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DavidSweden |
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#1
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Member ![]() ![]() Group: Members Posts: 479 Joined: 8-June 14 From: Sweden Member No.: 17,452 Region Association: Scandinavia ![]() |
Some of you may have read my earlier pleas for help when my engine suddenly would not start. I thought it was the FI but after following the advice of members I did a compression and leak down test and discovered Zero compression and 100% leakage on #2.
With a heavy heart I pulled the engine, the pictures say it all. I had the heads rebuilt earlier this year and have not done more than 300 miles. (IMG:style_emoticons/default/mad.gif) Some questions: what else needs to be checked for damage? I need some new heads does anyone have some ready to use heads for a 75 2.0? I guess the piston is also unusable, if I get some aftermarket P&C can I just install them without replacing the bushings on the connecting rods? I guess the summer will be over before the engine is fixed. (IMG:http://www.914world.com/bbs2/uploads_offsite/i1300.photobucket.com-17452-1436869957.1.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/i1300.photobucket.com-17452-1436869958.2.jpg) |
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falcor75 |
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#2
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia ![]() ![]() |
Aow that really sucks (IMG:style_emoticons/default/sad.gif)
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wndsrfr |
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#3
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,430 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region ![]() ![]() |
Looks to me that you should get the valve seat replaced, buff out the dimple in the piston and get back on the road for the remaining three weeks of your summer....then do more extensive work later.
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billh1963 |
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#4
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Car Hoarder! ![]() ![]() ![]() ![]() Group: Members Posts: 3,402 Joined: 28-March 11 From: South Carolina Member No.: 12,871 Region Association: South East States ![]() |
I would like to think that the piston is okay....but that's the optimist speaking (IMG:style_emoticons/default/smile.gif)
Any chance the piston could be cracked or any damage to the rod or crank? If the piston was soft enough I guess it could absorb the worst of the impact without transferring that shock through the rest of the motor? |
EdwardBlume |
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#5
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914 Wizard ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 12,338 Joined: 2-January 03 From: SLO Member No.: 81 Region Association: Central California ![]() ![]() |
What a bummer, but at least you are going for it! (IMG:style_emoticons/default/aktion035.gif)
Good luck with the rebuild! |
Cairo94507 |
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#6
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Michael ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,796 Joined: 1-November 08 From: Auburn, CA Member No.: 9,712 Region Association: Northern California ![]() ![]() |
Oh no! That sucks beyond belief. I hope damage was minimal and is contained to just the head and piston top.
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Cj Honeycutt |
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#7
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Member ![]() ![]() Group: Members Posts: 50 Joined: 7-August 10 From: Fallbrook, CA Member No.: 12,020 Region Association: Southern California ![]() |
The pistons take a much worse pounding with each compression stroke than felt by that small ding. As long as timing, mixture, ..... thermostat,..... are all set correctly, you can just leave the P/C on, buff the top of the piston and get the heads done correctly. That problem if not initiated by some of the above wrong settings, is due to a bad valve job.
Spend the money and get them (do them both to avoid this problem again) done right. Here are the folks that know how and have worked with 914 heads and development of new heads for a very long time. Hoffman%20Automotive%20Machine,%20Inc.%20-%20VW%20Type%204%20Heads.webarchive. If link doesn't work, just look up "Hoffman automotive machine" |
cwpeden |
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#8
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Great White North, huh? ![]() ![]() ![]() Group: Members Posts: 916 Joined: 20-August 06 From: Victoria BC Member No.: 6,693 Region Association: Canada ![]() |
That doesn't look so bad. Head can be saved.
After 300 miles? That's a valve seat that wasn't installed correctly in the first place. And for it to happen on that cylinder just means the rest weren't far behind. Ditto on doing both heads. I suggest going to where you had them done and dropping them on the counter asking WTF? The last mechanic that f'd up one of my vehicles paid half the bill for someone else to do it right. |
914_teener |
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#9
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,200 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California ![]() |
That doesn't look so bad. Head can be saved. After 300 miles? That's a valve seat that wasn't installed correctly in the first place. And for it to happen on that cylinder just means the rest weren't far behind. Ditto on doing both heads. I suggest going to where you had them done and dropping them on the counter asking WTF? The last mechanic that f'd up one of my vehicles paid half the bill for someone else to do it right. (IMG:style_emoticons/default/agree.gif) |
Mark Henry |
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#10
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that's what I do! ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada ![]() |
When rebuilt was the seat replaced?
Seat looks odd, not only dropped, but also like it's broken. I agree that both the head and piston may be savable. |
Valy |
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#11
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,676 Joined: 6-April 10 From: Sunnyvale, CA Member No.: 11,573 Region Association: Northern California ![]() |
The piston is good, just buff the top.
