Search found 978 matches

by Slidin Gator
Wed Feb 28, 2018 11:00 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Brother Russ, I am surprised you would post this graph. I see you got it off their website, so the bull**** is theirs, not yours, but . . . really? http://www.ulpowersa.co.za/index_files/image710.gif Do you not see a very fundamental flaw here in this graph for this engine that not only defies the ...
by Slidin Gator
Wed Feb 28, 2018 10:19 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

OneBFC posted earlier: Well, I will just leave this here and you guys can finish figuring out what's going on from there. This is the Version 3 pt II 502 from the above examples. I mean, you can see that you make more thrust with 545 lbs of torque than you do with 594 lbs of torque. I think it's pre...
by Slidin Gator
Tue Feb 27, 2018 2:13 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Changing the gear ratios on my spreadsheet is easy. Adding a different motor takes the time.

Here is the same 502 comparison, but with the 3 gear ratios being discussed now.

Image
by Slidin Gator
Tue Feb 27, 2018 1:03 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

IMO, the fact remains that 2.12 gear isn't enough to attain the end he is after. He needs at least a 2.3x and maybe more. Given the power required, he will be FAR better off with that 502 being a 540; again given his intent in the original post. A 502 - 2.12 combo can rock a 16 maybe 17 ft. boat; a...
by Slidin Gator
Tue Feb 27, 2018 11:03 am
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

CMB asked: This is very useful info. Can you also post the HSP curves? I think this will help the discussion. Thanks. Man, you are going to make me have to get back onto my soap box, and I don't want to do all that typing. I'd rather draw curves in the sand at a cabbage head, or in a bar on cocktail...
by Slidin Gator
Mon Feb 26, 2018 10:24 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Ladyblackwater, Thanks, I can sum up my experience with big block gas motors as "0", so I am not going to argue over where the motor wants to live. This is good input, but think about this. The primary reason that I leaned to the high HP motor with the tall gear is because it wins on prop torque, bu...
by Slidin Gator
Mon Feb 26, 2018 9:35 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

I have had time to look into some 502 build option specs. In particular the following two web sites have dyno test data for different build configurations: http://www.fourwheeler.com/how-to/engine/131-9809-gm-performance-parts-502-torque-motor-buildup/ http://www.chevrolet.com/performance/crate-engi...
by Slidin Gator
Sat Feb 24, 2018 7:44 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Re: 502 power VS torque Postby nolaboat » Sat Feb 24, 2018 6:49 pm Slidin gator. Thanks again. Ur rigjt about the 502. I have 2 of the from a boat. Sending one off in two weeks to start the rebuild. I do have a ls2 ready to go but didnt think i would work well in a 21ft boat. Funny u say diesel. I ...
by Slidin Gator
Fri Feb 23, 2018 6:17 pm
Forum: Aircraft Power Only
Topic: 0470-13 help
Replies: 11
Views: 2265

Re: 0470-13 help

verify gauge - use a temp gun and check the inlet/outlet of your oil cooler X2 and check your cylinder temps at the exhaust valve with the same gun too, all idling hot. Any anomalies? You did not mention anything about the crankcase vent tube, what's going on there? Is it blowing or smoking signifi...
by Slidin Gator
Fri Feb 23, 2018 3:05 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Nola, I think page 1 of this thread covered this pretty well and the general agreement is that you want more of everything, more power, more torque and more prop. An O-540 is a great motor, but it's way outmatched by your requirement! Can we assume that you started this thread asking about a 502 bec...
by Slidin Gator
Fri Feb 23, 2018 12:23 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Thanks Kwan, I saw you did that with the original torque curve and was going to ask you how to do that, but it was too late to bother last night.

Can you give a run down on how to post pics directly into the post? Perhaps a different thread on the subject would be useful.
by Slidin Gator
Fri Feb 23, 2018 9:33 am
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

Set ups C, D and E added. Note that I came up with the torque figures by assuming an engine torque of 600 ft-lbf at 5,350 RPM at the engine, then decreased that by an 80% efficiency value for the gear box. I think the engine torque is high and perhaps the gear box efficiency is better. https://south...
by Slidin Gator
Fri Feb 23, 2018 9:01 am
Forum: Automotive Power Only
Topic: How to build a bullet proof 350 with 400 hp
Replies: 24
Views: 2577

Re: How to build a bullet proof 350 with 400 hp

If piston ring is broken you should have a bunch of blow by and oil temp would run hotter. You talked about PCV issues previously, which might match up with the blow by. Run the leak test you mentioned. Pull all plugs and turn the engine through full cycle with the leakage tester running. Leakage te...
by Slidin Gator
Fri Feb 23, 2018 8:50 am
Forum: Airboat Tech
Topic: Alternator problem
Replies: 4
Views: 826

Re: Alternator problem

It sounds like an internal short for sure. It should not get hot with the unit disconnected.
by Slidin Gator
Thu Feb 22, 2018 9:08 pm
Forum: Airboat Tech
Topic: Alternator problem
Replies: 4
Views: 826

