342 engine rebuild
cduffy
Member Posts: 11 ✭
Hey all, looking for advice, must dos, must not dos. Pulling both engines and gen to rebuild the engine and clean up gen. Any parts that should be swapped while the engines are out? Have twin 350 Horizons.
Comments
Id price rebuild and price new GM blocks. With labor rates many times its close to the same price. The race shop next to me rarely builds motors for circle track guys because the crate motors are so competitively priced now. These guys date back to when the Earnhart family raced in Greenville Pickens Speedway, they used to build dozens of motors every week during race season.
DO follow proper break in procedures as directed by builder or manufacturer.
If you want power you can add parts at this time. Every 40hp is about 1mph because you cant be late to happy hour 😄
Probably about as much room as the 270 with a big v8. Sadly those motor have been obs for years.
I couldn't imagine draining blocks on two v8s in a 270
Now give me two inline 4 diesels!
other than electronics i can't think of any items that would make a diffence in a truck or marine engine. The programming is just a little different, im sure most has to do with lack of an o2 sensor(have a buddy that tunes go fast LS engines that go in camaros/boats/vetts/etc, he's anti diesel and trying to get me to go 6.0 LS). This is obviously in a closed loop system where as a raw water needs special freeze plugs, stainless headgasket as well as water pump and cooler thermostat. We can debate cams but to me a vortec rv/truck cam is close enough to a marine cam to call it good although there are better performing cams out there that wont suck water than either of those. Come to think of it dont most of the newer motors use bronze(maybe brass) freeze plugs?
You can tell I've been out of the newer vehicle market for a while. Before my excursion my daily driver was 1967 vintage. Life was good. I had swapped a v8 in that for years until the diesel but got to me.
I think it was the old Thomson boats that boasted the 327 corvette engines, their coded blocks were directly from the vette assembly line and destined for closed cooling.
Usually bottom ends are beefed up for higher compression/forced function/higher horse power builds as well as higher rpms. They do see more load than automotive engines but they dont see 5000 rpms clutch drops like you'd see at the track 😄
My comment about cams is regarding the fact that due to a better design you can get away with a little more aggressive cam on new roller rocker engines than you could on the flat tappet cam.
My question was more of what components to swap out while the engine is easy to get to everything. I am not really looking for HP, we are on a lake and slow cruise most of the time and when we do want to get up and run on plane, we havent had any problems with current power. Just looking at the convenience while not climbing in the engine room.
If I could get a re-build done for $1,500 I'd be all over it. Since starboard was a new long block I plan to do the same for port.
Just wish I could reset the hours on the computers.
2002 FV 342 on Lake St. Clair - Past Commodore SHC - Vessel Examiner USCGAUX
Check all your wiring, especially around the exhausts pipe for any chaffing or melted casings. I had a few worrisome spots.
BTW - if no one has mentioned it yet - with the engine(s) out I'd look carefully at bilge pumps (great time to up-grade) vent hoses - easy time to replace, through hulls - also a great time to re-tighten or even re-seal any through hulls.
Even if only one engine is out most of the hardware is waaaay easier to get at!
@cduffy .....*****I may stand corrected: There is a lengthy thread regarding Hardin Pumps on this forum (presently running) I was not aware that newer versions may require a bearing replacement at +/- 200 hours. This is news to me and you may wish to investigate that.
Regards,
Ian
The Third “B”
Secretary, Ravena Coeymans Yacht Club
https://www.rcyachtclub.com/