consultation - used 383 or motorhome 440 ?

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This is really long, but I'm hoping folks will read thru it all and give their opinions!

I have 2 'junkyard' engines here, I want to repair/prep one for future use. They've been sitting a long time. I've dug into both of them and don't know which one to pursue. I've always had good luck with used engines, never had to dig too far, so no experience with before/after of what I'm seeing on these.

Both of these were bought loose, and I'd never heard either one run.

Goal - get a decent-running backup engine, the stronger/tighter of the 2, with minimal cost (cannot justify rebuilding anything). Will replace timing set, perhaps oilpump (have both new on shelf), and new gaskets if I ever need to install into a car. FWIW, I am a fan of throttle response and mid-range torque, not high-RPM, full-throttle.

#1 is a '74 steel crank motorhome 440 (non-industrial, has standard heads and water housing), bought off ebay 10+ years ago.

#2 is a '68 383, reportedly a 4-barrel engine from a Sport Fury, but no way to confirm teh CR (not yet, anyway). Bought from a buddy that pulled it from a JY, he said it ran well. But been sitting for MANY years.

Both of these are good candidates for me as they have hte bosses on the block to fit in a 65 C-body's driverside motormount, are possibly drilled for 4-speed, and I have 2 1965 cars. (2 good candidates - too bad our presidential elections aren't that way)
 
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440:

Wouldn't turn over completely, found a stuck valve. Did an OP check and was 50+ psi, but had a lot of water in it (pure water, no AF). Discussed with a buddy, we believe hte water was only in the pan, and engine had not run with water in it. The water was clear enough that it seemed to be water collected while sitting, perhaps outside, but engine was remarkably clean inside for such a situation. I pulled a rod cap to look at a bearing and it looked fabulous, and crank looked really clean and smooth, no scratches. Either it never ran with water, or it did and this journal escaped unscathed. Removed heads to eval further -- 1 side had a steel gasket, other had a blue-type gasket, so soembody's been in here before. Pistons are approx .155" down, measured with a TDC bridge. I did not clean hte deck surface nor worry about where I hit hte piston - this was just a rough measurement, and all #s are within a .004" range, good enough for my purposes.

There seems to be some cross-hatch left, but some vertical marks also, the cylinder walls definitely aren't 'fresh'. Ridge is minmal, maybe .003-.004, barely catches a fingernail.

My concerns on this one are: the water, are there any cracks, the .155", and will it smoke like crazy?
 
383:

This engine turned over fine so I proceeded. It had a mashed-shut broken dipstick tube so I installed a new Mr Gasket chrome one and topped the oil off with some 5W oil-change oil (not gonna waste new oil in an engine that may prove to be junk). Got almost 50psi on the gauge but it started dropping down to 35 within about 15 secs of priming the pump with an elec drill. I assumed OK as it was thin oil and pressure still held around 30 (until my cheap elec drill started to get hot, as it usually does).

Got it runnign, it started pretty easily considering how long it sat, but it had lots of valvetrain noise (not unexpected) and after maybe 15 secs heard a little knocking so I shut it off. Was surprised to hear it; decided to let it cool (it has no water in it) and try again later. Had similar results on next startup - heard a little knock start after 15 secs so shut it down.

Next day I drained the oil to see if any clues and only about 2 qts came out. It turns out the dipstick markings were way off (lesson learned - never believe a new dipstick with an unknown volume of oil in the engine!) Fortunately no signs of metal in the oil. I put in 5 qts and repeated everything. Priming OP was good, didn't drop much, OP while running was good, VT noise gone, no knocking noise. (I fear I hurt it, but it knocked in only 2 incidents, only briefly, and only at idle, so probably OK?)

It starts and sounds pretty good, with only a slight 'chuffing' at the exhaust (it's got a Y-pipe, 3ft of flexpipe, and 2 mufflers in series). Vacuum gage (manifold vacuum) held around 18-20, might have floated around a little but no major wiggling or drops. Overall sounded really good considering a 440-tuned carb, used sparkplugs, and no 'polishing' whatsoever. It smokes only a little bit, and looks black, not blue, and only when goosing the throttle (carb and/or timing, probably). Felt good to proceed.

So I did a compression check. 140, 140, 145, 148, 152, 155 - and a 35 and a 0 psi. (the 2 low cylinders are same bank but NOT next to each other) Book-reading suggests the 35 is a valve issue, the zero a dead cylinder. But it doesn't sound like it has a dead miss, and it doesn't shake like it has one either. But it's sitting on a wooden cradle in a heavy steel cart on casters - maybe that's masking it?

I measured the cam, with a dial indicator on the lobes, and most measurements fall around .278"-.284" (seems to be spec for both 2 and 4-barrel cams), except for 2 lobes that are around .255" (I did those measurements a few times). Is this typical wear for a used cam? Would these measurements vary that much if I didn't measure consistently on the same spot on the taper?

If I pull the heads, I can see if it has a burned valve causing the 0 psi, and measure hte pistons in the hole to determine if a 2 or 4-barrel engine. (but I don't want to disassemble until I have a better idea which engine to pursue)

My concerns on this one: did the knocking hurt the bearings, why 2 low cylinder pressures, and is the cam too worn?
 
