| Title: | Powerboats |
| Notice: | Introductions 2 /Classifieds 3 / '97 Ski Season 1267 |
| Moderator: | KWLITY::SUTER |
| Created: | Thu May 12 1988 |
| Last Modified: | Wed Jun 04 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 1275 |
| Total number of notes: | 18109 |
Didn't see a note for Inboard Engine Rebuilding... <usual disclaimers> A slight but noticeable decrease in performance, minor oil consumption, an exhaust manifold gasket leak and 1200 hours has all contributed to my thoughts of a total engine rebuild for the Nautique this winter. (Did he say "winter"?) Other arguments are that I *really* like my boat with it's tan hull base color (which is no longer available w/o special Order), overall great condition and that a new replacement is in the 26-33k range. The engine is a 1987 Holley carb'd 351 PCM, Mallory ignition using points and condensor. The question is, how far do I take this? While I'd like the "extra" power of a blower, open headers and nitrous I don't think I'd like the headaches. Not to mention, the blower would interfere with the tow rope! :-) I'm thinking a mild performance upgrade would be more reasonable, not only on the wallet, but also for reliability. But, I'm unsure how far to take this.... Obvious stuff.... A little custom head work. Hone the cylinders. New rings, Oversized maybe? Timing chain and gears. Turn the crank. New seals, gaskets, bearings..... New cam and lifters. Not so obvious stuff.... New pistons? New oil pump? Ignition system upgrade? To what? Carb rebuild, even if it's running fine now? Maybe an upgrade here as well? Intake? Any guesses on cost? I SWAG 1-1.5k for the obvious stuff doing the work myself. Not so obvious stuff???? depends... could reach 3k easy, huh? Rick
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1262.1 | Visit your local speed shop | SUBSYS::CHESTER | Wed Jun 19 1996 13:40 | 16 | |
Take a look at the local "speed" shop for parts. There are many intake
and cam kits available. Most of the vendors have three levels of
preformance increase. From mild to extreem. The mild work ok with the
std bottem end (crank, rods etc) the others need new rods and crank
to handle the higher operating RPM. The other result will be a narrower
torque peak. The other expectation of these "speed" kits is the use of
93 octane gas. As well as fresh water cooling for the aluminum intake.
Mallory has a nice electronic ingition module to replace the points in
thier distributers. I have been using two for the past three years.
Personal opion is to get a new cam and intake that has torque and hp
peaks within the engine's current ratings. Then change the ingition
Ken
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| 1262.2 | Why not a Scorpion?? | GAAS::HYER | Wed Jun 19 1996 13:57 | 10 | |
Rick, Sounds like your list is complete. If I were gonna keep the same block, I'd opt for an aftermarket EFI and skip the nitrous. Won't get the same performance boost, but won't get the headaches either. On the other hand, the performance for the new Scorpion engine is real impressive. What are the chances the mounts and trany can be made to match? And only a *TAD* more than your $3K estimate I bet. dave | |||||
| 1262.3 | A couple thoughts | FOUNDR::DODIER | Single Income, Clan'o Kids | Wed Jun 19 1996 14:10 | 18 |
I just took a look at an old ('93 ?) JC Whitney catalog and saw
a Hi-performance rebuild kit. It included cam, lifters, main and rod
bearings, dbl-roller timing chain/gears, high volume oil pump, and gasket
set for $216. Unfortunately, it was only for older small block Chevy's.
Perhaps a newer catalog (or a regular speed shop catalog) will have
something similar for the 351. Then you could go with either a new ring
set, or piston and ring set. Figure about $30-$40 or so for the ring set
and about $15-$20 each for pistons. The rebuild set also didn't include
valves and valve springs which you may also want to consider.
A high output ignition coil and wire set is pretty cheap in the
grand scheme of things, and may be another thought. Other than that,
a decent machine shop will be able to also give you some ideas that
might not be too expensive (i.e. planing the heads).
Ray
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| 1262.4 | have it balanced | UNIFIX::BERENS | Alan Berens | Wed Jun 19 1996 16:14 | 12 |
re .0: Since you'll be completely disassembling the engine, I'd suggest having all of the critical parts tested for cracks (magnafluxed or whatever) and having the engine balanced. A carefully balanced engine runs much more smoothly than the usual thrown-together factory engine. Years ago, I rebuilt a four cylinder 2 liter Rover engine and had it balanced. It ran so smoothly that I almost had to look at the tachometer at idle to be sure it was running. The cost of balancing wasn't all that much, as I recall. Alan | |||||