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Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed Apr 29, 2015 4:34 pm
by RJC5778
update, ordered a flexplate from diamond back which ended up being the wrong one, waited 2.5 weeks for it btw, anyways ended up being the wrong one as I have a gen 5 1.914:1 reduction, never heard of that, but after talking to Robert at century drive, ordered the correct plate and new Blackhawk belt, so hopefully I will get it in by Saturday. has anyone ever heard of a 1.9:1? the reduction was bought is 97 by diamondback but has 2:1 stamped on the case? bottom gear has 58 teeth and top has 111 teeth.......very odd but Robert assured me ill be fine with what I ordered so here we go again with another flexplate hahaha

Re: Robicheaux hull rebuild, 496 stroker

Posted: Mon May 04, 2015 11:10 am
by RJC5778
well I put in a good 30 hours of work this weekend and got the boat running, it is not 100% just yet, still need a few parts but its very close to being finished, it sounds great and runs as expected, played with the props a bit sunday and im a do a final adj when its all complete, im at 1 1/2" mark as of now spinning 5100 on the trailer, im a prop it back to 4900 on the trailer and have a ground max of 5000, with the peak torque at 4700 I think it will push great, overall im please with the way it turning out, would love to put a 2.3:1 in the future to really make those blades swing but gonna run it like this for awhile and see how it handles and runs, being that its an older gen 5 reduc, so gonna see if I cant find a used 2.3 for a good deal in the future. but it breaks free at 38-3900 as of now without messing with the motor pitch at all like I said once its all complete im a mess with that and spend some time dialing it in, here are a few pics from the weekend

Re: Robicheaux hull rebuild, 496 stroker

Posted: Mon May 04, 2015 11:32 am
by PAINKILLER
Congrats on getting done

Re: Robicheaux hull rebuild, 496 stroker

Posted: Mon May 04, 2015 1:28 pm
by RJC5778
its not 100% done, no seats or throttle hook up yet and I still need to do some wiring and fit and finish work, ma main goal was to get it wired up to run to hear the engine for the first time, which I accomplished and am satisfied with so far, I still think I am not utilizing my blades as much as I should with the gear reduction the way it is, shouldn't be long now till it back on the water

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue May 12, 2015 9:05 am
by RJC5778
wells guys and gals, that's about a wrap on this build, I got it 99% done, just need to mount the front hatch under the captains seat and 1 bolt for the throttle return spring and that's a wrap, im gonna add the courtesy lights at a later date as its almost snapper season down here and I need to get the offshore boat ready to go for some spearfishing, well anyways I am really stoked on how it turned out and should do some testing tomorrow afternoon after work, ill post some numbers on what I find out on the test run for you guys and more pics and a video, if I can figure out how to upload a vid

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue May 12, 2015 1:54 pm
by 90chevy396
Great looking boat man. glad to see you finally get to test drive it. been a long time coming

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue May 12, 2015 2:15 pm
by PAINKILLER
Looking good can't wait to see it run in the video

Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed May 13, 2015 8:33 am
by RJC5778
dropped her off the trailer yesterday afternoon and took it for a spin.......ran great, made 3 runs in the pasture and slides nice, motor never overheated and no shakes or shimmy's, rudders respond well and turns well, I didn't get a video I apologize, more testing in the near future, then put it back on the trailer and washed it all top to bottom inside and out here are some pics and before and after ref pics

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue Jun 02, 2015 9:33 am
by RJC5778
update: I got some time to do some testing and im a post my findings, pitched the boat to turn 4900 on the trailer and im spinning the 3 blade ngr at pitch 2 with the 1.9:1 gear, buttoned up a few items and dropped her off the trailer and man what a difference the motor made, mid day I can break free on dry green grass at 3500-3700 rpm, boat flat out has some power, cant wait for the 2.3:1 in the near future and really put some pitch in these blades, got the motor pitched down an 1/8th of a bubble down in the rear and got the boat to "rock" forward upon throttle up, I cruise in deep water a 3000 rpm doing about the same speed as before (not sure of the speed just going off memory and feel) it still hops at fast cruise, not a big deal but may need to put a trim tab in the future, it "feels" lighter with the aluminum heads and obviously more power helps, very very happy with the boat and it will just get better with the 2.3:1, also got the deck and cat walks herculined for grip and also the floor here are some pics

Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed Jun 03, 2015 4:33 pm
by flying fish
Good job man! Enjoyed watching the re-build.

Question
Do you think you would have better throttle responce due to better fuel atomization below 5000 rpm using the correct dual plane intake manifold??

