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Post by Matt on Aug 1, 2005 18:17:39 GMT -5
Well another rally not finished due to mechnical!
after having rebuilt the bottom end of the engine, 10 over bearings... and starting the rally with close to 40lbs of oil pressure... by stage 2 we had a rod knock... and 2.5 km into stage three the rod decided it no longer wanted to be part of the game... and exited itself from the engine at about 6000 rpm... what resulted was a horrific bang, and impressive show of oil smoke as most of the oil dumped onto the exhaust system.
Battered, but not defeated we are planning to rebuild... but I'm really getting tired of this problem! perhaps the plan of a 2.5 L is making more sense!
if anyone has any suggestions (other then not running the engine so hard... it's rally for pete's sake!) please advise
Forever pondering the poor internals of the 1.2 L Matt
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SubieGuy
The guy who put a boxer in a Justy. :)
Posts: 191
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Post by SubieGuy on Aug 2, 2005 14:50:46 GMT -5
Bad luck again? How hard do you rev? I revved mine over 9000 rpm in normally aspirated form, and being a rally amrshall, I often had the chance to be the sweeper in local rallies. That meant 8000+ RPM's for a lot of time. But never had such a rod failure. I only replaced my bearings because I was going to turbo my car, and still did not cause problems. Have you had your crank, pistons and rods balanced? Shot peened? How about torqueing? I'm just trying to brainstorm why it would fail in under a couple of hundred km's...
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Post by Matt on Aug 2, 2005 15:48:56 GMT -5
Rev's rarely excced 6000...
the crank was ground by a local machine shop, that does work for all the local circle track boys, so I would think they had decent stuff, it certainly looked and felt good. I examined the pump, and it seemed not bad, a few "swirl marks" but nothing serious. so I used it as is... when the engine went together, it made 55 pounds at start-up, and warmed up it was making 40-45 this tells me that cold the relief valve was opening, but not once it warmed up right?
I thought about torque on the rod ends... God I hope not, I torqued them to factory spec but didn't use lock tight... If upon tearing it apart I find missing nuts... I'll go balistic, but at least I'll know why it died...
break in on the car went something like this... the afore mentioned pressure, then after a few 100 km's (before rally) we were only making 25-30 lbs idle... 40 though when the revs came up. By race day we were down to 20-25 idle, but still 40 above 3000 RPM
first stage saw little drop at revs, but only 15-20 pounds idle... stage two saw 5-10 pounds idle, and down to 35 lbs at rpm over 3000 Stage three, 2 kms in 0 lbs, 0 oil, car no go forward no more! (actually we still drove it onto the trailer, and into the shop!, but gawd what a racket!)
oh and we were running 20w50 race grade oil after initial break in
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Post by DoItSidewayz on Aug 2, 2005 19:58:05 GMT -5
Matt. rip that thing apart and see what is going on.
Did YOU plastigauge the thing before you put it together??
Get that thing back together, and get out to Galway!!
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Post by Matt on Aug 3, 2005 10:13:37 GMT -5
Ah I'd love to be at Galway, however , my relocation has me on the otherside of the continent right now! And much as I'd like to return for the weekend, between now and then there seems no way to telepathically repalce the notor.... My co-drivers going to start workign on it when he gets a chance...
We're determined to make Pines.. maybe Defi, If Galway was Oct like last year it might have been more likely.
No "I" didn't plastigauge it.. I took for granted that it was milled correct..... are you thinking that maybe things didn match up? I guess perhaps an oversized "oversized" bearing would wear quick? delaminate faster?
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SubieGuy
The guy who put a boxer in a Justy. :)
Posts: 191
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Post by SubieGuy on Aug 4, 2005 5:03:29 GMT -5
Now that I know your oil pressure, my best bet is the oil pump. The swirls you have seen are obviously a failing oil pump. Justy oil pumps are not the strongest out there, and when I replaced mine at 200.000km, I had to replace the oil pump cover, rotor and shaft as well, because thay were all "grinded". Another issue seems to be torqueing and loctite. Better luck next time with the rebuild. Bearings mosly fail due to lack of oil. Even if you had over-oversize ones, you'd feel them right away.
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Post by baron on Aug 4, 2005 7:29:37 GMT -5
call me stupid, but would it be a blocked oil way not allowing any oil to certain areas? have you changed all the pipes?!
i know that if you get new internals they need to be heat hardened straight away in their life in the engine otherwise they will fail rapidly....
what about getting a dry sump? get rid of the standard oil pump altogether and tap in an electric one?
also, another possible stupid question, could it be anything to do with the ignition? like bad timing, detnation etc causing havoc with the forces on the crank? im guessing here if you didnt realise!
ive had oil leak for over a year now, thrashed her many times (same with my old justy) at speeds of over 90mph regularly down the motorways, but i have never experienced any broken internals. maybe im not driving her hard enough?!! (i dont do over 90mph now as i had lots of oil come out the gearbox breather and trail down the road behind me) (oops!!)
try an oil additive like Slick 50. that works a treat in clinging to engine components for lubrication. it works for me anyway
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Post by JD on Aug 8, 2005 8:13:16 GMT -5
Ok First I should Introduce myself, I'm Matts co-driver (yep that waky guy in the picturs waving. I spent yesterday pulling the 1.2 and I have some pictures of the carnage however I don't know how to upload them to the forum. If anyone could help or wants to see them please post a reply and I'll arange it.