The head needs work. If the valve seats were replaced, then the guy who did them did a bad job. If they were not replaced, did anyone checked them before assembly? A failure in 300 miles means that the seat was not fixed good at assembly time. If you need, I have a 2L head. I can send it to the local guy that did my heads and was top notch. |
screenguy914 |
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#12
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Member ![]() ![]() Group: Members Posts: 249 Joined: 6-July 09 From: So. Cal Member No.: 10,540 Region Association: Southern California ![]() |
Some here have pretty good observation skills to assume the piston is okay ("It'll buff out"). The hit was toward the periphery of the piston and the impact could have affected the ring lands below it. Have you inspected the piston yet and the resultant ring side clearances? If affected, the ring might be seized and thus unable hold compression to spec. But I'll admit, removing a piston is yet another stage in engine disassembly.
You could also just repair the heads and reassemble, but perform a compression test on the bench to confirm all is okay. MHO |
Cj Honeycutt |
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#13
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Member ![]() ![]() Group: Members Posts: 50 Joined: 7-August 10 From: Fallbrook, CA Member No.: 12,020 Region Association: Southern California ![]() |
The piston crown is designed to take much abuse. Shock waves and compound standing waves from pre-ignitiion. That is a small dent. I have seen MUCH, MCUH worse damage to piston crowns were seat went to shrapnel and embedded in piston crown. Piston and ring land still perfect.
Good advise though to take the barrel off and inspect the piston if for no other reason than it is easy at this point and will give peace of mind to confirm it is completely OK NOTE: Cracks start at the surface, so the smoother the transitions are made when buffing the stronger the crown will remain. IMHO |
whitetwinturbo |
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#14
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Honey, does this wing make my ass look fat? ![]() ![]() ![]() Group: Members Posts: 1,391 Joined: 22-October 11 From: Newport Beach/Kalefornya/USA Member No.: 13,704 Region Association: Southern California ![]() |
.......................unless the pins holding the rod to the piston was weakened and separates from the piston under some stress/overrev and then (IMG:style_emoticons/default/blowup.gif) ?
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Cj Honeycutt |
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#15
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Member ![]() ![]() Group: Members Posts: 50 Joined: 7-August 10 From: Fallbrook, CA Member No.: 12,020 Region Association: Southern California ![]() |
The piston pin is THE most robust part of the entire engine other than perhaps the flywheel !
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DavidSweden |
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#16
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Member ![]() ![]() Group: Members Posts: 479 Joined: 8-June 14 From: Sweden Member No.: 17,452 Region Association: Scandinavia ![]() |
The piston crown is designed to take much abuse. Shock waves and compound standing waves from pre-ignitiion. That is a small dent. I have seen MUCH, MCUH worse damage to piston crowns were seat went to shrapnel and embedded in piston crown. Piston and ring land still perfect. Good advise though to take the barrel off and inspect the piston if for no other reason than it is easy at this point and will give peace of mind to confirm it is completely OK NOTE: Cracks start at the surface, so the smoother the transitions are made when buffing the stronger the crown will remain. IMHO Here is a close up of the Piston. The damage is about 2mm deep at the deepest point. Many have said that this will buff out. Is it just a case of smoothing the edges to the damaged area, what do members think is the piston usable? (IMG:http://www.914world.com/bbs2/uploads_offsite/i1300.photobucket.com-17452-1437152916.1.jpg) |
rfinegan |
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#17
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Senior Member ![]() ![]() ![]() Group: Members Posts: 973 Joined: 8-February 13 From: NC Member No.: 15,499 Region Association: MidAtlantic Region ![]() ![]() |
If the lands are not damaged then blending the edges of the damaged area to reduce the chance of preignition is in order and by the looks of the pic it appears that it will be ok. No need to "buff it out" but blending yes
_Robert |
veekry9 |
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#18
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OldMember ![]() ![]() ![]() ![]() Group: Retired Members Posts: 3,068 Joined: 17-June 13 From: TO Member No.: 16,025 Region Association: Canada ![]() |
Buff?
Nah,Pull the cylinders,check the rod for bending,rod bearings for damage,rod bolts for cracks,crank for damage. A hole in the crankcase may result otherwise. (IMG:style_emoticons/default/biggrin.gif) |
Dave_Darling |
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#19
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914 Idiot ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California ![]() ![]() |
Send BOTH HEADS to Len at HAM. One intake seat came out; the others will be relatively soon. Don't ask how I know this.
--DD |
McMark |
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#20
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914 Freak! ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None ![]() |
Safe way: check everything
Fast way: leave the cylinder alone The gouge in the Piston is nothing. Don't even think about that. You don't run high enough compression for it to matter. There is very likely no damage to the rest of the components. But realize that there is some risk to ignoring it. |
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