For whichever engine I continue on with:

I have a set of -516 heads from a rebuilt 383. The heads are VERY clean, nice gray color throughout, with new springs, and rocker arms/shafts were cleaned also. I do not know what hte quality level was on them, but I suspect this was a typical reman engine from a parts house.

I have a set of used -452s, came off an engine that I had running, condition unknown otherwise.



Questions:

If both were in good running order, would you use a STOCK low-CR motorhome 440 or the higher-CR 383?

If the 440 - use 452 for flow or 516s to get the CR up?

For either head on the 440 - use steel-shim gaskets or typical blue Fel-Pro?

Then, will teh 516 heads raise the CR enough that it'll detonate due to lack of quench? (I'm thinking not, as there's .155" + .020-.040" of gasket).

Did the little bit of knocking hurt the 383? Do I need to pull all the rod caps or is that overly-cautious due to running OK afterward with new oil?

If heads will fix my compression problem - use the 452 or the 516? If it's a 10:1 engine, will teh 516 be too much CR? (I ask this because I LOVE the throttle response of 383s with 516 heads).

Same question on this engine - which gaskets? Will thicker gaskets lower the CR but detonate due to poor quench?



Summary - which engine, which heads, which head gaskets?
 
You didn’t hurt anything with the knocking at idle. If you ran it for 15/seconds why did it have to cool? Always drain and refill to check real level of oil. The cam sounds Like it could be going away. Use the 516 heads and thin gaskets on either engine. I like 516 heads ALOT!
The 440 probably NOT drilled for a pilot bearing,

Remove the head on side of the 383 with low compression and inspect.
Is it the same side with the cam lobes smaller?
Bent valve or pushrod?
Bad rocker arm?
cam going flat?
Valves not closing or seating?

You tell us after checking into it.
 
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Thanks!
Was kinda thinking yanking 1 head was the 1st step for the 383, I'll see both low cylinders.
Cam lobes are #1 intake and #2 exhaust. The bad cylinders are #1 and #3.

More replies, please! :D
 
For the 383, two lobes at .255 effectively means that the cam is going flat and needs to be replaced. This is not enough wear to be causing the 0 compression, so the engine also is likely to have a stuck or burned valve. Either way the heads will need to come off. Before installing any used engine of unknown condition, it is a must to plasti-gauge the lower end. You do not want to have a bearing fail after going to all the work of installing an engine, do the job right once. The heads that are on the engine are going to have to come off, so figure out which heads are on the engine now. The piston height may be different than what is ideal for your other heads, this is important as the piston may sit too low to get proper combustion dynamics. Factory 2BBL engines were typically low compression and not a good candidate for a performance build. Your 383 has a steel crank which is a better choice if you are planning to run the engine at all hard.

For the 440. This is likely a cast iron crank engine and is externally balanced. Look at the harmonic balancer, if it is egged shaped or the bull nose type, the engine does not have a steel crank. That means you will need to find a weighted torque convertor to keep the engine in balance in a car application. It is also a low compression engine, so it is going to be down on power and not very fuel friendly. The properly tuned 383 will probably run better and get better fuel economy, so that would be my choice if these two are what I have to work with. As the 440 had water in the pan and signs of have been apart before, the head(s) are suspect, so if you decide to use those heads, be sure to have them checked by a machine shop.

Dave
 
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I kinda wondered if the 2 lobes were wearing into the hardening, but I think I'll measure again, paying more attention to where I'm at on the taper, see if the #s change. I have a decent new cam kit here, but don't want to install it right now as no good simple way to run it for 20min for a break-in.
Don't plan on running it hard, so either the 9.2 2-barrel or the 10:1 4-barrel would suit me, but 10:1 affects headgasket choice, probably.

The 440 has a steel-crank balancer on it, and I've heard that steels ran into motorhome engines into 74, perhaps later. Aside from the headgasket, it was all #s matching, carb and heads were both 1974. 1 head had a stuck valve, so not using them.

No machine shop work can go into either of these, I don't know who to use around here. I do have 1 spare/running '70 440, but does not have the bosses, hence my interest in one of these 2.
 
I kinda wondered if the 2 lobes were wearing into the hardening, but I think I'll measure again, paying more attention to where I'm at on the taper, see if the #s change. I have a decent new cam kit here, but don't want to install it right now as no good simple way to run it for 20min for a break-in.
Don't plan on running it hard, so either the 9.2 2-barrel or the 10:1 4-barrel would suit me, but 10:1 affects headgasket choice, probably.

The 440 has a steel-crank balancer on it, and I've heard that steels ran into motorhome engines into 74, perhaps later. Aside from the headgasket, it was all #s matching, carb and heads were both 1974. 1 head had a stuck valve, so not using them.

No machine shop work can go into either of these, I don't know who to use around here. I do have 1 spare/running '70 440, but does not have the bosses, hence my interest in one of these 2.

The 383 was designed for steel shim gaskets, the blue ones will drop the comp ratio about 1/2 point from where ever the engine started. 10.0 is a tad high to run with pump gas, so going to the thick gasket for a 9.5 ratio at which it should run ok on pump premium.

