'74 2.0L Rebuild, Looking for advice Options

[ArtechnikA]

What would cause an intake valve to bend/br[ea]k???

almost always it's getting up-close and too-personal with a piston crown. >smack<

over-revving can do it - for which there are rev-limiting dizzy rotors (although the fact that the engines can't usually run into valve float rev-range on their own acts as a pretty good deterrent...) and there are things to do in the shifter department that keep you from tagging 2nd when you were trying for 4th in that freeway-speed downshift...

-maybe- if a valve step is -really- sticky from carbon, gum, sludge, and goo it could stick in its guide and be in the way when a piston comes by - but with flat-top 914 pistons you almost have to work at it. although - having clerances set up WAY too tight sets the stage for multiple ills ...

[mangrum]

Actually, it was the valve SEAT that dropped on my engine, not the valve itself.

I've heard this is a common occurance with these engines because of the location of #3 cylinder. It does not get as much air as the others and hence runs hotter. My engine had 120K miles and this seems to be around the time this happens. Happened on a '65 Bug I had at 113K.

[mangrum]

How do I tell if I need new valve springs?
Should I get stiffer/stronger ones?

[Bleyseng]

The dropped seat problem is because the engine is getting too hot. Usually this is caused by the engine running lean due to vacuum leaks from old hoses and seals.

Geoff

[mangrum]

I'm getting conflicting information on the big bore piston/cylinder kits. Are they worth the cost compared to the (minimal?) increase in power? 96mm bolt-on kits seem to run around $500.

I've also heard that they will cuase the FI to run rich. What mods to the FI would need to be done. Would this mean more $$$?

[Bleyseng]

Contact Brad about a set 96mm pistons and cylinders when he gets back. I heard he found a good source for them.
If you don't do head work the stock 043 MPS should be close, maybe a tad LEAN not rich. If you can find a stock 037 MPS, that would work better at they are richer straight out of the box.
I can also adjust one for you, if you have a good 043 unit, a tad richer.

Geoff

[mangrum]

Geoff, thanks for the info.

Is that Brad Roberts?

Brad, are you back? Can you tell me of a good source for 96mm pistons and cylinders?

I know this will sound like a stupid question to most but, what does MPS stand for? How do I find out if I have an 037 or 043?

Thanks.

[TheCabinetmaker]

manifold pressure sensor. Part # is stamped on it.

[Lotus914]

Broken valve - overrevving and 'floating', or improper adjustment, or broken spring.

Degreasing - I used ZEP CITRUS all purpose cleaner degreaser and a spraybottle from Home Depot and my wife's toothbrush. The citrus stuff works just as well and is much nicer smelling than brake cleaner, amnd seems not to hurt the rubber. Don't be fooled, it is just as nasty to the skin. Engine Tin off first for access, the plug the holes with rags, then CAREFULLY pressure wash it, the Citrus and toothbrush. Brake cleaner and nozzle to blast tapped holes and other tight bits. I'd think twice before using caustics on Aluminum. IIRC Oven cleaner is basically diluted caustic soda (potassium hydroxide) - frighteneing stuff which may attack aluminum. It may say on the label.

Here's how I cleaned the small bits - find two large tin tin cans, one of which just fits in the other, pepper the smaller one with small holes, like a colander. (I used a baby formula can and a juice can) Drop fasteners/parts in colander can and insert in big can, fill with varsol or whatever and let sit. Agitate occasionally so stuff can beat the grease off itself and crud can get flushed through holes to settle. Remove inner can and rest on angle on top of outer can to drain and dry.

Dave

[redshift]

CLR (crap lime rust) has a new oil removing product out that makes huge black oils spots disappear from cement.

I wonder if it would remove the engine?.. errr... grease..

(IMG:style_emoticons/default/smile.gif)


M

[mangrum]

I now have the motor dissasembled and most of the parts cleaned. While cleaning bolts, washers and nuts I was thinking "how am I going to know which ones go where?" Is there a reference that states size, type, material and location of bolts, washers and nuts?
Thanks.

[ArtechnikA]

I now have the motor dissasembled and most of the parts cleaned.  While cleaning bolts, washers and nuts I was thinking "how am I going to know which ones go where?"  Is there a reference that states size, type, material and location of bolts, washers and nuts?

there are the exploded parts diagrams available from various sources..

i suppose this probably isn't the time to mention that a excellent disassembly technique is to get a box of ZipLock sandwich bags and a box of business cards and record what the parts and fasteners are as you put them into the baggies ...

but this problem is why many (most?) professional mechanics hate dealing with the 'basket case' project...

at this point - check out the various manuals for reassembly instructions and try to match up every fastener with an associated step. i think there may be a copy of the 914 Parts Manual and its associated exploded diagrams and descriptions on the site somewhere - but someone else is going to have to post that - i donno where we hide them ...

[TheCabinetmaker]

How far did you go with the disasembly? Did you split the case, or just top end?

[72914S]

When I rebuilt my engine I saved peanut butter jars (plastic ) labled the lids for all the bolts,nuts and small parts. the rest into old milk crates.

[TheCabinetmaker]

When I rebuilt my engine I saved peanut butter jars (plastic ) labled the lids for all the bolts,nuts and small parts. the rest into old milk crates.

Rest of what into milk crates? We need details!

[72914S]

The pistons, jugs, rods and small engine tin pieces.The larger items,cam, heads,etc.wrapped it old sheets and put in a large rubber made container.All the F.I. pieces went into a large rubber made container ..but every plugin was labeled with masking tape as to their (IMG:style_emoticons/default/idea.gif) location.All hoses labeled and put into a large cardboard box,with a diagram of what it all looked like.Took pictures of everything as I took it apart. and notes, lots of notes.

[TheCabinetmaker]

ok, you have a place to start. Good job on the labeling. I do the same thing. Can you post pics of what you need to identify? The amount of a particular item can let know where it might go. The size, condition, color, might give a few hints.

Did you split the case?

[72914S]

the only pictures I have left are the before and after,the others got to dirty after rebuild to even keep.with the F.I. label all the hoses as to what went where then get new ones and match them up and label the replacments.label the wire harness,what plug goes to which injector. I did split the case,take pictures.Get a manual ..haynes worked for me.this web site ,Pelican ,Renn list; I even used a AUTO ATLANTA parts book to identify parts.

[mightyohm]

Are the 96mm p/c sets the suggested course of action now vs. boring out the 94's? I read on some old webpages that quality of the 96mm cylinders sucks.

I think I want to go 96mm on my 2.0 rebuild.

Also what is the preferred machine shop in the bay area to take my case, crank, rods, etc to have them checked out and rebuilt?