BBC 540 Lingenfelter Dart heads.
 

Help. Need to replace head gaskets on BBC 540 with Dart heads. What additional information is needed in order to get the part number of the gaskets? Also, do the head bolts need to be replaced? Any additional info would be appreciated and the part number for Fel-Pro head gaskets. I have sent emails to Lingenfelter asking for help and also to Teague asking what additional info is needed. For some reason they haven't respond!

I could be wrong, but unless Teague Marine built the engines I highly doubt you will get a response from them. I would think any competent engine builder in your local area would be able to figure out what head gaskets your engine has/needs.

Nice looking boat---how fast?

There are three issues with head gaskets-

1. What generation is the block? Mk IV, or Gen V/VI?

2. You need marine gaskets- FelPro, Cometic or copper. In the correct bore size- 540's are 4.5".

3. Deck height/squish- you need to measure your deck height to determine gasket thickness. Too thick a gasket will drop compression but worse, will kill the squish. That's where the flat of the piston approaches the flat portion of the head. Too much space and you don't get good intake charge movement= loss of power. On the other hand, too tight will mean contact between the piston and the head- or a valve. There's no reason you can't just measure what was in there- but you may lose performance.

You may want to find a reputable high-performance shop to do this for you. There should be dozens of guys just to the south of you.

One other thought- I'm assuming you're replacing head gaskets because they were leaking. The heads probably need to be surfaced- not milled. No reason to replace head bolts.

Thanks Chris. I PM'd the original owner of the boat. Am trying to get more details. Right now only getting water in #8 and no water in oil but want to replace before it gets any worse!

Chris. The block is is a Gen V 4-bolt. The heads are oval port. Lingenfelter built it as a blower engine. M3 ProCharger. Hopefully all this helps.

It's a start. Now you have to make a choice. It ran OK with the gasket that was in it so we know the squish is outside of the physical damage area. If you want to stay here, measure the gasket with a micrometer or a caliper. If you don't have one, Harbor Freight will sell you one for about $20. Worth having for alot of other things any way. Option 2 is seeing where you're at on squish. For that you'll need either a depth micrometer with a minimum of a 5" shoe or a parallel and the mic you just bought. What you're looking for is the difference between the top of the deck and the top of the piston at TDC. If you want to go this way, let us know and we can get into the details.

Since the head leaked, send them to a good high-performance machine shop and have them surfaced. Take as little as possible and preferrably have the chambers cc'ed. Ask them to tell you exactly how much they took off and make sure it's the same amount from both sides.

Ok. Chris. I got a good performance guy that I'll take the heads to.
Thanks alot for the info. We'll Git er' done!!!!!

Good to hear. I'd suggest you stick with either the FelPro marine or the Cometic Marine gasket. Make sure they're marine.

It's a good time to have your exhaust pressure tested and re-gasketed if applicable. That's probably the single biggest marine motor killer.

I have Stainless Imco. Did that when I first discovered water in #8. Changed intake gasket also.

you need to look at the heads and see which style gen IV or V, VI heads they used and then you can go to felpro's website and their chart will tell you the part # you need, Rob

Chris. You seem to be one of the most knowledgeable people on engines on the forum. Boat is in being worked on. The cast iron Dart heads have grooves and the block has o-rings. The head gasket has copper rings that seat on the grooves and o-rings. My mechanic said I'd probably be better off and cheaper getting new head than welding the corrosion pockets, milling the head and then re-grooving. My leak in #8 was caused by one of these corrosion pockets. I guess this was a Lingenfelter idea to o-ring and groove. Can I have your expert opinion on my situation?

Sorry to hear that you have o-rings. Your mechanic may be right. Dart Iron Eagles are fairly cheap for a performance head, about a thousand a pair bare. I don't know why people still use o-rings. Fel-Pro is good for about 10 lbs of boost and Cometic is good for as much as the heads or the head studs can handle. If it were mine, I'd tear them down and remachine the heads and decks to get rid of them, then use a combination of proper thickness Cometic gasket and piston machining or new pistons to eliminate the o-rings. If you continue to use o-rings they will probably give you trouble again. Sorry.

Thanks for the compliment. Most of what I know is courtesy of others- much from the other knowledgeable people on this board.

I have a local welder thay performs miracles and doesn't charge much. For me, it's a no-brainer. If you can find a local guy who can do this for you, it shouldn't cost much. If you don't mind boxing & shipping to Ohio, I can put you on to my guy but that might get expensive.

Since we're this far into the engine, decided to pull the block and mill it removing the o-rings. I think i'll be better off in the long run. True?

I think it's best but I do most of my own work. I hate to think what it's costing.

You better find out what your current deck height is. You can get a thicker Cometic gasket. What block is it? Some are generous on deck, others are right at spec.

My engine guy is going to do that. Thanks Chris! He's going to do his magic mojo **** on it for more horses.