Dave
 
I find this discussion enlightening, as I have a 1977 RV 400 and a 1967 383 shortblock I copped for the steel crank for the 400. Mind you, the 400 will need to be torn down pretty thoroughly regardless for my plan, which is to build it with some 383 parts like the crank for a stronger, more durable one. I like internally balanced engines better on principle. I currently am running a 383 w 516 heads and a 2-barrel carb. I would like to build the 400 up for the same, which is how its constructed now, though I prefer the older Stromberg carb to the Holley on the 400.

I also have 906 heads from the 383, but for my purposes, I suspect the 452 heads would suit that 400 better, though the smaller valves of the 516 heads along with their closed chambers might be better....

I'll follow this discussion a bit as it throws a bit of light on my speculations....
 
Machine shop i used when i rebuilt my top end

"Jeff Edwards Racing" out in Brownsburg

317-908-8646

He bought all the equipment from the Brownsburg Napa when they got out of the machine shop side of things
 
Cubic inches are everything. You have to work on both so put the money toward the bigger engine. IMO

displacement.JPG
 
The 383 was designed for steel shim gaskets, the blue ones will drop the comp ratio about 1/2 point from where ever the engine started. 10.0 is a tad high to run with pump gas, so going to the thick gasket for a 9.5 ratio at which it should run ok on pump premium.

Dave
Good ballpark on the 1/2-point on the blues, I've got an old spreadsheet here that calcs CRs, I should've remembered to check that.

I find this discussion enlightening, as I have a 1977 RV 400 and a 1967 383 shortblock I copped for the steel crank for the 400....
FWIW, I replaced the worn 413HP in my 300L with a reman-but-used 400 with 452 heads. Some folks thought the closeness in CID, plus the higher flow of the 452 heads, would make for a comparable performer. Turned out to be so much different. I miss having the 413 in it. I'm contemplating that if this 383 runs well it would be better than the 400.

Machine shop i used when i rebuilt my top end
"Jeff Edwards Racing" out in Brownsburg

Thanks, I'll remember him if I ever do machining.

Cubic inches are everything. You have to work on both so put the money toward the bigger engine. IMO
Yeah, but in this case I'm thinking a higher-CR 383 might be a little snapper than a low-CR 440. And snap is what I'm looking for. Ultimately it boils down to 'which one is hurt less'.
Ideally I'd get one running, put in a car, swap heads to compare, swap in the other engine, swap heads again - but no time for all of that! And might need to then swap a prior one back in if it was the clear winner.:eek:
 
Does this pic tell anything about the quality of the bores? Forgot to attach earlier.
After cleaning with WD40 and a scuffy pad.
This is the 440 (383 is still assembled for now).

20190723_104018.jpg
 
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Good ballpark on the 1/2-point on the blues, I've got an old spreadsheet here that calcs CRs, I should've remembered to check that.

FWIW, I replaced the worn 413HP in my 300L with a reman-but-used 400 with 452 heads. Some folks thought the closeness in CID, plus the higher flow of the 452 heads, would make for a comparable performer. Turned out to be so much different. I miss having the 413 in it. I'm contemplating that if this 383 runs well it would be better than the 400.
r.:eek:

I wonder if the 452 heads would be a source of trouble in such a case. I have the 906 heads from that 383 short block, OR the 516s I'm running now. The closed combustion chamber might make the 516s the best option for a 2 barrel configuration, as they were designed to supply bottom end torque, while both the 906 and 452s, despite their larger valves, have open chambers.

Everyone I've spoken to around here (Tucson) reveres the 413. I suppose if one came my way for as little as I paid for the other 2, I'd be apt to snap it up.
 
.155 is waaay down in there. Bores look nice. A set of old TRW 6pack pistons and you would be in business. Compression with a mellow cam, and open chamber heads will just make a octane thirsty, detonation prone engine, high pressure, and no movement of the compressed gas on the up stroke, no thanks.
 
In my opinion build the 383.
It is a running engine (albeit not well but it runs) and the rebuild cost can be lower compared to modifying the smogger 440.
Put the 452 heads on the 383.
Makes the engine breathe better than the small valve 516's. 452 aleady have hardened seats so that alone is a cost savings at the machine shop.You will actually gain more torque despite dropping compression by half a point. That can be an advantage with todays quality corn fed gas pumps.
I am running 452's on the 383 4bbl 66 300 seedan. Gobs of torque . Runs 75 mph all day never overheats and drove to Carlisle 2016 at 18 MPG.
Hope this helps.
 
Barge - did you ever have 516s on that 66? Looking for some before/after comparison of heads.
I've had (and love) the snap of 65-67-style 383s with the 516s, never had a 906/452 version.
I am leaning toward the 383, as it is closer to being usable.
But by the time I am needing another engine, who knows, might have $$ for a stroker build, or might be into 5.7 Hemis, or ???

.155 is waaay down in there. Bores look nice.
Thanks for that feedback. As I mentioned earlier, I've never torn a used engine down this far, to see bores, to know what looks usable.
If I got taller pistons for it (then honed/ringed it) it would need balancing, correct?
 
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