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2001 motor home 440

levicah

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Shelton, WA
Ok, this is where my ignorance will really shine!
1rst, what would cause a vertical 32th" wide divet the length of the cylinder? was it caused by a stuck/ broken ring gap, or is it a worn sleeve gap from a previous repair? only one cyl. looks like this. Otherwise, I cant tell if there is a sleeve in there.
2nd, top of #1 bore is 4.355, bottom is 4.335 Piston is 4.316 I believe.

It's been 14 yrs since I mic'ed the bores. I believe these are averages taken from various sides of the bore.

Real question is, whats a deal breaker for rebuilding a thin wall motor home 440? Should I just toss it, or can I re bore it at all? Is it worth sleeving etc?
 
I’ve never seen a thin wall block. You should have it magged and sonic checked before making any decisions.
 
I'm curious how a motorhome built in 2001 has a 440 in it.
 
It's about 40 years since the last 440 rolled off the line- has this motor been rebuilt- I ask because there are a lot of low mileage motorhomes out there and some with the wheels run off
Real motorhome motors would have different plugs and cooling holes in the head and block (and gasket) next to the plugs with raised ribs in the casting to permit the holes
Real Motorhomes had premium valves -- SIL-Xb intakes and Inconel exhausts- really pricey to replace but they are usually reusable
check the numbers on your motor and let us know if you have the cooling holes
how much overbore will it take to clean up the block?
how's the timing chain and sprockets?
sleeve works fine if you can find someone in WA to do it- where's Shelton? I have a place in Bellingham but do not know of any shops
anyone else?
 
Many diesel engines are sleeved and they run REAL high compression. I would sleeve and engine if another wasn't so easy to find.
 
The scratch could be caused by any piece of metal that got into the cylinder...piece of a piston ring, chunk off a valve, a small nut dropped down the carburetor, etc.

I think the last 440's were built in 1978...maybe later for an industrial engine. Are you sure it's a 440?

As for the block, you're choice. Sleeve the one bad hole if it does have the extra cooling passages & the correct motor home heads, otherwise, I'd probably find a different block....unless you can sleeve one hole & reuse the stock pistons...my 2 cents
 
sleeves do not have seams- they are one piece
LA sleeve near where I am makes good ones- Whittier- Santa Fe Springs CA
 
Excuse me. "pulled" from a motorhome in 2001. Residual stocks of 78' 440's found their way into 1982 motorhomes. Yes it's a 440. It has been a stripped block for 14 yrs, sprayed in oil and buried in my garage. Awaiting response, I have learned about the thin wall myth. Contrary to some indignant responses here...this wasnt common knowledge 14+ years ago. Variations in alloy strength contributed to the myth. I like the broken bit of piston ring hypothesis beekeeper, for the vertical cylinder scarring. I didnt know if sleeves were seamed, so thank you for that wyrmrider. So nobody wants to give me a max bore size for a 440 engine. So, is it .20 or .30 above the factory bore size? I just wanted to know if it was boreable at the above mentioned diameters. I didnt want to spend for diagnostics on a engine that was too far gone.
 
... So nobody wants to give me a max bore size for a 440 engine. So, is it .20 or .30 above the factory bore size? I just wanted to know if it was boreable at the above mentioned diameters. I didnt want to spend for diagnostics on a engine that was too far gone...
I'm hot-rodding around in a .040 over '73 440, if that helps...we recently restored my uncles '68 GTX/440 and that block easily went to .040 as well. Like 5.7 posted above .060 isn't out of the question but sonic checking is really good insurance, especially if the block is already stripped down and just hangin' around. Then you will know for sure. Check prices aroud you, it's usually not too expensive. Unfortunately there just isn't a standard 'max bore size' number that can be considered safe for every engine.
 
I'm hot-rodding around in a .040 over '73 440, if that helps...we recently restored my uncles '68 GTX/440 and that block easily went to .040 as well. Like 5.7 posted above .060 isn't out of the question but sonic checking is really good insurance, especially if the block is already stripped down and just hangin' around. Then you will know for sure. Check prices aroud you, it's usually not too expensive. Unfortunately there just isn't a standard 'max bore size' number that can be considered safe for every engine.


Cool! that makes a lot of sense to me, Thank you, also 5.7hemi!
 
0.060 Pistons are readily available but as said, you need to sonic check. Lot of core shift in some of these blocks. Some guys have taken them 65 or 70 over but that’s really pushing it and you need custom Pistons anyway as far as I know.

But I think more importantly, if it’s only one bore it makes no sense to take the entire block it out to 60. You are probably better off taking the block to 20 or 30 and sleeving the one hole.

Heck the rest of the holes might only need to hone and rering
 
60 over is 4.380, 60 over 400 size (.080 over 440) 4.4 and 4.375 all common sizes (for rings) but just do the minimum you have to do and check piston and ring availability before you do more than clean up that one hole
hard to measure how deep a gouge is but you can get close
to sleeve a 440 is not hard-- What HT just said sure sleeve one back to std if possible
 
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