084 Engine

[Stackem]

Is a used 084 engine worth 200.00? The guy said it runs.

[chuckitt]

Hey Stackem, Thanks for joining the mini forum. I have bought 9 of these engines and they were as is. 5 of them are running motors. 4 of them will be used for parts. If it turns over good and you feel compression on each cylinder, it will probably run OK. It is worth the 200.00. If you don't buy it and the seller is close by, I will buy it.
Where are you located?
Thanks, Chuck

Ron & Robins 084 with belt drive.

Papee's 084, Direct Drive

[buster]

I could use a bit of tech info on my 084 engine. The engine was purchased used at a gov't surplus auction, and I suspect it had an oil pressure problem. I took the cover plate off the oil pump, and both gears look fine, so then I unscrewed the oil pressure regulator valve. The only parts I found were the plug with the gasket around it, and the spring. It seems like there should be more parts than that. The military Tech manuel does not show a picture of the parts, it just says to clean, inspect, and replace defective parts! Are there more parts inside, and if so, how do I get them to come out?

If needed, where do I get replacement parts? Saturn Surplus does not have these parts listed on their website.

The reasons I suspect an oil pressure problem is that we took out the plugs and spun it over about thirty seconds with the starter-generator. The oil pressure gauge didn't move. Also, when I got it, the oil lines to the filter were unhooked, the filter adaptor was missing, as was the low oil pressure shutdown transmitter.

Before anyone asks, the oil had been drained, but I did refill it, and also filled the new filter, before we started.

Appreciate any help,
Thanks, Dave

[Duane Scarborough]

Buster,

I suggest that you join the Yahoo A084Experimentors group, and post your question there. Those guys use the 4A084 in experimental aircraft, so most of thier topics are aircraft related. There are some very experienced 4A084 builders there, and I'm sure they can answer all of your engine questions.

I found a local guy there who builds Electronic Fuel Injection systems for the 4A084. Its fairly expensive though, and we don't need it as much as they do in aircraft. After talking with Ron Paxson on Saturday, seeing and hearing his engine, I'm going to go with a Solex carb when I get far enough along to need it.

Duane

[buster]

Duane,

If I don't get an answer here, or figure it out myself, I may do that in a few days. My problem shouldn't be that hard to diagnois, except I'm not very familiar with an 084 engine yet. Also, that military tech manuel is all but useless. Anyway, thanks for that suggestion.

I was talked into using a Solex carb by my buddy. He has been rebuilding and messing around with VW's ever since we were both building Dune Buggies in the sixty's. He has rebuilt dozens of them. It's a good, budget carb that's easy to work on, and modify.

Dave

[Duane Scarborough]

Dave,

I agree about the simplicity of a Solex. My experience with one 30+ years ago on a Dune Buggy, and Ron's recent experience on his 4A084 has me convinced. The Solex is a carb tinkerer's dream.

You can buy a brand new "modern" one with the electric choke and the fuel shutoff solenoid for about $165 almost anywhere. Or you can shop the junkyards for a good used one....

Here's a picture of Ron's, on his boat. It had no hesitation at all when he ran the engine for me. (on the trailer) When he went half throttle, I thought he was going to push his van out of the parking lot.



Duane

[chuckitt]

Hey Buster, There is one more part in the oil pressure regulator. There is a plunger after the spring. I think you can view the info at this site.
http://www.tpub.com/content/operator...9-14/index.htm
Try it and find 4-41. it will show the parts. If your motor is missing the plunger, i have some junk motors i could rob one from.
Thanks, Chuck

[buster]

Chuck,

I did find one more part, It was the plunger, and it was stuck good, in the end of the hole. We made a tool, and finally worked it out. It had tiny scratches on it, and I figure it got jammed with dirt or whatever. That must be what the whole problem was. I guess Ill just blow it out the best I can, and put it back together.

I figured on rebuilding the o84, or replacing it with a new one over the winter anyway. Hope it will run for this summer!

Also, If you sell "rub rails", what do they cost? I will need almost thirty feet.

Dave

[chuckitt]

Hey buster, I will talk to Marty today and see what the rub rail will cost. The rub rail we use on the mini's. IT is 1.25 inch but i think you can make it work. Thanks, Chuck

[buster]

Thanks Chuck,

I'm sure I can get it to work. I can't find anything narrower, and I need to use something.