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Post by DoItSidewayz on Aug 8, 2005 18:04:24 GMT -5
Jeff...fire them off to me and i can try to get them up here.
thefastone121@hotmail.com
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SubieGuy
The guy who put a boxer in a Justy. :)
Posts: 191
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Post by SubieGuy on Aug 9, 2005 14:17:05 GMT -5
I too would like to see them. I guess sideways will take care of them...
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Post by DoItSidewayz on Aug 10, 2005 14:54:53 GMT -5
here's some pictures of matt's motor. Looks like he did a DAM good job. from looking at these i can't figure out what went wrong. If i was you...just get Jeff to rip that thing outta the car, and take it to whoever rebuilt it for you. he should be able to tell you what went wrong.
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Post by DoItSidewayz on Aug 10, 2005 14:57:02 GMT -5
Now that i think...where did you have the timing set??
too much detonation and pinging will kill the bottom end in a short time frame.
Oh yes...Matt...in your relocation..where have you ended up?? still on the canuck side? or state side? I hear your not far from JVL!
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Post by SUBIEJIM on Aug 10, 2005 17:03:08 GMT -5
Matt, Nice job on the engine!! Gotta love the hole in block, I got one like that in my collection too! (Thanks Sideways for the pics) One thing is for sure...It did not let go due to lack of Oil Pressure (The rods and journals aren't blackened and the bearings show no sign of overheating in the pics) My Guess..Rod bolt failure probably due to age and high RPM. If you reused the old rod bolts in the rebuild they were probably stretched from age and use, when you torqued them to spec on reassembly it exceeded their yield point What sucks is they don't break, just stretch then add in some high RPM/load and BAM-OOO!!!! If they were new rod bolts they may have been tightened past their yield point with the same end result. If you have them..look at the rod bolts, I bet you see some thread stretch on them and no sign of overheating. Just my 2 cents Jim
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Post by Matt on Aug 10, 2005 22:17:16 GMT -5
That's the sorta thing I want to hear Jim... because that almost sound plausible from how things progressed...
Chris, timing was set approx 10 dergrees advance at idle.. where we've run before... however... it did actually retard (opps forgot to tighten bolts) durning the lasst transit before explosine... I stopped before stage 3 and reset. then BLAMO and hey yeah the rod ends don't look worn... more like it blew apart... that could further explain it.. The spun out bearing is what confuses me....
I did the rebuild, so no one to blame but me... but we are learning fast with this damn thing so what can I say!
lets see if I can't fit roller bearings into the next lower end, and get oil to the top of the pistons!
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Post by JD on Aug 11, 2005 12:22:45 GMT -5
Howdy again all. Ok the motors out and tore down. Any photo requests. Justy try'n to do my part.... JD (Matts co-driver and newbe engine rebuilder)
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DBA
I'm going to rallye with a Justy
Posts: 121
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Post by DBA on Aug 11, 2005 16:41:18 GMT -5
Well, I'd also vote on bolt failure. But I'd even vote that they weren't tightened at all. They probably were just getting loose and the hits against them in this state were leading to a fatigue failure.
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Post by JD on Aug 15, 2005 8:33:44 GMT -5
New pics of the Block. These may help us figure out what happened, Note that the crank was brocken (pic didn't turn out) at the #1 end. [/img]
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Post by Justyracer on Aug 16, 2005 14:18:54 GMT -5
Woa... thats something ... i hope i wont have any problems whit mine ?
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Post by Matts Co Driver on Oct 25, 2005 9:35:13 GMT -5
Justy too keep eveyone up to speed. The new parts are foinally on there way, many thanks to Bos, Matt and Jamie at chaplins subaru for finding the connecting rod bolts. Wish me luck with the rebuild and hopefully, it will hold together for the last race of the season. JD (Matts C0-Driver soon to be Driver)
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Post by malamute on Oct 25, 2005 15:44:35 GMT -5
Justy too keep eveyone up to speed. The new parts are foinally on there way, many thanks to Bos, Matt and Jamie at chaplins subaru for finding the connecting rod bolts. Wish me luck with the rebuild and hopefully, it will hold together for the last race of the season. JD (Matts C0-Driver soon to be Driver) Could you do us all a favor and measure the the bolt for the following: 1. Overall Length 2. Length of threaded section 3. Diameter of unthreaded section. 4. Bolt head diameter and hex size 5. Thread outer diameter and thread pitch I know I am in the States, but please make all measurements in millimeters. This way we can have new bolts made up from somebody like ARP. That way they will also be stronger than stock. ;D Matthew Bos
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