Yesterday just before getting home I heard a click from the engine then again. It wasn't steady, just every little bit I would hear it. I could feel that I lost power and it even stalled once at a stop light. Since I was only a couple block from home I just keep going.

I found that cylinder 3 could only produce 20 lbs of compression. A leak down test was 22% with most air coming out of the intake. For reference the other cylinders were 100 to 105 compression and the leak down was 18% to 20% with air noticed just in the oil filler hole. I don't know how accurate my testing tools are since they are cheap ones I got from amazon and harbor freight.

I took off of my valve cover for cylinders 3 and 4 and with cylinder 3 at TDC I have over 1/2 inch of play with both valves and the pushrods are of course way loose. I haven't removed the rockers to pull the pushrods out yet to see if they are bent. I will do that after I pulling the engine either tomorrow or this weekend.

How screwed am I? Thoughts on best and worse case?

Here's a video of my loose rocker Video of rockers

you may have dropped a valve seat which will wedge against the head and hold the valve down open.

Rich

I will check for that. That doesn't sound too bad unless the piston hit the valve and bent it.

Unfortunately, it's probably best to start saving $$$$ for a pair of new cylinder heads and potentially a set of new P&C's. A dropped valve seat or broken valve will likely ruin the piston on #3.

i agree its likely dropped valve seat,that #3 is the most common cylinder, it happened to me 2 years ago, and they dont always cause damage, mind didnt and i had my OEM heads sent out and rebuild with all new stuff, including upgraded new valve seats, new valves, guides springs etc. BUT you might be better off getting new head castings and ahve the same done to them. see what you have once you drop the motor . you can scope it , pull the plug and get an idea if thats the case but, you might as well drop the motor .

Phil

914sgofast2, what is P&C's? Pistons and cylinders?

DRPHIL914, Who did you send your heads to? Was it less than buying new heads? I order a scope last night. I might pull the heads off before it gets here though. The motor's coming out tomorrow.

Who makes a good quality head that's reasonably priced? If I do one side, do I need to do the other as well?

I agree!


The other side is now suspect to happen soon
Rebuild time I’m guessing

@slapshot

i had a guy in Oregon that is a porsche and VW motor builder for many years do the heads, they can inspect them and make sure they are worth it but i would lean toward just getting new ones, due the heat fatigue to the metal , warping, cracking etc. i can PM you James's info, Ims sure also in Oregon Ben from Martin Mid-engine that used to work with Cary can both get you new heads and build them too.
Regarding the source of heads, the castings are new and come from AA i believe but you want bare castings with no hardware, so they then can be built up with quality parts.
Places like Stoddards, Sierra Madre etc can get those heads to but they sell them already built but not with the best parts.

Phil -
PS oh, i think its going to cost about $2500-$3500 for that depeding on the builder and how the heads ar spec'd. bare heads probably under $1,000

Phil

End result, to me, is a complete rebuild and EVERY thing else that gets done while you’re in there. Starting with any case work. It gets expensive. Quickly.

Who built the failing heads?

There just are not many skilled air cooled heads guys left

Thanks for all the information.

I've only had the car 10 months so I don't have all the info on the engine. The did give me the receipts for maintenance they had. The heads were redone in 2011 by Foreign Auto parts & Service in ST George, UT.

What I've found today after removing the engine and the tin around the head, the one of the rocker bolts appears to have blown out. A look through the spark plug hole shows nothing shinny but I'll see more when my scope comes. The valve pushrods are fine. I've got to research how this happened and if it can be repaired.

Hoping that is the only issue and can be fix and able to drive the car again.
Probably over tighten that made it broke.

Looks like the engine was “rebuilt” by GEX. Go over to the Samba.com website and check out the Bay Window Forum by searching for GEX engines. GEX is the most reviled engine “rebuilder” on planet Earth. ☠️☠️☠️☠️ is the GEX kiss of death. Start saving money now because this episode is likely the first of many to come.

