Search found 109 matches

by RJC5778
Mon Mar 25, 2019 5:40 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

well, she is all back together and i have to say she is quite powerful. 1st thing i noticed i that the 540 is smother than the 496. 2nd alot more torque (spinning 3 blade 80" NGR at pitch mark 2 at 4900 on the trailer static. overall im pleased with the new motor, time will tell and after a few...
by RJC5778
Wed Jan 02, 2019 10:51 am
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

running gear is back together and got a chance to run it on the trailer a bit to see where it stood. set the prop and around pitch mark 2 and got 4500 rpms out of the 2:1. for comparison, i could only spin the NGR's at pitch mark 1 at 5400 rpm with the 498. this motor seems to be smoother at idle ov...
by RJC5778
Tue Dec 18, 2018 4:49 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

yes, summer running is always hard to run. well the running gear is all back together and now im just waiting on a few upgraded parts to finish her up and run her. im interested to see what kind of pitch i can spin now with the bigger motor. all things being equal minus the extra cubic inches should...
by RJC5778
Wed Oct 17, 2018 12:03 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

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 anywhe...
by RJC5778
Tue Oct 16, 2018 12:34 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

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 las...
by RJC5778
Thu Oct 11, 2018 5:37 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

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, bough...
by RJC5778
Wed Jul 18, 2018 12:55 pm
Forum: Automotive Power Only
Topic: 496 vs 540 BBC
Replies: 12
Views: 1981

Re: 496 vs 540 BBC

Rbode, i can shed some light on this as i have both engines, first one is a 498 airboat built engine, i have specs and dyno test to prove all this on my build thread, its on here somewhere "robicheaux hull rebuild". boat is a 14x7.5 robicheaux work boat hull, built a new 498 stroker with a...
by RJC5778
Wed Feb 21, 2018 10:22 am
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 10938

Re: 502 power VS torque

With this size boat, I like to think that he would need a big inch motor with a high gear ratio and as long as a blade as possible DIA wise. this seems to be more of a work application rather than speed. he needs torque and more torque, essentially a large area under the curve, more thrust is to be ...
by RJC5778
Tue Mar 28, 2017 4:16 pm
Forum: Automotive Power Only
Topic: Robicheaux hull rebuild, 496 stroker
Replies: 78
Views: 12500

Re: Robicheaux hull rebuild, 496 stroker

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.
by RJC5778
Fri Aug 26, 2016 2:38 pm
Forum: Automotive Power Only
Topic: 572 bbc reliability
Replies: 31
Views: 7616

Re: 572 bbc reliability

inconel exhaust valves would be a great upgrade for piece of mind, as with anything mechanical if you keep care of it and treat it right and learn what it likes it will give you many hours of operation, start dogging it and running cheap gas/oil, it wont last as long and you know where that leads, m...
by RJC5778
Mon Aug 22, 2016 9:42 am
Forum: Automotive Power Only
Topic: 572 bbc reliability
Replies: 31
Views: 7616

Re: 572 bbc reliability

personally, id shy away from a crate motor, if you have a bbc already, i would send in to someone who has built airboat application engines before, these engines live in the higher rpm band 90% of their lives, maybe not your application of a bowfishing rig as i assume you idle alot, so its a trade o...
by RJC5778
Thu Aug 04, 2016 3:50 pm
Forum: Automotive Power Only
Topic: Which big block - 454 or 496?
Replies: 21
Views: 3976

Re: Which big block - 454 or 496?

we both treat it "normally" with the occasional flogging if needed, thanks for the advice waterthunder. i think i have some great parts in my engine, i dont hesitate to flog it when needed but its mostly cruises at around 3500-4000 most of its life
by RJC5778
Thu Aug 04, 2016 10:44 am
Forum: Automotive Power Only
Topic: Which big block - 454 or 496?
Replies: 21
Views: 3976

Re: Which big block - 454 or 496?

i have had both engines run on the same boat, i blew my 454 up (dropped and lifter) complete tear down, blue print and rebuilt to 498 stroker, only thing he used was the block and main caps, built for airboat/marine application, beat the dog out of it and runs great with good usable power, brodix he...
by RJC5778
Wed Feb 03, 2016 3:35 pm
Forum: High Performance Talk
Topic: NEW BBC HP?
Replies: 4
Views: 2153

Re: NEW BBC HP?