Re: Alternator problem

What kind of alternator are we talking about? Single wire or remote control? You said you unhooked the main wire and it gets hot, were any other wires connected (control harness etc.)? Finally,this sentence does not make sense to me: I have also tryed leaving Petco switch on and boat to see if there...
by Slidin Gator
Thu Feb 22, 2018 7:54 pm
Forum: Aircraft Power Only
Topic: plugs and wires
Replies: 3
Views: 1091

Re: plugs and wires

snow bullet, I wish you had said you had a Lycoming 540 with Bendix 20 mags and wanted to switch from AV to auto plugs, I'd gladly swap you my set up! I included an attachment showing how I built my wire harness, if you really want to go down that path. Honestly, I learned my lesson though since I s...
by Slidin Gator
Thu Feb 22, 2018 6:53 pm
Forum: Aircraft Power Only
Topic: What weight oil for Lycoming 0-320 H2AD?
Replies: 19
Views: 2571

Re: What weight oil for Lycoming 0-320 H2AD?

I am not intimately familiar with the 320, but I am pretty sure it is similar to the 360/540. In which case they are flat cam followers, pushing on a hydraulic lifter, pushing on the push rod. You do have to bleed them, I use a small brass rod (something softer than the steel ball inside). The proce...
by Slidin Gator
Thu Feb 22, 2018 6:42 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

CMB, thanks for the prop curve, I have put together some graphs using this curve to further explain my point. For these curves, I used the WOT thrust and RPM data point (1,860 lbs thrust at 5,350 engine RPM) and back calculated the rest of the curve using a simplified Y^2 formula. So it does not exa...
by Slidin Gator
Wed Feb 21, 2018 10:18 pm
Forum: Aircraft Power Only
Topic: What weight oil for Lycoming 0-320 H2AD?
Replies: 19
Views: 2571

Re: What weight oil for Lycoming 0-320 H2AD?

That is good info for me too, I learn something everyday thanks! I see that the 100 is 2X the weight, so the 80 is a 40 weight oil, that answers my earlier question. This link covers the Shell https://www.shell.com/business-customers/aviation/aeroshell/piston-engine-oil/w100plus-w80plus.html Here is...
by Slidin Gator
Wed Feb 21, 2018 8:00 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

I tried to remain platform agnostic, specifically using Engine/gear as a combination. All discussion of torque is at the prop. I agree with Airduds that the prop does not care what the prime mover is, but I will qualify that as the prop does care what the torque characteristics are, as seen at the p...
by Slidin Gator
Wed Feb 21, 2018 6:26 pm
Forum: Aircraft Power Only
Topic: What weight oil for Lycoming 0-320 H2AD?
Replies: 19
Views: 2571

Re: What weight oil for Lycoming 0-320 H2AD?

You want aviation grade 50, Weight oil. Do not use 50 weight automotive engine oil (unless in a pinch) as the additives are different. The most common is AeroShell 100W, it is also the most expensive. Usually about $75 a case at most airports and some other places you can get AV gas. I don't really ...
by Slidin Gator
Wed Feb 21, 2018 4:29 pm
Forum: Automotive Power Only
Topic: 502 power VS torque
Replies: 177
Views: 16210

Re: 502 power VS torque

OneBCF HP. doesn't move a boat. Torque does, horse power sustains the torque. The best motor you can get is one that pretty much goes square around the Rpm you want to run. This meaning the HP and torque are about the same numbers at let's say 4800rpm (if that's the range you are looking for) If yo...
by Slidin Gator
Fri Feb 16, 2018 9:53 pm
Forum: Aircraft Power Only
Topic: Update overheat and detonation ! Thank you!!!
Replies: 6
Views: 1256

Re: Update overheat and detonation ! Thank you!!!

Flounder, Cool, glad to hear it. Now you know what you are working with. That is a hell of a big a## boat for a 4 cylinder aviation motor to push, can I assume you are fishing the flats vs. a bunch of dry running? If so, that is a good, economical motor for sure, but it is going to work. With a good...
by Slidin Gator
Tue Feb 13, 2018 10:38 pm
Forum: Automotive Power Only
Topic: Airboat Engine Builds - Automotive
Replies: 74
Views: 8977

Re: Airboat Engine Builds - Automotive

I’m new here, but I’ll throw my hat in this ring. I will go with Loudmouse, Swamp and CMB on the extreme application. Who reading this normally throw’s mamas minivan into second gear and runs 3-4K RPM with WOT excursions to 5+ for minutes/hours? Since I could not justify my own hot rod, a tow truck ...
by Slidin Gator
Tue Feb 13, 2018 8:03 pm
Forum: Aircraft Power Only
Topic: Overheating and detonation
Replies: 33
Views: 3430

Re: Overheating and detonation

Flounder, I agree with that plan, particularly using a buddies tail number (or a made up one as suggested). At $500+ per cylinder, AV gas is pretty cheap in my book! Getting it is the hassle. I do keep a couple of bottles of Octane boost and lead substitute in the boat, just in case I need to bum fu...

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