Dirt Daily The Flatfender gets a Compression Test

Want to know if your engine is healthy? Give it a compression test. Its just one of the ways to figure out if the old Go Devil engine in the 1946 CJ2a is up for some trail wheeling. Today we'll get one step closer to seeing if our Jeep is ready to run.

[@bwstratn5516]

Run it a little bit and see if the compression comes up. Very little time and effort invested to find out if it really is toast. Those are very tough engines. Love the flatfender series.

[@upscaleshack]

So there are a few issues with your methods. First, don't put plugs back in the cylinder you just tested. Makes the starter work harder against compression and also means the engine is turning at a slower RPM each time you do this. By the time you reached #4 your battery was weak and the starter was fighting the compression of 3 cylinders. Notice that the manual states the PSI at a given RPM. It's a certainty that your test on #4 was not at the same RPM as #1. Second, open the throttle plate and prop it open with a screw driver. Or better yet, remove the carb altogether since you're probably going to have to rebuild it anyway. You want maximum incoming airflow into the engine for a compression test. With the PSI you have on the first 3 cylinders this engine will certainly run right now. Fire it up, get some heat cycles into it, and test it again and I'm sure #4 will improve. Don't spend anymore money on it until you hear it run because there's also a possibility of a spun bearing and rod knock on the bottom end.

[@jefflampe1760]

Great video, like others said, put a little Marvel down that hole. I marvel at the mysteries that stuff solves. Love this series, good job. 😂

[@xTinBenderX]

This video reminded me about the time I got a flat tire on my 73 Country Squire station wagon while off roading in DFW at 360 and Old Man Ed answered my CB call for help with his 42 Ford GPW and aired my tire with a Spark Plug Tire Inflator from his Jeep. He said it was a military issued tool. How a Spark Plug Tire Inflator works kzbin.info/www/bejne/oIW3h4mji8RgY9Usi=bzNI8Qgfy5ULwZKm

[@scottgalyk8970]

Nailed it

[@jean-pierrest-louis2830]

Vakve springs are upside down

[@TomsTinkeringandAdventures]

Sticky rings maybe, I would pick up some Yamaha Ring Free and try that. A leak down test would verify if it’s rings or possibly burnt valves.

[@davecamilleri9411]

try dumping some marvel mystery oil in the #4 hole and see if it frees up the rings.

[@regbale]

It’s a mystery. lol.

[@AnotherUnsociableOne]

Get it running and see if that cylinder maybe loosens up whatever is clogging the rings

[@gerry-p9x]

Yeah a few running. Heat cycles should loosen up the rings

[@christophersells9146]

Run it ...get it Hot...a few times..then See... Pluss your battery was getting weaker..you can hear it...pluss I would leave All the plugs out...for the whole test.. Your the Jeep Dude...Run..It!!!!

[@matthewspeller]

Bet it'll run fine once you get some heat into it. Hopefully just a stuck ring.

[@pdv76]

A bleed down test will let you know where the compression is escaping to. Or carefully use compressed air in number 4 cylinder and listen for air escaping past the valves or into the engine case on the power stroke. For the 4th graders, remember the crank can move once you start to compress any cylinder so keep fingers etc clear if you don’t have the piston at the bottom of the stroke. But like everyone said, if it needs a freshen up anyway no harm trying to get it to fire?

[@tb77073]

I’m thinking you get it running and those rings on number four are going to free up Love the Flat Fender

[@suparee]

Great content! Are you interested in sponsorship on vehicle lighting stuff?

[@sinkinpat]

My experience tells me to pull the valve cover and pull the head. When I started working on my 45 MB it started, ran, and bang. A piece of piston broke off and that piece did not compress and smashed into the head and broke my original to the engine Head. I wound up going thru 2 heads until I got one that would work. Pull the Head to inspect. It will make good KZbin content.

[@zellerjr]

Woo! More Flat Fender!!!

[@jessewilson117]

"It's it a waste of time? Yeah. But is it fun? Definitely!" Best quote ever!!

[@jbcowherder6210]

Suck..Squeeze...Bang...Blow.... gotta have all those things for the engine to make itself useful.

[@NotaRobot_gif]

You're really milking this one!! Video # 1,209,000 haha love the show brotha!!

