CJ7 junk yard parts bin on 42's

Not much for salvage yards around here, but I'm looking for a dead Volvo.

Also going to order this shorter viscous fan clutch and see if I can jam the dodge fan and shroud in this weekend.

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Other opportunities:
Holley carb is nice on the street but won't stay running on steepish ute stuff so its got to go before I even attempt west VA stuff

Trans won't stay in first gear. It just shifts to second like normal even with the gear selector in "1". Is that normal for a tf727? Maybe the accumulator piston or???

Went with thrush hush turbo mufflers. All 2.5" pipe but it's a cobbled together mess that I did in an hour or so before I left. Dumps out the muffler with a 45 right before the axle. Idle sounds great, cruise sounds great, but at trail rpm just above idle it's understandable drone. Maybe once I go over the axle and out the back with a crossover pipe it will go away???

Passenger valve cover leaks.

Other than overheat, needs a sniper, finish exhaust right, trans won't hold first, and valve cover gasket I'm satisfied with the project so far.
 
paradisePWoffrd said:
finishing the exhaust might help some, but i doubt it eliminates the drone. I would look into fitting a quarter wave resonator in there to eliminate the drone.
Click to expand...
^^FIRM believer in THIS^^
My old Mustang GT w/ OE shorties, Bassani X and MACs 2.5" single chambers out the back... droned so back it WOULD rattle your teeth! 🤬
Ran the numbers on the corral.com "1/4-wave length calculator" (engine "V" in degrees & drone RPM), got like 19.75", and a doubting artisan bud made/installed them (he eye-rolled and scoffed the *entire time*).
Was able to actually hear in it again!
He stood around afterwards trying to explain the wizardry, eating major crow, but did MANY more similar installs before retiring...
 
Alright wizards... I got issues. Doing the math on a 1/4 wave resonator at 900 rpm has the standing wave at 40-50 feet long.

Example:

900 rpm = 15rps. With dual exhaust I have 2 bangs per rev in each pipe so my noises are at 30Hz. Speed of sound at 300 degrees F is 1348 ft/s. So wavelength at 300 degrees is 48 ft. And the 1/4 wave resonator would have to be 12' long. I'm pretty good at cramming steel into this little jeep but I don't think that's going to work.

If I add a 6' crossover pipe then the bangs on opposite banks would cancel each other out. Don't have room for that. A 3' crossover pipe would be 90 degrees out of phase. That may be enough to take the edge off. Probably not... Could look into Helmholtz resonators, but I think the low revs will have the same affect on size
 
Clubbs said:
Alright wizards... I got issues. Doing the math on a 1/4 wave resonator at 900 rpm has the standing wave at 40-50 feet long.

Example:

900 rpm = 15rps. With dual exhaust I have 2 bangs per rev in each pipe so my noises are at 30Hz. Speed of sound at 300 degrees F is 1348 ft/s. So wavelength at 300 degrees is 48 ft. And the 1/4 wave resonator would have to be 12' long. I'm pretty good at cramming steel into this little jeep but I don't think that's going to work.

If I add a 6' crossover pipe then the bangs on opposite banks would cancel each other out. Don't have room for that. A 3' crossover pipe would be 90 degrees out of phase. That may be enough to take the edge off. Probably not... Could look into Helmholtz resonators, but I think the low revs will have the same affect on size
Click to expand...

Drone Freq Hz=(Drone rpm/60)*(# of cylinders/2)
Drone wave length=SOSmps/Drone Freq
Quarter wave tube length=Drone wave length/4+(applied 1/4 wave tube dia*.4)
Quarter wave Freq Hz=Drone Freq Hz*4

Where:
SOSmps = Speed of sound in meters per second and length output is in meters


(900rpm/60)*(8/2)=60RPS
@300F SOS=411.7m/s. 411.7/60=6.682m/rev
6.682/4 + (0.0635m*0.4)=1.6959m

Another option is to download a spectrum analyzer on your phone and record the drone frequency. Then do the rest of the calc.
 
I think that's the same math other than I'm using 4 cylinders since I'm running dual exhaust. I'll have a crossover pipe but not sure if I want to bother with the calc to add that in. I'll Probably just build it, use a sounds meter and see what the frequency is and go from there. May not be as bad once it's put together. As it is now I've got some dented flex pipe, clamps, and stitch welds holding in 10' of 2.5" pipe and a couple mufflers. Who knows maybe it sounds awesome if I actually finish it.

Hayden shorty fan clutch showed up today so I'll see if I can keep it cool first.
 
I'm currently running a $35 Jones Exhaust brand resonator on my Ranger. Right at the end of the tailpipe about 1' from the end. Used to drone terribly due to running just a chambered bullet muffler. With both, it's nice and quiet till you give it the beans.
 
Noel said:
I hear turbos help with the noise too 😎
Click to expand...
There's no way I can pack more steel under this hood, but I like the way you think.

I'll order a couple of Jody's silencer things.

An update on the cooling situation -

More wind:
IMG_20230805_112807756.jpg


More better:
IMG_20230805_114645272.jpg


Another win for old school mechanical another lose for girly man electric junk.
 
