1300 converted to 1600 makes "ratty"noise during excelleration

[fifthcenturycheese]

I am trying a used 1300 that has been converted to a 1600 in my bug. The history on the engine is that it was taken out of a car by the German mechanic that performed the services on it. It's an F0 case with bigger cans added later, a 113 905 205K along with a brazilian solex 30/31 carb. I put a new repop Wolfsburg West muffler on but am having a hard time getting the exhaust donuts to sinch up tight enough to stop exhaust leaks. Everything concerning the exhaust system aligns properly, but still having minor leak issues. What is troubling to me is the engine or car makes a "deep ratty" kinda sound under load/ when accellerating or going up hill....the more gas I give it, that "rattier" the sound. ??? Timing was set at 7.5 advance for that particular distributor. What the hell is the sound? Thanks for taking the time to read this, Mike.

[Pruneman99]

Might be detonation. You need to see how much total advance your getting. IDK if that carb is the right match with that distributor. You might be getting the totally wrong vac signal.

In wouldn't drive it until you make sure it's not detonation or you might be rebuilding that engine again quicker than you think.

[fifthcenturycheese]

I forgot to mention, it has popped/sputtered coming down hill in gear as well....

[iowegian]

I have no idea what a rat sounds like, but perhaps you are merely hearing your exhaust leaks.

[h~moto]

What kind a air filter is on your car? An engine without an air filter or a filter less restrictive than normal would make a sound that I would describe as ratty.

[fifthcenturycheese]

Stock 67 air cleaner.

[bluebus86]

[Rome]

[Zundfolge1432]

Keep the throotle to the poodle

[fifthcenturycheese]

So, I adjusted the Brosol/Solex H30/31 according to the Rob and Dave's page of carb adjusting. Did exactly as they listed and the car idles nicely at around 900 rpm. Where the heater boxes fit into the new aftermarket muffler, I was getting the exhaust leak "ticking/hissing" sounds. The new exhaust seal donuts and clamps were not pulling the gaps together so I cut some Coors light can material to fill in the gap between the donut and smaller diameter exhaust pipe...that seemed to get rid of the leaks! Simply going tighter with those clamps was not working. At this point I will ask that the beer snobs keep to themselves on the Coors Light business.....

The "ratty" sound as I call it... It is hard to describe a noise, maybe better would be a more solid rumbling when under load, going up hill and heavier acceleration when driving. The best I can do is a solid kind of gargling sound and vibration towards the back end of the car. I know I need to replace the rubber "body to chassis " pads that insulate the body from engine and road vibration. I know what detonation from fuel breaking down sounds like and this is a deeper sound than "pinging".

There is no paperwork on the 1300 to 1600 conversion work form the past so I would probably have to pull a head to see what size can is in there. I can't find the head number at the moment, but it seemed that I looked it up and they were 1600 sp heads.

Still getting the ratty noise, runs better with adjusted carb and quiet exhaust seals. Still slightly snaps when going downhill with car in gear, foot off throttle...

Still trying to diagnose ratty sound and eliminate....

[67rustavenger]

The exhaust "doughnut" clamps are not the same size front to back. When you have a new set you have to look carefully with them layed on a flat surface. You'll notice that the front side of the clamp is smaller than the rear (front meaning the front of the car).
The smaller side is the heat-exchanger side of the clamp. Put the doughnut metal backing ring on the exchanger first then the doughnut. Slide those rearward into the flared inlet on the muffler then install the clamp smaller diameter on the exchanger and larger on the flared muffler. It should seal up well if the parts are in the correct orientation. No beer can band-aid needed

Good Luck.
_________________
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There's never enough time to do it right the first time. But there's always enough time to do it thrice.
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[fifthcenturycheese]

There's a new twist to this engine! Did a compression test on the cylinders and found: #1 at 125psi, #2 at 135psi, #3 at 85psi, #4 at 130psi.

As you can see, I have a dead cylinder. First thing I am going to do is check the torque on the head bolts. If that doesn't produce a miracle, I will then do a cylinder leak down test to find the source of the problem.

I am slowly learning about all of this and want to figure out how to correct this issue. If its just a valve or a set of rings, can just those components be changed? How do you figure out sizes and all. Or is it cheaper to just get a set of heads?

Thanks for following this post and all your help, Mike

[Q-Dog]

Some parts can be repaired or refurbished without too much expense, some are better replaced. Find the issue first, then you can deal with how to repair it.
_________________
Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle