Cast Iron Timing Cover?

Saw one pop up on eBay. Seller claims "These prime faster, have higher oil pressure, leak less and wear five times longer. Cast iron expands from the gears less when the engine is hot and if it gets smacked by a thrown rock, it's not going to bust like aluminum."

I can understand the rock part, but is there much "weight" to the rest of his argument? I'm trying to keep the engine reasonably light but he's got my attention...

 

Think might be a 300 size only cover.

 

It was an industrial/Marine cover. More common with 225 oddfire V6. May have been used on 300's in boats.

 

A lot of Mercury I/O drives used Buick V6s. Yes, there are advantages to cast iron.

 

I had actually bought one on Ebay A few years ago and after researching it they were used on marine engines and the water passages were different than A car so I canceled my order.

 

Ohh ok. So what destroys normal covers? All I've seen is the scoring from the water pump impeller. Does any amount of scoring render the cover unusable?

 

Steel gears eat the aluminum over time. Change your oil every 3000 miles and it may never happen. But guess how many actually did?

 

I always use the booster plate. Either T/A or Melling.

 

What would have been nice is an iron liner inside the pump cavity

 

So the booster plate protects the cover from the water pump?

 

No, the booster plate goes between the oil filter adapter, and the oil pump.

 

I had a local guy bring one in. It was on the 350 in his boat. We cleaned it up and did the oil pump assembly on it.

 

That’s cool, but the only advantage I can see is the oil pump being an iron cavity, betcha it’s heavy

 

So what is different about the marine engine? Why would the water passages need to be different?

 

The water passages aren't different, you can see they're the same in the pictures above. A marine engine pumps water from whatever body of tater that the boat is in (fresh or salt) through the engine for cooling, aka no additives to prevent corrosion like in automotive coolant. Therefore an aluminum timing cover would fail fairly quickly if not properly cared for, where the iron would be more resilient.

It also helps with regards to the oil pump clearances since the iron cover will expand and contract less than an aluminum would with water temperature fluctuations. Say you drive the boat, stop for a bit, the water in the engine heats up, then you start it up and immediately cold water is flushed through the engine.

 

hmmmm . interesting . sure heavier but seems a lot more durable .
edit - used one $200 . so not terribly out of line price wise if in very nice shape . especially considering it's a marine part . one thing they mentioned was to watch out for the salt water use versions .

 

The one's I have seen aren't set up for the water bypass, the small line that goes from the thermostat housing to the back of the cover. I think that was the concern I had when I was thinking about buying one.

 

I remembered what the difference is.