Chevy 7.4 Big block

[chevywontmove]

Hi Everyone.
I am stuck !! I took on a project Chevy P30 Coachman last year for a re-furb a top end engine rebuild. The re-furb is fine but i am stuck with the engine. Apparently the engine overheated and the heads were gone. I purchased the correct heads,new gaskets set(s) and put it back together . All turned fine and smooth apart from a backfire and not starting. One day after messing with the timing,engine backfired loudly,stopped to crank and made a horrible (machine gun )noise which then became an almost metal on metal grinding to a halt noise ?? (almost like a boat that had grounded ?) Luckily it was only on turn over and not running but does anyone have a clue or may have heard similar. I am NOT a mechanic but have limited knowledge. I have started to strip the top end as it seemed the noise was there but any suggestions please ?
Thank you in anticipation .
I'm in Leeds if anyone can help !!

 

[Ikonix853]

I would suggest the r/chevy sub on Reddit or Pistonheads. Did the engine have oil in it? Was it primed prior to starting so lifters had oil? Have you taken off the oil pan to check for damage and parts? What do the lifters look like? By messing with timing do you mean moving the distributor or altering the camshaft? Did block get machined and if so did pushrods get measured for fit after?
That is just a few but I would go ask experts on Chevy Reddit as they will know exactly how to fix it...they will work better with photos.
Apologies I can't help properly

 

[Burgo]

Dropped a valve?

 

[gus-lopez]

 

[chevywontmove]

I'M hoping so ! . Hopefully when i remove the heads something maybe in there ? Albeit so far it all looks ok ! I am really hoping that it is nothing in the bottom end as i have no idea how to even start with that ! Top end is all quite easy to follow !
Thank you for your help

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[chevywontmove]

Thank you Gus , If you don't want to help then don't comment x

 

[Geo]

Thank you Gus , If you don't want to help then don't comment x

Hope you enjoy your short stay on here.

 

[Lenny HB]

Thank you Gus , If you don't want to help then don't comment x

That was uncalled for, someone welcomes you to the forum and you can do is be rude to them.
Goodbye.

 

[chevywontmove]

Sorry GUS-Lopez Said to his friend in Spanish
"Never leave someone alive that you don't turn your back on "
In Spanish
"Nunca dejes vivo a alguien a quien no le des la espalda" To quote .
This was his reply to me ?
Have i missed something or should i be expecting a short stay on the forum as you suggest ? I was only asking for help with my motorhome ?

 

[monzer]

Sorry GUS-Lopez Said to his friend in Spanish
"Never leave someone alive that you don't turn your back on "
In Spanish
"Nunca dejes vivo a alguien a quien no le des la espalda" To quote .
This was his reply to me ?
Have i missed something or should i be expecting a short stay on the forum as you suggest ? I was only asking for help with my motorhome ?

I'm not sure but Gus does talk about guns and shooting people quite a lot so I'd be careful

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[chevywontmove]

AHHH ! I HVE MISSED IT !!! SO SORRY XXX
I missed the WELCOME bit (DOH !)
I reacted to his message underneath the Welcome bit and had a knee jerk .... SO SORRY !!!
Iwill send a message now (Sorry everyone !)

 

[old-mo]

I was only asking for help with my motorhome ?

Shall we start again...???????????

If you go onto this section = https://www.motorhomefun.co.uk/forum/forums/introduce-yourself.7/

You could introduce yourself and say I have a problem with my Chevvy and a question I have put in/on "motor Home Section" I would like answered should some one have an answer.. please...

 

[old-mo]

If you get really stuck... give these guy`s a call =
ABM Automotive
Icen Ln
Weymouth
DT3 5PY
United Kingdom

What Adi don`t know about yank engines aint worth knowing. This is his web site = http://www.abmstarters.co.uk/

Or another contender nearer to you is = http://www.motorhomemedics.com/

They used to do all my work on various yanks..

Then Adi opened up in Weymouth..

 

[Ikonix853]

Hi again, I note you have another thread for this as well. Mention in that one that you took distributor out. If so did it go all the way back in as that is what drives the oil pump on some chevy's?
Take the rocker covers off, if it is bone dry in there then no oil so this engine will need stripped, as oil galley goes to rockers, pushrods, lifters, cam and crank bearings. Hopefully it is something easier than that though!

 

[Burgo]

I note you have another thread for this as well. Mention in that one that you took distributor out. If so did it go all the way back in as that is what drives the o

It'd be really hard to miss, and really 'out thete' but if the distributor hadn't been put back all the way in / the drive helix gear was stripped, and the drive slipped that could cause backfire as spark timing would becout and a rattle as it slipped. Grasping at straws dept, that one, I know!

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[bobandjanie]

I know nothing about American RV's but Duncan and Chris at Star Spangled Spanner, are great knowledgeable helpful people.

Security measure

www.starspangledspanner.co.uk

Oh and you could ask on the sister site. https://www.rvoc.co.uk/forum/

Bob.