[@matthewschneider2089]

Dude!!! Stuck ring? Get running, puts some heat in her!!! Then a hemi swap!!! Lol!!!✌️

[@b-lopez394]

Get the engine running and run a Berryman Products 2611 Intake Valve and Combustion Chamber Cleaner and see what happens.

[@jimbrazzell9316]

Razzel, Dazzel, Brazzell from OHI. Has anyone put a Pontiac Iron Duke four-cylinder engine in one?? I enjoy your show.

[@i976scirocco3]

If the engine is original, rebuild it. If not, Take the Best Body, frame, the New Engine/Trans/Transfer Case and make one Awesome Flat Fender from all your parts !

[@johnyhawgleg]

I’ve been watching for awhile on this particular project. Being that it had been stuck/seized. #4 was most likely the stuck cylinder this could account for the lower compression in that cylinder. Also like others have said. Your test is not entirely accurate. I do agree with getting it running and see if #4 comes back around. The rings may be a little sticky in the piston and a couple heat cycles might loosen them up. I definitely can’t wait to see the next video on this.

[@nobuddy4611]

With 25 psi it can never be a "stuck" valve not closing. That would always be 0 psi.

[@tylertkelley6779]

You are excellent @ explaining what you are doing to all! The compression over-all a little underwhelming, no?

[@jameshall4385]

I would fire it up. You might have bore taper and a ring is stuck in the piston groove. If you give it an Italian tune up it might come around.

[@leopom78]

That’s right Fred. Vice Grip Garage that Go Devil. Just rebuild the fuel make it happener. Then a feller might have a goin to town rig.

[@markbarnard1399]

These videos are perfect timing, as I'm working on my 48. I hope you replace the rings so I can see how you get the head off!

[@CalmTFD]

Either way you gotta pull the head to see what’s up. Just run it. If it sounds like hell after 20 seconds, shut it off and get ready to start tearing it down. If it starts running decent, 🙌🍺

[@rude235]

Could be a stuck ring. Maybe it will break loose. Fingers crossed!

[@clint4004]

Perfect for pulling it, dingle ball hone, valve lap and running....

[@Harey0407]

Get it running on 3, and let it warm up. Could just be a stuck piston ring is all, and some time and heat will fix it.

[@thomasdoddridge5389]

It would be blasphemy but a mercedes om616 or an om617 would be cool

[@ThunderRoad70]

Sometimes if the engine has been sitting or has been stuck the rings get stuck and can't expand to seal off the cylinder. If you run it a bit and burn out some of the carbon buildup it may loosen the rings and allow them to seal again. You probably already know all this anyway but I thought id share in case you didn't. Something else to try is substitute a quart of ATF type F with your engine oil and run it for a few hundred miles and change it. Ive had that trick work a few times on motors with low compression.

[@daviddillon6794]

Throttle should be held open full while cranking.

[@BIllMcCambridge]

I might've missed it but when testing make sure the throttle is held wide open and the exhaust pipe is not plugged.

[@danfay4860]

Spay a little mystery oil in each cylinder crank it over then let it sit a day or so. Could be sticky valves or piston rings

[@johnmccabe4596]

Some of your vavle springs are upside-down.

[@GLR6_]

Hey Fred when are you and dirt head Dave gonna get together again for cheap truck challenge or a trail ride?

[@nathanclay5798]

Great video topic and great comments in the comment section. Keep up the videos 👏

[@reddcocker64]

Fred, I'm with you on trying to get this one to run. Fuel and spark and see how it runs. Before pulling the engine, I think I would pull just the head and see what the #4 cylinder looks like as well as looking to see how the valves are seating. That will give you a better idea of how much of a rebuild you are in for before you pull the engine. Maybe it's just new rings and a dingle ball hone but if you see scoring in the cylinder walls, you know it's going to need more than a hone and some oversized pistons.

[@Jorqell]

Like others said: penetrating oil, get it running, and drive around a bit.

[@brianratliff6140]

Run it the rings may come around after a heat cycle or two. They are tuff.

[@RitzmanPerformanceMotorworks]

There's a whoooole lotta experts down here in the comments

[@JoseMartinez-tc9pr]

The little engine that couldn't. But have fun.

