited to rebuild. The head looks decent and I should get away with new rods, bearings, ring, gaskets and a quick clean and hone. Stock pistons FTL, but I think I would rather have a coolant reroute, dual feed fuel rail, and bigger rad before I go bigger pistons and end up convincing myself to turn up the boost or something.

Sounds like a great plan!

That crosshatch is money, amazing for it to still be in that great of shape.

Measure your stock rings and order a set of matching moly rings from wiseco. Then you will have great rings that can stand a beating.

Im putting the engine back together this weekend, getting it back from the shop 2morro i think.

Here are some pics of random progress:

Attachment 204431

Attachment 204432

Attachment 204433

And i got poking when i shouldnt have...
Attachment 204434

Attachment 204435
Pass side was hacked by me in the past and needs to be done right, drivers side was a supprise. Ill be fixing this soon.

Engine bay looks clean :)

I thought that I was going to join you today. I had it running good at 10 psi. I had it at 11 psi and I heard some knock. This is on a 99 9.5 motor so I would guess that's about the same as 13 on a 9.0. Also a T25.

I need to get it back down to 10 before going into boost again.

its sooooooooooooooooooooo nice to have a forged 8.7 motor with 22-28* advance at 15psi. lol

Wow.. I'm def putting my engine rebuild before a few things now...

Unfortunatly I chose to put a few things before pistons on my list, so my build only includes upgrading the rods and ARP head studs. I want to worry about cooling, wheels, tires, and sways before I bother with pistons. I figure before I reach that point I would need a bigger turbo and clutch anyway.

That conrod doesn't look quite right :D
Kinda shocked you blew a rod at that tune. Something must of been real bad in there to do that.

Found out why I have always had low compression and only dynoed 98 rwhp stock...

My head needed to be done. He did a leak test and found a few of my exhaust valves werent sealing...

Oh you gotta love the machine shop Bill :(

If you are spending all of the money on a rebuild etc, why the hell not throw in a set of forged pistons?

Because I am a BROKE college student.. and i expected to run into some things that would already increase the price of my build..... aka my head needing work.

Plus, Ive thought it through, and I will need to upgrade my clutch LONG before I surpass what the stock pistons can hold... And i need new tires and wheels (runnin 205 crappy bald all seasons)

So i guess the question is:

Why not upgrade the turbo so you can then have to upgrade the clutch so you can then have to upgrade the pistons so you then should upgrade the head, but then you really need a coolant reroute and rad. and oh yeah... TIRES.
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$$$$$$$
Trust me I thought long and hard about where my limited funds should go.

Cool man, as long as you've thought it out.

Personally after spending a shitload of money on the expensive part of the build(the build/machine work part), I would without a doubt be putting in full forged internals.

Your argument is not the same, because you do not have to pull apart the motor in order to install a clutch, coolant reroute, tires, etc.

trust me Im sorda regretting it, but I need to pay rent and insurance... and i just bought a winter beater because I really needed a second mode of transporation. You can always pull apart a clean motor and throw it back together as long as nothing is damaged. If I ever have the money for a turbo, clutch, reroute, and tires....... then I will probably have the money to redo the motor as well.

Just lookin out for you man, didn't realize it was already too late in the build for pistons. Either way, nice build.. will continue keeping an eye on it.

Its not... I would just have to pull the wrist pins back apart. Ill kick myself in the ass later, Oh well.

I appreciate you throwing advice at me tho, thats what makes this forum great.

Our builds are nearly the same for exactly the same reasons =P

Yea ur car and my car are way too similar dude.... kinda scary.

I still can't get over the cross hatch on 135K cylinders.