Thanks for the positive outlook.

I retapped the bolt, put the rocker back on and set the gaps. Going to put it back in the car tomorrow. As long as the bolt holds, everything should be back to normal. I'd say that the reason I had no compression on that cylinder was due to the valve not getting pushed open and since the leak down test was descent the valve seat should be okay.

Did the retapped stud hold the correct torque ? ,looks like the other one has been helicoiled or some other insert.
Good luck with this ,sorry to say but you are going to need it,cheers.

I torqued them to 10ft/lbs. I put the engine back in today check compression and leak down before I started it. Compress was 95 and leak down was 22%. I started it up and it idle great and revving the engines was as well. It didn't seem to have its normal power while driving. I wasn't pushing it at all but could still tell something is still off. It seemed like it was running rich and missing a bit. After I got back I rechecked compression and leak down on all cylinders while still hot. Compression was, starting on cylinder 1: 102, 105, 100, 105. Leak down was 14, 18, 21, 16. That's normal for my engine since I got it. From that I think the engine is fine. Am I missing something?

Next steps is rechecking the timing which I've set not too long ago. I have a 009 distributor with a comp-u-fire module and dual DCNF Webers. Setting time is something I'm not comfortable with. It just doesn't seem to work the same as what I read in the manual. It leaves me scratching my head.

After that I'll go through the carbs again. It did seem to run rich on the test drive. It has never felt like that before. I had just got the car running good when the rocker blew. To get it to run good I had to step up to a 65 idle jet which is way big I know. It had 57.5 but backfired at idle and at 2500 RPMs. The car has had a high heating issue since I bought which I haven't solved. Maybe that rocker was screwing with my mixture enough to think I had to increase my idle fuel.

Excellant result if they held 10 ft/lbs you should be fine ,I ran 36DCNV's which were the last series made in the 80's so the most modern type of these,great carbs ,I don't remember the exact size of the idle jets but #52 rings a bell you may find yours are too big causing the back fires especially if you have poor response from the mixture screws .
I built some custom inlet manifolds and made up a linkage out of T4 carb parts ,bolted up and balanced they were a breeze to tune ,I never changed any jets but did fully rebuild them.
Cheers.

52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

Congratulations! thanks for the update too!

wow well im glad it was not a dropped valve seat, but with 2 of these having issues you might consider re-doing all of them, that just should not happen coming loose or breaking like that, but it sounds like you are getting good at dropping and reinstalling that motor!

Thanks for the info. It sure sounds like they are no good. The receipts I have show they bought these heads used. I'll get a better set when I do finally rebuild. Maybe over the winter. Good news, I think, I have verified I do have the original block. Its not all GEX.

DRPHIL914-- I am now fluent in dropping that sucker (4 times this year so far) and with many other things on this 914. I've never rebuilt an engine yet but that's coming. I'm dying to know what size pistons I have.

I thought I would give an update here just incase someone else runs into the same issue. I've been going on short drives almost every evening. Engine has been running good. I checked the valve clearances this morning and they were good. No signs that the rethreads are not going to hold.

Get your rocker gear sorted and then sort your carbs,those setting you are talking on the carbs are crazy ,when valves are done pull the top of one of the carbs and have a look in the fuel bowl ,if full of crap in the bottom I suspect you have blockages and a full clean and reseal will sort them ,and of course the favorite replies to supply are the following ;
what size vents and main jets,
is your fuel filter good ,
is your fuel tank clean and is the lower suction fuel gauze clean ,
old or new fuel,
what is your fuel pump and running pressure ,
etc as there will be more.
Best to answer the above as it will help you sort them,cheers.

I will open one soon and see what it looks like. It could only help to do a full cleaning. I'm going to pickup an ultrasonic cleaner and follow this guys cleaning DCNF Cleaning. Here's what I've got

Venturis: 30mm
Mains: 145
Idle Jets: 65
Airjets: 210
Emulsion Tube: F36

Thanks for the advice.