Pics from last weekend's let's see if this thing works or not URE run:

BJ almost flipped the runner -
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Found out the throttle cable needs more slack in it when the engine revved up right here:
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Couldn't get any steeper than this and the carb quit... That's not going to work. Only thing I miss about the old motor is the MPFI. Going to sniper the 440.
49055.jpeg
 
I must be internet ignorant... I can't find the dimensions on the nwf 205 integrated eco box. Seems there's some old info on pirate but I would need the 6 to 8 bolt adapter. Nwf's site has an option to select the 8 bolt pattern integrated so what am I missing? Does that come with an adapter or is it just drilled to use some of the 8 holes and leaves the rest unused???

Anyone got a detailed spec sheet on the integrated eco box? And how does it integrate to the 8 bolt pattern? Really need to know how long the thing is going to be...
 
Drove it to work today. 150 mile round trip. Stayed cool. Lots of power, it's ridiculous how light it feels. Cruises at 65-70 no problem, except it's windy with no top no doors so hung out around 60 most of the time.

Connected the msd box to the hesco tach and had rpms for about 10 minutes then nothing so must have burned that up... Oops.

Gets 8.5 mpg... great...

No overdrive, 4.56:1 gears and 35's makes for a thirsty rig. Need bigger street tires to get the revs down maybe.
 
Had a local exhaust shop put some pipes under it. Looks cobbled and he destroyed the header collector gasket so it now has that extra hp's sound :dumbass:. But the drone is completely gone probably from all the smashed bends so that's good.

Even so my son has been daily driving this rig to school for a couple months now (on the 35" mt "street tars"). Stays cool, oil pressure hangs in around 20 at idle when warm, lots of power, 9mpg, everything works - weird...

Well sort of. After sitting for 18 years the 49 year old valve stems have given up and she's chewing lots of oil so thats going to be a saturated afternoon coming up. And something is up with the voltage regulator, the gauge sits around 15.5 when running. If I put my meter on the batt it's mostly 15.5 but bounces rapidly between -3 to 17 volts. Got to be some severe interference in the wire going to the Regulator, but I can't figure it out, there's hardly a wire on this thing... How can it go negative???

Anyway, locked full width one ton big block CJ7 daily driver for my 17 year old plan is solid so far... I mean he drives 65 miles round trip to school so his fuel bill is easily a payment on a new, reliable, fuel efficient, girly man Passat with air conditioning, but we're raising men here. None of that practical modern sophisticated nonsense - big blocks rule. :driver: and insurance is cheap on the thing so it evens out - that's my story anyway.
 
My son and daughter inadvertently went off the road through a ditch and then back on the road through said ditch this week. There was a tree involved that wiped out the hardtop and may have been the cause of the front right leaf spring breaking. Everyone was fine, little shaken, probably going 35-40 and he somehow managed to not roll the thing (Divine Intervention I believe).

My daughter (13) said it was really pretty smooth and complimented my suspension design...

My son said he was surprised my welds held...

Both said the corbeaus and prp harnesses kept them in nice and tight.

Walked his route and really don't know how it didn't roll. Had it been my wife car or the ram it probably would have totalled them for frame / suspension damage plus the tree would have wrinkled
the roof and doors.

Other than the spring, hardtop, and passenger side mirror the CJ is fine. Well I got a trans pan leak cuz the driveshaft tapped it pretty good, but the long slip didn't fully compress and the front antiwrap bar saved the rest of the front end I think.
 
I build boats for a living and technically I could fiberglass the pieces back together, but it's not worth it. The rear gate was in good shape before this buts creased now so can't salvage that. I do have one good winder though - save on that Incase I blow one on the trail someday
 
Broken waggy spring. Oil on frame is from a previous valve cover gasket leak

52746.jpeg


Top sheared off at window line as one would expect. Still need to paint the cage...
52745.jpeg


Not the ditch they went through but this is across the road where they drug the top, note the passenger side top is missing several pieces...
52749.jpeg
 
Got new to us waggy springs and a new to us hardtop that is in excellent condition. Also ordered new spring bushings, new trans pan, valve stem seals, rear main seal, and all the other gaskets ya need to get those swapped out. Going to pull the motor over thanksgiving to reseal it (yes I know I should have done that before I put it in but I had a trail deadline).

Haven't touched it since the ditch situation. Hope to have it back on the road/trail after Thanksgiving.

Had the old 258 on the engine stand since the big block swap. Took the pan and head off just for grins. Number 2 piston was in 3 pieces and wedges at the top. Looks like it lifted the head hence the water in the oil. Rotated it backwards and it was pretty easy. Crank and rods all still together, and block could be bored and rebuilt. Threw it in the back of the truck and plan to scrap it with some other junk this week unless any of y'all want it...
 
Engine, trans and t case are out. He's pulling the intake off for a reseal here.
IMG_20231124_124809115.jpg


Main reason for pulling the whole thing was to check all frame welds and stop the oil leaks. This motor sat for 20 something years until this summer. Shoved it in the CJ and went for it without resealing. Started chewing oil pretty heavily. Suspected valve stems and that proved out. Only had 5 that were actually still there. The rest were gone...
53695.jpeg

This whole motor is crusty on the inside, buy maybe it's clean for 49 years old...

Blocking off the egr stuff, rear main, put the top parts back on, replace the trans pan that got smashed by the front shaft when the spring broke and then stabbing it back in, hopefully this weekend.

My back is sore for some reason, so not moving as fast as usual this time. Still enjoying time with my 17 year old, but balancing time with my bride and daughter is equally great, too bad they're not excited about vintage mopar big blocks and old CJ's...
 
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