[@motownXJdad9565]

ive never see a CJ2 or 3 with a Jeep 2.5 with efi thats a combo id try just to keep it all jeep

[@johnmorrow5085]

Are you blind or just play a blind guy on you tube?

[@jwray9799]

Do a cylinder leak down test... see if air is coming out the crank case, (rings) or the intake/carburetor (intake valve ) Or the tail pipe ( exhaust valve )

[@redrampoly9321]

75% good or 3 quarters. That's a pass.

[@ronnie955i]

leak it down fred you're better that that

[@jonathanmoore7472]

Fred you need an M151A1 MUTT

[@CharlieRice-eq5hb]

I heard to open throttle wide open when checking compression.

[@MrMcgooOG]

How far has Fred gone down to.

[@pieissquared]

Keep plugging away at it

[@petervollers]

Great basic info Fred and very clearly explained.

[@petervollers]

Also funny that after all these years living in the west, you still say pool instead of pull. You can take the boy out of PA, but you can't take the PA out of the boy.

[@RadSalacan]

Maybe running it will knock those rings loose?

[@karmafarbus160]

LS time ! 😃

[@miniwolverine6227]

I would try to start the engine Fred, warm it up if possible, and then recheck the compression

[@amx19733]

That’s my upcoming weekend right there!!!! Excellent!!

[@Beat98TJ]

Time for a ford v8 flatfender!

[@ToddHavel]

Really enjoy the slow speed you are teaching us, explaining the thought process in a laid back way is very encouraging. Thank you for these troubleshooting skills you are projecting with our part time hobby!

[@darrinrebagliati5365]

My gut says WD/ATF/MMO the piston daily while putting the ignition and fuel systems together. Fire it up and get it warm a few times. The compression ring is siezed and needs a few shocks to loosen it up. 70 percent of factory isn't all that bad; it's not like it's a high performance engine in any case. If it's only 40hp max? That means it's still got 37 of them left!!

[@Mr-_-Leo]

Best robot dance ever!! Totally enjoying this Flat Fender series.

[@jawsdawg1]

I have 2 observations that may be helpful. 1.The engine rotation speed seemed slower as you went along . 2. At 16:44. That far right valve looked like it was closing really slowly. Perhaps a bit of penetrating oil in the #4 intake tract cound free the valve up in the guide.

[@Rivetroad]

Get it hot and make it work. The compression will come back they always do!

[@jasonmcdonaldhandmade7900]

I’ve done the rice or water down the carb to break up build up on the valves as the engine was running and have also just poured gas and oil mix in the cylinder and set it on fire and let heat up things. I’ve either had good result or no results. These were all old engines that have sat forever and and were believed to be no good anyway. All old timer tricks on engines that were old as dirt.

[@caseymuzio7609]

My favorite engine swap I've seen is a Mazda rotary in a flattie

[@nealesmith1873]

Probably should adjust the valves.

[@alans6767]

that is not a waste of time, you have to try to get it to run even if you already plan to swap it out

[@ferngullyfarm]

Jimmy Nylond may have the answer!

[@tchiggz9206]

Seafoam my friend

[@scottgalyk8970]

Just rebuild it

[@Babarudra]

no bueno!

[@dougsnova1]

head gasket maybe

[@4xFredWilliams]

that is a possibility too

[@reggiea2515]

Was this video made for 4th graders? “This is an engine, it’s made of metal..” 😆

[@4xFredWilliams]

yes it was reggie. gotta teach those kids how much fun jeeps are

[@nathanialcoleman1917]

I like to see people explaining the details of a project... yes at times in the video I myself was getting anxious and just wanted to see the results. But then I remembered that not everyone one knows this information and maybe it'll help educate someone. Maybe there is a 4th grader watching this who loves jeeps. And now knows just a little more. And today at school will be the cool kid talking about what he learned to his other 4th grader jeep buddies.

[@richardacheson9064]

Why did you put the #1 plug in.

[@4xFredWilliams]

i was getting excited to drive it!

[@jamesonpace726]

Yeah, a Japanese motor would be inappropriate, to say the least....

[@Kevin90909]

Rather than fix the problem, you want to keep fooling around with a broken engine....

[@Hillsautomotive]

Makes good content 🤷🏼‍♂️

[@j.danaclark2166]

That's the fun part! And sometimes the rings can be dry seized on the grooves and work loose with a few heat cycles.