7.4L top end refresh

[TitanTn]

Thanks for all the replies. I'm not really sure what I want to do. I don't mind rebuilding, but I don't like doing unnecessary work, nor do I like paying for work (parts) that doesn't need to be done. The oil pressure is good. About 55 once warmed up, and running at 2500 rpms. At idle it's about 35.

Of course I don't know if it's some kind of blockage in the pickup, wrong oil type (non zppd?), or exactly what. Again, I don't like replacing things that work fine, so I wouldn't be planning on changing the cam unless it needs it. From what I understand the lifters and push rods become matched after running together and if I replace the lifters I'll definitely need to replace the rods. I'm not sure if I need to replace the rocker arms, but perhaps.

I don't have a valve spring compressor and just don't have an interest in messing with valve guides, etc. I'd let a machine shop do a valve job, and anything else to the head that it needs.

I just don't see this engine as having a lot of wear (unsure of the actual hours, the previous owner suggested 400-500). It's all time and money. I plan on doing several other minor projects to the boat this winter and a complete rebuild wasn't really in the cards.

Again, thanks for all the thoughts. I'm still not sure if I really want to pull the whole engine or just focus on the top end for now. I guess the other thought is that if I ever legitimately need to work on the bottom end, I can pull the engine, do that work, and not worry about the top end.

[haugy]

I hear what you are saying. And it's a valid point. But lets say you do only the heads, and there is a small underlying problem that may have developed because of the ticking, or caused it. It's only going to happen again, or worse. You are planning to fix the ticking noise, but plan to also fix what's causing it if it's not just in the rocker arms and lifters.

Start with the heads, but make sure you spend the $$$ to get a proper head job. *snicker* A good shop will be able to give you an idea if your ticking came from the top end needing adjustment, or something in the bottom end causing it.

The reason I'd pull it is like Kevin mentioned, you could have god only knows what in your oil pickup. And unfortunately you can't just drop the pan like in your truck and take a peek.
Another thing mentioned is the timing chain, never hurts to take a good look at when you start pulling things off the engine. But I digress, as you can see I'm all about doing a full inspection.

I'll tell you one thing, take pictures, AND I MEAN LOTS OF PICTURES! Remove the valve covers, take pictures of everything, remove the intake, take pictures of the channels. Pull the heads, take pictures of each cylinder, the surface where the head meets the block, etc. They can be good for information or diagnosis later, and also so you can see what's different and what was actually changed.

[cadunkle]

At least pull the pan and check main and rod bearing condition. If good then you can button it back up, if not either replace bearings or turn the crank as required. Do a compression test first wet and dry to judge condition of rings. Easier to do while it's apart if it needs it. Personally I'd pull it apart and inspect crank journals and measure taper on the bores and do whatever is necessary, at least freshen up with rings and bearings if everything measures out. Parts are cheap if you don't need machine work and it'll already be apart.

WHile the heads are off I would port them. I'm not sure where to focus on BBC heads but as a general rule smooth the port and gasket match to intake and exhaust. Smooth the short turn to make it more gradual and also focus on the bowl. Smooth it and make channels pointing out the port. Look on some Chevy forums for 454 head porting, particularly find out where water is so you don't trash the heads. It's free power and economy so no reason not to do at least a minor cleanup.

If replacing lifters you'll need to replace the cam. Be sure to break in properly. Valvoline VR1, add Comp Cams or similar cam breakin lube. Pre-oil the engine until you've built pressure and turn it 1/4 turn at a time while priming. Immediately bring RPM above 2000 on startup and run at 200-2500 RPM for minimum 20-30 minutes, slowly vary RPM in that range periodically. After 20 mins do long slow pulls from 2000 RPM to 2500, then back to 2000, then 2000-3000, etc. continue the pulls incrementally through 4500 RPM or so then return to idle and adjust your idle and mixture and set timing. Watch for leaks and watch oil pressure during this process. Only shut down if there's a major leak you can't address while breaking in or if your oil pressure is not right. Pushrods if straight are fine, assuming your rocker geometry works out with the factory pushrods and whatever cam you run. Just roll them on a flat surface to ensure they're straight. Keep it mild, look at low duration marine and truck/towing cams and shoot for about 5000-5500 RPM max. BBC don't have the best oiling so I wouldn't want to cam for more than 5500 and you don't want to have to worry about reversion at idle.

I recommend all these things because it's cheap and easy to do it now while everything is apart. Be as thorough as time and finances allow.

[TitanTn]

You guys make a compelling case. I was hoping to not make this THAT big of a project, but I'd rather do it right anyway. Anybody want to come hang out in Chattanooga for a few days this winter? Free room and board!

[92SupraComp]

stand 2 feet behind twin 330 hp 454's with dual 4" stainless on each motor with the exhaust 2 ft above the water....

then stand behind twin 700HP 502's with Whipple supercharges, and again, dual 4" stainless on each motor...

oh the chest pounding power!!

arh arh arh (tim taylor lol)


then , when they take off....

[Jetlink]

Have you heard this motor? Trust me, it sounds nice! I was in the water and had my ears about two feet away when Titan cranked it up and it makes a nice deep sound. Makes mine sound like a sewing machine.

Haha, sewing machine...yeah right...you sell yourself and your boat short.

[TitanTn]

Did we get off subject? This boat only has one engine.
I've spent some time in the past driving a twin Baja 75 mph down the lake and felt more like Mario Andretti than Tim Taylor.

More like a Honda motor then?

You spend too much time behind the helm! Yours sounds more throaty than you realize. Every time you take off I have to remind myself that it's a small block. It's throaty w/o being obnoxious. Mine is on the border of being obnoxious, and I certainly don't want to do anything that increases that noise volume.