Also, now that I got a working starter, I put my oil pressure relief valve, and oil pump back together, and gave it a spin. It turned over about fifteen seconds, until the oil press gauge started moving, but It seems to be OK now.

Thanks for your info,
Dave

[buster]

What's with all the oil leaks on this engine??? I realize the 084 is bought is a used engine that needed some TLC, but now it seems to run darn good.
The problem is just about every place there is a seal or gasket, it is seeping oil.

I doubt it has yet run an hour yet, and the bottom of the boat looks like our garage floor when we owned GM cars.

I intend to go through that engine this winter and take care of all the questionable areas, but is it normal to have this many oil leaks in an 084?

Dave

[Papee]

I looked back at my engine the other day when I was running it and my fuel pump was doing the jiggle. I stopped right away and tightened it back up. I have no leaks on mine now for a year other than a push rod tube after I replaced the cylinder and didn't have the retainer spring on right. I hate to see oil on the rudders when I come in. Just be careful, those bolts seem to be soft. I broke off 2 when I was trying to get the valve cover leak stopped. Luckily there was enough there to get hold of to get them out. I haven't put any lock tite on mine because I want to replace the rest of the cyls this winter. I think Chuck put some new ones on when I got the motor from him.

[buster]

Papee,

Among other places,mine is leaking from three out of four block to cylinder gaskets. But when I replaced #2 head, the cyl. had no ridge or groves or scratches. It was like new. Can't say what the others are like, but I think I'll borrow a boroscope and check them out.

If yours is that dry, maybe mine will stay dry for a while if I replace some of those gaskets and seals, I hope. As it is, my rudders will never rust

I am not sure which bolts it is that you said are "soft", or did you mean all of them? I had better watch out for that, sometimes I tend to get a bit aggressive.

Thanks, Dave

[airhead]

Buster,

Are you sure the engine is breathing good? It sounds odd to have that kind of problem. Even if the engine has a lot of blow by it should be coming from the breather. If you haven't already; check the breather. I don't know how it comes out, I haven't checked mine yet. Also the one that connects to the air cleaner, i feel like this one needs to be at least open or even better, vented to the air intake. Just some thoughts. I hate to see you have this problem.

Jim

[Papee]

The ones I have noticed are the valve cover and oil pan bolts. I broke the valve cover ones.

[buster]

Airhead,

I think it is breathing OK, one breather is near the top on the timing cover, and I have not hooked anything to it yet. It blows oil out against the back of the drivers seat. There is one other breather near the back end, and I'll check that one out too.

Papee,

I'll watch out for those bolts. So far I have just been using a screwdriver on them, since they have a slot. I'll be dealing with the oil pan soon, 'cuzz I have a number of leaks there also.

Thanks, Dave

[Papee]

If you need a random gasket let me know, I may have it. I bought a whole set when I did my heads. I know I have the oil pan gasket but no Valve Cover ones left I was using The blue RTV sealer but changed to the regular brown sealer on mine.

[buster]

Papee,

Thanks for that offer, I'll keep it in mind. I also bought a complete set when I only needed a few, but I may need more than I have when I re-do my engine later on. But you let me know if you need one, I may have that.

Dave

[airhead]

Buster,

I checked the little mushroom breather on my engine this afternoon. It screws in the block and takes a 3/4 inch wrench to remove it. I couldn't get it to budge but if i was having your problem it would come out one way or the other. The only thing i could tell is that it has a screen on the bottom and cannot tell if it is packed or not. Yours might come out easier. I just can't believe your engine is worn out if it runs good and don't smoke etc...

Jim

[buster]

Airhead,

At your suggestion, I intend to check out the mushroom shaped breather tomorrow. I've seen it there but never thought about it.

I really don't think my engine is "worn out". I am starting to think that someone that didn't know what he was doing, worked on it before I bought it. For one thing, when I first put oil back in it, I found the flywheel had been installed without an oil seal in place! Oil started running across the floor right away.

I'll just have to go through it and check out everything. I am wondering if there even is an oil pan gasket in it.

Thanks, Dave