Money shift., Help me figure this out. Options

[ottox914]

A friend of mine, whom I would trust with my life or my wife, was taking the 914 for a little test beating with me the other day. At about 7k rpm and 15 psi he money shifted me from 3rd to 2nd. He WAS very quick to throw the clutch back in, but...

I now need a new fan belt, as the OEM one was thrown and is slightly mangled at present. More concerning, is the noise it makes now. It isn't the 1 in 4 cycle "thump, thump" of a rod bearing. I can pull plug wires and rev it up and the sound remains. Its more of a tic-tic-tic-tic-tic thing. Due to the speed of the tic tic tic and that it goes up and down with rpm, I'm thinking valves. Not that i really want to think that.

Any other thoughts or trouble shooting to be tried that anyone else can think of?

I'm thinking to start with compression test, move to leakdown, and submit some of the oil for testing of metallic ick. I can do the compression test and send in the oil, but I don't have the tools for the leakdow.

[Mike Bellis]

Never let anyone drive a turbo 914. (IMG:style_emoticons/default/sad.gif)

[rick 918-S]

Wow! Sorry to here. Maybe it dropped a seat. Use a long screw driver up to your ear and touch the engine around each cylinder. Maybe you can locate the cylinder and start there.

['73-914kid]

(IMG:style_emoticons/default/stromberg.gif)
I'm sorry to hear that someone else may have messed up that engine.. That is my biggest fear of letting other people driving my car, and my biggest fear driving someone else car..

[messix]

bent valve

[r_towle]

A friend of mine, whom I would trust with my life or my wife, was taking the 914 for a little test beating with me the other day. At about 7k rpm and 15 psi he money shifted me from 3rd to 2nd. He WAS very quick to throw the clutch back in, but...

I now need a new fan belt, as the OEM one was thrown and is slightly mangled at present. More concerning, is the noise it makes now. It isn't the 1 in 4 cycle "thump, thump" of a rod bearing. I can pull plug wires and rev it up and the sound remains. Its more of a tic-tic-tic-tic-tic thing. Due to the speed of the tic tic tic and that it goes up and down with rpm, I'm thinking valves. Not that i really want to think that.

Any other thoughts or trouble shooting to be tried that anyone else can think of?

I'm thinking to start with compression test, move to leakdown, and submit some of the oil for testing of metallic ick. I can do the compression test and send in the oil, but I don't have the tools for the leakdow.

Use a compression tester threaded hose hooked up to a 125 psi compressor in each cylinder.
Listen with a hose to your ear and the intake, exhaust and oil filler holes for sound.....you can hear it right through a muffler pipe if it's leaking and you can hear well enough...

[ottox914]

Use a compression tester threaded hose hooked up to a 125 psi compressor in each cylinder.
Listen with a hose to your ear and the intake, exhaust and oil filler holes for sound.....you can hear it right through a muffler pipe if it's leaking and you can hear well enough...

I can probably rig something up. I thought the "right" way to do this was with gauges and such, to measure the rate of leakdown. I get how this process would at least identify leaking at the valve, and which valve it might be. Don't I need to have the motor at TDC with both valves closed, and them find some way to "lock" it in that position, so the pressure of the air does not push the piston down and rotate everything, opening a valve? Any BTDT to set this process up and get it right? I'd hate to do it wrong, think I have a bunch of bad valves, rip it all apart and find a simple fix rather than the valve thing.

Should I be able to visually inspect the head for other damages, or if I can see the bent valve just replace it and be good enough. I put a bunch of $$$ and Len put a bunch of time into those heads... they were perfect.

[ottox914]

Wow! Sorry to here. Maybe it dropped a seat. Use a long screw driver up to your ear and touch the engine around each cylinder. Maybe you can locate the cylinder and start there.

Tried that from the top side, but my screwdriver wasn't quite long enough. I know, that sounds more like a personal problem, but it is what it is... are you thinking from the under the car, where I can get at the actual motor, and not just the tin? I would think the tin would to a degree "share" the tic-tic-tic between cylinders, so I might be able to narrow it down to one side sounding different from the other, but maybe not narrow it to a specific hole. I could always pull the valve covers and rotate the motor and watch the valve stems to see if one or more is that far out of whack.

I'd like to think we didn't do any MORE damage, we drove it back the 3-4 miles to my house at low speeds and low rpm's.

I didn't think our motors were interference. But I never thought about that when Jake, Len, and myself were spec'ing out the configuration of this motor.

[76-914]

Use a compression tester threaded hose hooked up to a 125 psi compressor in each cylinder.
Listen with a hose to your ear and the intake, exhaust and oil filler holes for sound.....you can hear it right through a muffler pipe if it's leaking and you can hear well enough...

