7.4L top end refresh

[TitanTn]

I've got what sounds like a ticking lifter or two. If I get the rpm over 2900 for more than 5 minutes, when I come off plane you can hear the ticking at idle. After a couple minutes of idling the ticking will go away.

So, this winter I'm going to do a top end refresh. Anyone want to offer some things to make sure I do, or just some tips in general? I plan on replacing all the lifters, and I'm pretty sure that means I should replace the rods as well. I'll take the head to a machine shop for rebuilding.

I'm not really interested in building more power, so no need to suggest tips for building 500 hp. The stock 330 is fine with me. I'm not drag racing anyone.

[Blackntan90]

If it is in the budget I would just rebuild completely. Not too much more to tear down, other than removing the engine from the boat. That way you can have the machine shop clean all the oil passages of gunk, and other checks for cracks etc. Then you would know the engine is done. it would be ready for many more years of use, hell with what you have already done to the rest of the boat it would be all new where it counts! So you don't want to replace the intake with an aluminum aftermarket for better all-around performance? I have been toying with the idea lately, It would be a cheap and easy way to gain power, less weight etc.

[haugy]

Yeah I'm with Rich. If you've got it that far apart it's not a bad idea to do a whole thing. But that's just me, Captain Overkill.

I need to research because I can't remember which heads ours have, but I think you can have the ports machined to allow better airflow. I believe our ports are rectangular and the newer heads are more rounded out and smooth. Smooth boring the heads would be something I would do. It doesn't up horsepower, but it does allow for better airflow and that can help with fuel consumption and response. I'd definitely swap what I could to aluminum for weight, temperature, better designs, etc.

I can't remember but research just changing the rods and complications. I always do a full rebuild on my engines when I pull them, but if I remember right there can be possible complications from putting in new rods (if they aren't bent) and possible grooves or channels in the camshaft.

Be prepared for new valves (unless that's part of the freshen up, didn't have details). Are they dipping it? Or just pulling out old stuff and putting in new? What is their plan for "freshening up"?

Don't forget to put flame stickers on the valve covers, that adds 15 horsepower right there.

[Jetlink]

But that's just me, Captain Overkill.

Captain Overkill looks like an amateur compared to you dude.

I echo the above responses as well, why not go the extra mile and take care of the whole engine once and then have the piece of mind going forward? I am already planning my engine overhaul when the top cap comes off and it will be a full rebuild both boat and engine at that time for this guy.

[wotan2525]

Why pull the engine if you don't have to?

I'd pull the heads, have the valves serviced and inspect the pistons/bores. I wouldn't replace my lifters without replacing the cam at the same time. A new timing set would also make sense to me.

How about intake? This would be a great time to switch over to an Edelbrock Performer II (which you may be able to find cheap on craigslist.)

[92SupraComp]

at least throw a decent cam in, give it a nicer sound.

i like the sound of cammed motors :P

[Kma4444]

If you have tapping after running it as you mention, I would suggest you have a problem with the lifters or oil pressure/oil supply. If your oil pressure drops to the point where it cannot keep the lifters extended enough to take out the lash then you will get the tapping noise you mention. The lifters can cause this by having too much wear but it's not common and would more likely show up at base idle where oil pressure should be lowest in an engine with no other problems. If you have a restriction in your oil pump pickup then you will loose pressure as rpm increases and can cause exactly what you mention. The restriction is most usually sludge of some kind that restricts flow through the screen on the pickup tube.

Easy enough to diagnose and repair, once the engine is out. Sounds to me like the smart money is on pulling it and giving everything a good look.

[Moor]

Don't forget to put flame stickers on the valve covers, that adds 15 horsepower right there.

Make sure they are chrome valve covers with a matching chrome air cleaner, they shoulbe be good for about 5 horses at the prop. add the flame stickers and you will be the fasted ski boat on the water lol

seriously tho, i would strongly consider a full rebuild if its finacially feasable. like people said, its not that much more expense or work, and the heart of your boat will be brand new. who knows how much metal from your worn out, ticking lifters has found its way into the connecting rod and main bearings? as also noted, the tick may be due to poor oil pressure or gummed up oil passages inside the motor... if thats the case, who knows how much damage has been done to all of the wearable surfaces inside your engine? if the oil pressue is weak due to a bad pump or clogged up oil passages, there is no doubt that premature engine wear has taken place. the question is: how much wear? if it were me, since its a boat, and not exactly like you can call a tow truck like if your car broke, id replace the piston rings, rod bearing, main bearings and oil pump at the very least, just for some peace of mind.

[Moor]

another thing to think about.... what kind of engine oil are you running? you should be runnin oil with a high content of the zppd additive, otherwise, premature cam and lifter wear can (and usually will) occure. do a google search on zppd and camshaft wear

[92SupraComp]

Mobil 1 specs

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

I use 10w-30, it has 900 PPM of zinc.

Switched my CC over in 2010 when I got it and my comp will get changed this year.

[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.