I say guaranteed. JMO- :)

Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed Jun 03, 2015 6:59 pm
by jopete
looks great!!!!

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 8:35 am
by RJC5778
flying fish wrote:Good job man! Enjoyed watching the re-build.

Question
Do you think you would have better throttle responce due to better fuel atomization below 5000 rpm using the correct dual plane intake manifold??

I say guaranteed. JMO- :)
fish: I actually have a high rise single plane intake, its a pro filler sniper jr intake with an hvh billet adapter 4500 to 4150 carb bore, the intake has a 2 inch spacer built in and the hvh adapter is another inch, I noticed after running that the top of the intake and spacer will have condensation developed on it, its very responsive with loads of usable power, if I change the cam in my motor I can easily have an 700-800 hp motor but it be above wher I could use it so its no point, im very happy with this engine, its strong and overbuilt

also, here piggy piggy

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 10:17 am
by flying fish
Are you still running the 4" stroke in your piece? 470ish CID?

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 2:44 pm
by RJC5778
flying fish wrote:Are you still running the 4" stroke in your piece? 470ish CID?
nope bored .070 over stock 454 bore and stroked, its a 498 stroker motor producing 603 lbft torque at 4700 and 593 hp at 5400

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 3:31 pm
by flying fish
Was having a time figuring out how you was making that kind of torque. Makes since now.

Last question
Do you think your A/F ratio is a bit on the lean side for extended hard running and keeping EGT's acceptable.

Or, have you richened her up a bit compared to what you posted?

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 3:50 pm
by RJC5778
flying fish wrote:Was having a time figuring out how you was making that kind of torque. Makes since now.

Last question
Do you think your A/F ratio is a bit on the lean side for extended hard running and keeping EGT's acceptable.

Or, have you richened her up a bit compared to what you posted?
I was told by the engine builder that just adding the air cleaner with inherently richen the engine up a bit, and also to drop the timing a bit, im 36 deg all in right now on 93 octane, I plane on retarding it a bit for summer running to around 34 deg, he said in the winter to fatten it up 2 sizes as well on the jets

Re: Robicheaux hull rebuild, 496 stroker

Posted: Fri Jun 05, 2015 3:59 pm
by flying fish
Complete BAMF piece.

Again, you have skills. Good lookin ride.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue Mar 28, 2017 4:16 pm
by RJC5778
well I know this is an old thread but I put about 70 hours on the engine and hull and I cant be more pleased. I changed up a few things but here she is all complete and broke in.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue Mar 28, 2017 5:33 pm
by SWAMPHUNTER45
Glad to hear it is going well. At 70 hours your probably fully broken in now and enjoying max power for your build. It is nice to hear when things turn out well and the boater is happy with the project.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed Mar 29, 2017 9:25 am
by br,lc,LA
Join us over on Facebook if you have it... Southeast Texas Airboats. We arrange rides all over the state of TX and make trips to Florida, etc. Always welcome more into the group for big rides.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Thu Oct 11, 2018 5:37 pm
by RJC5778
old thread but update, the old 498 lasted 3 years and about 150 hours before the old tired block cracked. of course it cracked about 200 yards from he nearest canal. let her cool down then ran her back to camp. sent a head bolt out the block (pretty eventful to say the least) long story short, bought a new 540 dart block with all the same internals (minus piston) those are new to fit 540 block, will update once i have it back together in the next month or so.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Thu Oct 11, 2018 6:29 pm
by br,lc,LA
Facebook Southeast TX Airboats and come join us for a ride... The Louisiana guys dont ride enough!

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue Oct 16, 2018 12:34 pm
by RJC5778
block cracked near a head bolt..

now she is a 540. all same internals as previous motor minus new pistons and rings. brodix head fixed (cheaper than i thought - washed out aluminum between cylinders) prolly in the high 600 low 700 hp range on a dart sportsman true 540 virgin block. hopefully she lasts a good while.

Re: Robicheaux hull rebuild, 496 stroker

Posted: Tue Oct 16, 2018 3:46 pm
by jopete
did you ever switch to a 2.3 box? if so, do u like it?

Re: Robicheaux hull rebuild, 496 stroker

Posted: Wed Oct 17, 2018 12:03 pm
by RJC5778
Jopete,

no sir we did not switch, im running the same 2:1 and have been please with the set up, i can load 4 guys and a 14' wood deer stand in the boat and run dry ground with the 498. now that i will be running a 540 i think i can spin the NGR blades harder. i can point the point practically anywhere i want to go and not worry. ill be picking up the new engine tomorrow an plan on having it back in the boat in a few weeks.