I can probably rig something up. I thought the "right" way to do this was with gauges and such, to measure the rate of leakdown. I get how this process would at least identify leaking at the valve, and which valve it might be. Don't I need to have the motor at TDC with both valves closed, and them find some way to "lock" it in that position, so the pressure of the air does not push the piston down and rotate everything, opening a valve? Any BTDT to set this process up and get it right? I'd hate to do it wrong, think I have a bunch of bad valves, rip it all apart and find a simple fix rather than the valve thing.

Should I be able to visually inspect the head for other damages, or if I can see the bent valve just replace it and be good enough. I put a bunch of $$$ and Len put a bunch of time into those heads... they were perfect.

Harbor Freight has one that is pretty good and cheap. Towle is right in his method but if you want to know the percentage of leak down you will need gages. If looking for the bent valve you wouldn't need gages. Listen thru exhaust for the bent exhaust valve and thru the TB for an intake valve. (IMG:style_emoticons/default/beerchug.gif)

[Jake Raby]

There's nothing good about "zinging" an engine. If it was zinged at 7K that hard it HAS to come all apart to be inspected and to have the rod bolts replaced (at minimum).

It doesn't matter how long it was at max rev during the "zing" what matters is how fast it achieved that RPM. Missing a shift at 7K was sure to send that engine to a minimum of 8,500 RPM and maybe even higher.

That engine has valve control to around 8K RPM, but you can't assume that the rest of its not hurt afar such an experience.

This isn't hat you wanted to hear, but its what you needed to hear.. If you assume that it just has bent valves and you address them, you'll probably learn something the hard way later..

Just like I did. You won't assume twice.

[SirAndy]

Money shift

I added a constant reminder to my custom tach face ...
(IMG:style_emoticons/default/shades.gif)

(IMG:http://www.914world.com/bbs2/uploads/post-179-1241070704.jpg)

[infraredcalvin]

My buddy has several race cars with a crude version of that with a label maker. His engine builder refreshes the $$$ sticker every rebuild. (IMG:style_emoticons/default/lol-2.gif)

[Mike Bellis]

Money shift

I added a constant reminder to my custom tach face ...
(IMG:style_emoticons/default/shades.gif)

(IMG:http://www.914world.com/bbs2/uploads/post-179-1241070704.jpg)

I think you're missing a couple $$... (IMG:style_emoticons/default/poke.gif)

[SirAndy]

I think you're missing a couple $$... (IMG:style_emoticons/default/poke.gif)

One is enough as a reminder... (IMG:style_emoticons/default/poke.gif)

[ottox914]

Going to check out the car tomorrow. Still don't really want to know, but need to know, you know? Think I'll pull the plugs and see how they look, and then pull the valve covers, turn the motor over, and see if there is any obvious valve weirdness going on.

Any other thoughts on a fairly quick way to figure whats going on?

[messix]

for some reason I thought you had a six.... if it's a 4 check to see if the rocker towers are loose, it might have pushed the studs out a bit and now you have excessive valve lash. you can readjust the valves but you will have to fix the stud issue still.

['73-914kid]

Figure out which valves are loose by pulling the valve covers and going around with a feeler gauge. I would check to see which valves are loose, loosen the adjusters, and check the rocker mounting studs to make sure they're tight like messix mentioned. If that is verified as being alright, I would pull out the pushrods, and make sure they're still perfectly straight. A friend over-revved a type 1 on downshift, and it spun to the moon (built to be non-interference) and all it did was bend pushrods..


I agree with Jake though, I would not longer trust the rod bolts any longer after zinging an engine that high.

[ottox914]

Onward with the auto-topsy. Heads will be on the way to Len the head-master who built them for me. From pics, he was hopeful, but we'll have to see what the Head Doctor has to say once he has metal on his operating table. I saved the oil and took a closer look. I drained off 90% of what was in the pan, and swirled the balance around like a gold prospector. Sadly, if all the shiny bits I saw in the bottom of the pan were gold and not copper, I'd have plenty of funding for the replacement motor. But alas, that much copper is bad 2x. Its not gold, and it tells me the bearings are likely toast. I can only hope the case, crank, and rods can be saved. Have a busy couple weeks coming up with work and house projects, so it'll be awhile till I can get the case split. I'll know more then.

[gms]

Money shift

I added a constant reminder to my custom tach face ...
(IMG:style_emoticons/default/shades.gif)

(IMG:http://www.914world.com/bbs2/uploads/post-179-1241070704.jpg)

I love it!

[Cuda911]

^^^ Me too! Would love that tach face.