'71 198 swap to a '76 225 - help identifying noise?

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GFlo

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The original 198 in my '71 Valiant lost cylinder #6, so we found a decent '76 225 and swapped it in today. Mounts were different and there was a bunch of additional emissions stuff which we removed, but otherwise went pretty darn well! These engines are so straightforward, love it!

Anyways... it is making a slight noise / tick. Can any highly trained ear out there point me in the right direction? Don't think it's simple exhaust leak.

 
Maybe check the converter bolts.
 
The original 198 in my '71 Valiant lost cylinder #6, so we found a decent '76 225 and swapped it in today. Mounts were different and there was a bunch of additional emissions stuff which we removed, but otherwise went pretty darn well! These engines are so straightforward, love it!

Anyways... it is making a slight noise / tick. Can any highly trained ear out there point me in the right direction? Don't think it's simple exhaust leak.


You do know the rods out of that 198 motor are worth saving. Even if only 5 of them are still good. There is always a market for the 198 rods.
 
Maybe check the converter bolts.

Torqued them all to 22 ft-lbs per spec.

You do know the rods out of that 198 motor are worth saving. Even if only 5 of them are still good. There is always a market for the 198 rods.

Yes, the long rods are desirable, I do know. Any idea what a set would be worth? I was just going to sell the whole engine and let someone else dig them out. Don't have a ton of time right now.
 
Torqued them all to 22 ft-lbs per spec.



Yes, the long rods are desirable, I do know. Any idea what a set would be worth? I was just going to sell the whole engine and let someone else dig them out. Don't have a ton of time right now.

Not a ton. They need to be reworked and new rod bolts installed for any performance application. I'd give 150 dollars for some but that'd be about it. You figure 150 plus another 150 to have them resized, another 75 for good rod bolts. A little more and you can get the Molnar and K1 rods.
 
Yeah, 198’s are kinda cool and different. Needed to get it back up and running ASAP for the Woodward Dream Cruise and swapping in a 225 was easier and faster. Also, 13% more displacement never hurts :)

And the ‘76 we got has hardened exhaust seats so that’s a plus.
 
sounds like something is puffing? Gasket? Spray the sealing part with WATER and see if anything changes or bubbles up. Add a little dishsoap in there so it will bubble over an air leak. remember under the carb too, its a huge source of exhaust leaks. If it has an aluminum intake, check for cracking of the heat stove under the carb, itll give you a massive vacuum leak. And of course check the valve lash.
 
Front tin dust cover on bellhousing rubbing on crank/converter.

While running, touch cover and you should feel it.

Those covers can be very challenging to straighten, - many end up frisbees across the yard.
Good luck !
 
Front tin dust cover on bellhousing rubbing on crank/converter.

While running, touch cover and you should feel it.

Those covers can be very challenging to straighten, - many end up frisbees across the yard.
Good luck !

Yup, when first started it was making a terrible racket and I suspected the bellhousing cover. Removed it and that noise disappeared, leaving this other less severe noise.

So is the bellhousing cover even necessary? I don’t drive it a ton - rarely in the rain and never in the winter.
 
Found it! Pulled the dipstick and the noise went away. No amount of bending the dipstick or putting it in a different orientation changed it, so just left it out. Dumb thing!

Anyways, the thin flimsy bellhousing cover is off since that was rubbing too. Can I leave it off? Is it really that critical?
 
Found it! Pulled the dipstick and the noise went away. No amount of bending the dipstick or putting it in a different orientation changed it, so just left it out. Dumb thing!

Anyways, the thin flimsy bellhousing cover is off since that was rubbing too. Can I leave it off? Is it really that critical?
The bellhousing cover is really designed to keep dirt & water out of the area. You can certainly drive the car without it, but long term it should be installed.
 
Dipstick....who knew! :)

Yeah, turns out it’s relatively common. The dipstick passes really close to the crankshaft, so if they are even slightly bent in the wrong spot the crank hits it. Not a great design.
 
Yeah, turns out it’s relatively common. The dipstick passes really close to the crankshaft, so if they are even slightly bent in the wrong spot the crank hits it. Not a great design.

I had the same issue. Hey it's a 4" crank! Crank actually kicked the dipstick up out of its seat.
Bent the bottom a bit and no more noise. Knock on wood!
 
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