240 vs Hardbody Block

[jiffyp20]

I'm a noob so don't be too hard on me, thanks. Anyway, doing a stock rebuild ka24e for daily driver. I have a block from a 240 fresh from the machine shop, and of course the original truck engine about to be removed, 1990 227k dropped valve. Trying to decide which one to build. I know the 240 uses the crank girdle and the truck doesn't, but I guess the real question is what would you guys do?

[seang]

opinions vary

[jiffyp20]

From what I've read it's too much trouble. I'm just going to rebuild the one in the truck. Anything special about the ka? I've only dealt with chevy small blocks in the past.

Thanks

[seang]

It is way smaller than a small block chevy. The timing chain guides should be replaced with metal ones like the later engines (96-97 Pickups) have from the factory. Other than that, the stock pistons are the next weak link but only if you are going to use a turbo. Pretty good motor for what it is: forged crank, forged rods, very durable camshaft and lifter friction surfaces.

[jiffyp20]

Interesting, I thought the timing chain guides for sale were all 'corrected'. I replaced the timing chain setup a while back, but I ordered the parts for a 1990, but it was plastic with metal backing I thought. My dad bought it new, said he had to take it in shortly thereafter because of the startup noise. So I assumed nissan had realized the problem early on and weren't replacing them with the same faulty parts, but I've been wrong plenty of times :-P Going to keep it stock. Got the engine out and onto the stand, haven't started digging into it yet. I'll post some pics of the chain and guides and stuff.

[seang]

My truck is a 97 with the metal backed guides and it still makes noise for a few seconds on startup, but it is not wearing through. If plastic guides wear through, the chain will start to ride on the aluminum timing cover, and eventually eat through that into a coolant passage. If that happens you have oil mixed with the coolant and a big mess.

[jiffyp20]

Here is a pic of Cyl 1. It's a little overflashed, but you can see the "clean" portion. More pics on that site. I'll get the ones of the timing chain and guides up tommorrow.