can you post the displacement on this motor? bore, stroke, cam specs, carb, all that jazz, must be a torque monster to spin a prop like that or the cage gap is small causing the prop to cavitate, I have a dyno tested 593hp airboat bbc 498 ci with a 2:1 belt drive spinning a 3 blade ngr 80" dia ...
by RJC5778
Tue Jan 26, 2016 11:47 am
Forum: Automotive Power Only
Topic: BBC valve cover baffles
Replies: 47
Views: 5507

Re: BBC valve cover baffles

I 100% agree, I have over 100 psi oil pressure at the upper rpm band and I know with the prop creating a large vacuum and right conditions it will suck the oil out the breather w/o baffles, im pretty confident in this system as it has 2 baffles perpendicular to each other with will prevent the oil s...
by RJC5778
Tue Jan 26, 2016 8:13 am
Forum: Automotive Power Only
Topic: BBC valve cover baffles
Replies: 47
Views: 5507

Re: BBC valve cover baffles

finally had time to put the valve covers back on, I sure hope they work
by RJC5778
Wed Jan 20, 2016 9:05 am
Forum: Automotive Power Only
Topic: BBC valve cover baffles
Replies: 47
Views: 5507

Re: BBC valve cover baffles

no just a 9 quart oil pan for marine use, I got the breathers on and the oil fill installed, the powder coat came out good, iva attached a picture, I will test this next time I run it hard and see how she does
by RJC5778
Tue Jan 19, 2016 1:44 pm
Forum: Automotive Power Only
Topic: BBC valve cover baffles
Replies: 47
Views: 5507

Re: BBC valve cover baffles

its a newly rebuilt dyno tested motor, I bought a moroso 68800 kit that has 2 baffles per side perpendicular to one another and an oil fill plug, the breathers are shielded, if this doesn't work I will bring it to the engine builder for a leak down test, its not a steady stream of oil out the breath...
by RJC5778
Fri Jan 08, 2016 12:36 pm
Forum: Prop Talk
Topic: drying blades out
Replies: 6
Views: 1431

Re: drying blades out

digging,

I have ngrs that I purchased new locally, boat was flipped before with these blades and had been under water for a bit, also in a few rain storms while at our camp, I think I will pull them off and drill the hole as mentioned and seal the hub with some silicone....works for me, thanks guys
by RJC5778
Fri Jan 08, 2016 10:10 am
Forum: Prop Talk
Topic: drying blades out
Replies: 6
Views: 1431

drying blades out

need to pick the airboat communities brain about how to safely dry out sensenich blades, im not drilling holes so, what is a tried and true method do make sure these blades are dry on the inside?
by RJC5778
Tue Jan 05, 2016 1:11 pm
Forum: Automotive Power Only
Topic: BBC to SBC swap
Replies: 10
Views: 3126

Re: BBC to SBC swap

whats the severity of the "lock up"?
by RJC5778
Tue Jan 05, 2016 11:48 am
Forum: Automotive Power Only
Topic: BBC valve cover baffles
Replies: 47
Views: 5507

Re: BBC valve cover baffles

has anyone every run a puke tank on their airboat? ive been doin some research on this and it seems the drag boat guys like them, seems easy enough to build and very simple concept, ive heard about the 2 lines run just in front of the prop but don't like look of it. running a pcv setup now and after...
by RJC5778
Mon Dec 14, 2015 10:57 am
Forum: Automotive Power Only
Topic: BBC ROCKERS
Replies: 6
Views: 921

Re: BBC ROCKERS

gotta rem that airboat engines live in higher rpm ranges, why not go for roller tip rockers, imo they are better suited for this application, plus extra hp and less bind on your valve train....no question imo
by RJC5778
Mon Nov 23, 2015 11:14 am
Forum: Automotive Power Only
Topic: mid throttle vibration and hesitation
Replies: 13
Views: 1481

Re: mid throttle vibration and hesitation

its a brand new dyno tested quick fuel 850
by RJC5778
Mon Nov 23, 2015 8:16 am
Forum: Automotive Power Only
Topic: mid throttle vibration and hesitation
Replies: 13
Views: 1481

Re: mid throttle vibration and hesitation

I got some tike on it this weekend picking up stands and running, ran through a huge rain storm Saturday and she never missed a lick, had to run 4k the entire way to camp, 15 miles to and from, never noticed excessive vibration or stumble, I would only notice stumble after letting off throttle and g...

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