3.7LX

[Trevor]

Hey just purchased a 30 Bayliner with a pair of 3.7lx engines the owner told me that one cyl in the stb. eng has no compression. iput some oil in it and the compression came up so the rings are gone the guy said he ran the engine like this for about 2 years the perorms well you would never know but the one engine is hard starting and misses at idel so i have decided to eather repower or replace this engine I can buy a reman from mercury and rebuild the motor that is in the boat as a spare the outher motor has 1600 hrs on it now. what should I do are these motors worth this are parts hard to find would V-6 be a better choice there is a nother boat in my marina with twin 350 in it goes like stink out of the hole but I cruise at the same speed as he does.<br />also have 21 larson lazer with an omc 5.7 cobra in it keeps burning points?

 

[Walt T]

Re: 3.7LX

A 30 footer with 3.7s is underpowered in my opinion. I'd go with twin 454's. 5.7's probably be okay though.<br />Diesels are really the best choice for a boat this size.

 

[Trent]

Re: 3.7LX

Convert your OMC to electronic and dont worry about points again. I agree with Walt...3.7 is a little underpowered. 5.7 Min!

 

[Capt Ken]

Re: 3.7LX

I would change the engines but in order to not have to change gearing in the drives, I would go with the 4.3 Vortec. If you went with the EFI units, you would get 220 hp out of the engines. That's only 30 hp less than the 5.7 but less weight. Problem is, those 4.3's would cost you about five grand each. The 190 hp carbed 4.3 would be a grand less.

 

[geriksen]

Re: 3.7LX

EFI 4.3's would be perfect for this boat. The problem you are going to have with this kind of conversion is that you are going to have to add four stringers to the hull for the motor mounts to bolt to, unless the boat already has them. You would be surprised how well 4.3's will run a 30foot boat. Power to weight is awsome.

 

[Trevor]

Re: 3.7LX

thanks guys the 3.7lx motors push the boat to a cruising speed of 22 knots max of 28kts and between the two motors I have averaged about 14 gallons per hour.<br />The boat already has the stringers in it to mount a new set of motors. will the ratios in the legs work with the 4.3 EFI motors and do I have to change any thing in the wiring harness or can I run them off the same system? <br />any body wont to buy a set of 3.7lxs?

 

[Capt Ken]

Re: 3.7LX

That's why I suggested the 4.3 engines. The gear ratio is the same as the 3.7's. Anything bigger and the gearing would need to be changed. With the mercruiser harness already there, all you would need to do is plug it in. Now you would need to go to the rear of the tach's and change them from 4 cyl to 6 cyl.

 

[MrBill]

Re: 3.7LX

I hesitate to comment on the power requirements of your boat, but I have seen alot of in-line 3.7L 4 cylinder engines and components on eBay during the last three months for very reasonable prices, use the search "(mercruiser) 3.7", for engines/components or just "(mercruiser)". Also check 'completed items', you can contact the seller of items that did not sell and/or the buyer of items to see if he/she would re-sell to you. I've had good success for many parts and assemblies on eBay.

 

[Trevor]

Re: 3.7LX

Thanks guys I have decided to stay with the 3.7's only because I can rebuild the outher one and still end up with a spare engine. <br />Thanks again for you input

 

[chiefmike58]

Re: 3.7LX

Trevor, since you are going to stay with the 3.7s I will give you a little info on them. The engine was built by Mercruiser with a Ford 460 head on it. The block is aluminum with steel sleeves. With a 2bbl carb they have 170hp, with a 4bbl they have 190. Remanufactored versions are available much less expensive than Mercruiser. Two main problems with these engines are no.1, water circulator mounted on front nose of camshaft with two seals separating water from oil sometimes wearing groove in camshaft creating leak. There is a sleeve kit available to repair this without removing cam that works great. No.2 is that alternator is mounted on front of crankshaft with regulator on side of block with copper pipe running raw water through it for cooling. If copper pipe breaks down and leaks this can cause electrical shorting in regulator. Fix for this is aftermarket car type alternator with regulator within available all the time on e-bay for around $375. I have a 25ft Grady with twin 3.7s, also known as 470s, and a spare in the garage that I am rebuilding this winter. One very important thing is to run only non-detergent 30weight or 40weight oil. Do not use detergent oils such as 10w30, 10w40, as these will not properly hold up in these engines and will definitly cause problems. Last but not least is that if you have the freshwater cooled version you should have 4in. heat exchangers other than the 3in versions. They do a much better job. If I can give you any other info on these motors feel free to send me an e-mail. Mike cmartoe@msn.com

 

[chiefmike58]

Re: 3.7LX

Trevor, I don't know if you are interested or not, but a guy I know is repowering his boat with twin diesels and removing two complete Mercruiser 470s with outdrives, bellhousings, controls, etc. which he states as being in perfect order that he wants to sell all for $4ooo. If you are interested I am listing his e-mail address below.<br />Hope this helps. Mike<br /><br />alexvk@optonline.net

 

[Trent]

Re: 3.7LX

Chiefmike...Id like to know why you say not to run detergent oils? Are you saying to use mineral oils or low ash or ashless oils? Straight VISCOSITY oils I understand. <br /><br />Its funny after all these years most people think that the "W" in let's say 10W40 motor oil means "Weight" its never meant that!! The "W" means it's approved for " WINTER USE " NOT WEIGHT!! People confuse it with weight.... Its VISCOSITY not WEIGHT..

 

[Trevor]

Re: 3.7LX

detergent oil will foam if beat hard enough I have a 69 mustang fast back built a 302 for it revs to 9 grand dont like detergent oil

 

[Trent]

Re: 3.7LX

Make sure you compair apples to apples and oranges to oranges.

 

[gboulware]

Re: 3.7LX

Hello, I have just run accross the website and have registered today. I bought a Wellcraft 186 eclipse 1989 five years ago and did not know jack about what to look for. I had to tear out the floor, runners, stringers, foam and start all over. Then new upostrery, carpet and $6000.00 later a good boat and Ilove it. I also had to have a coolent leak fixed at the camshaft. Now I need a new engine or rebuild this one. When I rebuilt the boat it is now a little heavier and I would like to go from 165 hp to 190 hp. I saw Trevors and Chiefmike58s post about a pair of 3.7lxs. I am tired of working on this boat for awhile and just want to have some fun on the water for for a season. I am looking for a good deal on an engine that I can just drop in without changing the mounting points. (not much room under the hood) Anyone know of any good deals on a 3.7 460 190hp? Also will these engines be OK with my alpha one? A 180 might be OK as will and an altenator kit on the engine would be super. <br />Thanks