Hi everyone, im trying to figure out what to do with the barth & would love to hear some opinions from other barth owners.
I have a 1986 25 ft. p30 454 barth. the motor is knocking, my cousin is mechanic & says its probably a main bearing. he pulled the plug wires 1 at a time while running & the knocking stopped when # 4 wire (I think) was pulled. im thinking I need to replace motor ??? what elese could it be ? would it be worth $$$ to replace motor ? also, cousin dont want the job and we drove it this way 300 miles to get home. thanks Bob

It ain't blown. So, fix it.

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Originally posted by crouch38:
my cousin is mechanic ...... he pulled the plug wires 1 at a time while running & the knocking stopped when # 4 wire (I think) was pulled.

That can burn up the coil or cause carbon tracking in the cap on an HEI. Best to check both. BTW, did the RPM drop the same amount when each wire was pulled?

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im thinking I need to replace motor ??? what else could it be ?

Rod bearing. Wrist pin. Broken or collapsed piston. Even a broken ring, with part of it moving up and down in the ring grooves.

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would it be worth $$$ to replace motor ?

A new motor is always nice, but you might be able to save this one by doing some checks first.

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also, cousin dont want the job and we drove it this way 300 miles to get home.

Did the knock get worse? How is the oil pressure?
How is the compression on all cylinders? Can you hear a poof poof at the exhaust? What does a vacuum gauge do? Can you find an old time mechanic who has an Allen Scope? Have you double checked the plug wire positions? 454s need new wires regularly, anyway. A particular form of mis-positioning has made a fool out of many a mechanic. A bad lifter can fool you, too. Pull the rocker pan and check clearances on number 4 rocker arms. Push down on each rocker arm at both ends (one at a time) with a hammer handle and see if the sound changes. Lay rags over the other rockers to avoid too much oil flying about. Some stores sell rocker arm drip shields (Lisle 35500) for doing this. Then, if nothing is found, I would drop the pan, pull one head and push the rod and piston out and have a look. If the crank journal and cylinder walls are OK, you could probably save it.

Agree with Bill H. Making it 300 miles you may have a chance to repair than replace this engine.

thanks for the trouble shooting tips. I allready drained the oil & will be removing the oil pan. first, to get the trans back far enough to make room for removal of pan. thanks again, Bob

Whoa, good luck on your project.

About a year ago I replaced the crankshaft in my 454. (Started out as a rear main seal repair!)

https://www.barthmobile.com/eve...1087061/m/5933940277

It is a major job working underneath but can be done. I have a tag axle so the coach body sits higher on the frame, you may want to raise your coach. Good luck!

Have Barth, will travel

quote:

Originally posted by Steve VW:

About a year ago I replaced the crankshaft in my 454. (Started out as a rear main seal repair!)

https://www.barthmobile.com/eve...1087061/m/5933940277

Having just read your whole thread on that, I must offer my compliments on the excellent write up and photos. You must have put in some long days doing that so quickly.

quote:

It is a major job working underneath but can be done. I have a tag axle so the coach body sits higher on the frame, you may want to raise your coach.

The frame rails (and engine) are the same height above the ground on all P30s. The tags have a higher floor in the cabin, but the cockpit floor is the same height above ground on all P30s.

Having said that, raising the frame rails on jack stands definitely makes things much handier. I did my engine swap from underneath.

I finally had time to work on the barth. I got everything removed to pull trans back out of the way. all trans bolts are loose but it wont come back.
it looks like I need to remove bolts that connect the flex plate to the torque converter, before trans will seperate from motor. then remove flex plate from motor. I never removed a trans before, so this is all new to me.

1. can someone tell me if this is right ?? or does it come apart a different way ??

2. if thats the correct way to remove it , whats the best way to rotate the flex plate to get to all the bolts ?? pull spark plugs so I can turn motor without compression ??

thanks again for all the help, Bob

Easiest way I know is to remove the bolts attaching the torque convertor to the flex plate, then the torque convertor will stay with the trans and you don't have to move the trans very far back. I was able to rotate the crank by putting a screwdriver in the holes in the flex plate to lever it around.



It is possible to just pull the trans waay back... this would leave the torque convertor still hanging on the flex plate and dump a bunch of ATF when the TC pulls out. (a real PITA)

BTW while you have the trans out you might want to change that front seal for the torque convertor. Just pull the TC out (with drain pan) to get to it. Saves having to pull trans later to change it when it eventually fails.





The oil pan can be removed without removing the flex plate but it is easier when the plate is gone.

Steve, thanks for the help. the pictures are great & help alot. I will try tomorrow. Bob

Just to update everyone . It's been 2 years & i finally got another engine . New GM 454 ho just like Steve's.
The new engine is sitting by the door inside the coach . Now to get started putting everything back together .
I got the old motor mounts out & see a # 357717 on them, but that # doesn't come up on a google search.


Does anyone know what the replacement part # is for the motor mounts ?

Also , What headers will fit the 454 with dual exhaust ?
I'm sure i'll have more questions later .
Thanks again everyone , Bob

I just found the part # 2395 for the motor mounts.
Can anyone verify this is it ?
Thanks , Bob

That is the mount that I used. Cheap but works fine. Good luck with your HO!

I will let you know when I get back to final tweaking on mine. I am still playing with timing, etc. I want to go back to dual exhaust and do the trans rebuild as well.

Thorley headers fit and work very well.

I hope your engine doesn't leak, you will like it.

Thanks for the quick response Steve.

Steve, Can you tell me the part # of the thorley headers that fit? Summit Racing says only headman headers will fit the p 30.
Thanks again . Bob