Search found 351 matches

by jinotown
Mon Aug 04, 2014 12:11 pm
Forum: Automotive Power Only
Topic: 305 small block on my 13x7.5 cotton mouth good or bad idea
Replies: 19
Views: 2715

Re: 305 small block on my 13x7.5 cotton mouth good or bad id

Spend the extra on a real aircraft engine or a car motor with reduction. You will eventually, so don't waste the time with dd car motors on that heavy hull and end up changing it.
by jinotown
Tue Jul 08, 2014 12:07 pm
Forum: Aircraft Power Only
Topic: 520 fuel injection
Replies: 3
Views: 921

Re: 520 fuel injection

I recommend it highly. If it is tuned correctly from the start and the system is in good working order, it will run great for years. FI systems get a bad rap due to very few people that set them up correctly and use well maintained, matched components. These systems are old and been swapped around a...
by jinotown
Thu Jul 03, 2014 11:23 am
Forum: Aircraft Power Only
Topic: 220 break in
Replies: 18
Views: 2119

Re: 220 break in

Be patient! Those top ends really take 20 to 30+ hours to break in. Run it normal and vary your RPM range. Don't baby it. The higher the cylinder pressure, the more the rings are forced into the cylinder walls. That helps break them in but you have to very careful with your center cylinder cylinder ...
by jinotown
Wed May 14, 2014 6:55 pm
Forum: Aircraft Power Only
Topic: Turbo my 520?
Replies: 10
Views: 1862

Re: Turbo my 520?

They are great for boosted applications as far as ability to handle it. Expect to pay huge $$$ for a properly done setup and use much more fuel (+50% at least). You'd probably be in for another prop. too. You could pitch it more but then you would be idling at 20mph. A really good setup would need e...
by jinotown
Wed May 14, 2014 6:42 pm
Forum: Airboat Tech
Topic: CHROMOLY TUBBING?
Replies: 11
Views: 1968

Re: CHROMOLY TUBBING?

CM tube is overkill for airboat riggings. The added expense and time is not worth it compared to DOM (A513) tubing. CM tube runs around 100k psi ultimate strength. After welding, the tube can be soft in some areas and brittle in others, as it is not practical to re-heat treat the entire assembly whe...
by jinotown
Fri May 09, 2014 3:16 pm
Forum: Aircraft Power Only
Topic: Cyl head temp high oil temp stays low 0470-13/ 520 conv.
Replies: 3
Views: 604

Re: Cyl head temp high oil temp stays low 0470-13/ 520 conv.

You need a shroud to move some air through the cylinders. Without one, you're asking to overheat them and drop some valve seats.
by jinotown
Tue Apr 22, 2014 2:44 pm
Forum: Aircraft Power Only
Topic: 220 loses power after 3 seconds
Replies: 12
Views: 1972

Re: 220 loses power after 3 seconds

I would check the intake tubes for leaks. That's a common problem on 220 GPU's. The standard main jets in that carb are close enough to keep it running good, just a bit lean. Do a compression check also. You may have something mechanical like a valve problem (cracked or loose seat).
by jinotown
Sat Apr 12, 2014 4:38 pm
Forum: Airboat Talk
Topic: Best deals on a new trailer?
Replies: 10
Views: 1375

Best deals on a new trailer?

My old trailer is in pretty bad shape. I'm debating whether to rebuild it or buy a new one. My boat is a 13 1/2 cottonmouth with a 520 Conti, so it is not overly large or heavy. The farthest it ever travels is about 12 miles. To redo my trailer right will cost about $800 and my labor. Any recommenda...
by jinotown
Thu Oct 24, 2013 10:23 am
Forum: Airboat Tech
Topic: propane powered airboat anyone?
Replies: 27
Views: 4155

Re: propane powered airboat anyone?

Some more basic information on propane engines...LP has 30% less btu content than gas, so you expect around an equal percentage of loss in your fuel usage. The octane rating is around 105 (R+M/2 method). If you optimize the engine build for the high octane rating, the efficiency will overcome some o...
by jinotown
Wed Oct 09, 2013 7:05 pm
Forum: Automotive Power Only
Topic: Carburator
Replies: 4
Views: 801

Re: Carburator

I would first find out why the header is glowing and why only on one side. That sounds like some kind of a flow problem with the intake, gasket seal problems, timing, etc.. It's probably not directly carb related. Even modified for a circle track car those Holleys are 500-600 cfm at best. It shouldn...
by jinotown
Thu Sep 26, 2013 10:15 am
Forum: Aircraft Power Only
Topic: Decreased thrust after adding cooling shroud
Replies: 19
Views: 2868

Re: Decreased thrust after adding cooling shroud

I ran into the same thing when I added the shroud to my 520. I ended up cutting small amounts off until I got the best compromise with cooling and loss of thrust. I have no way to calculate exactly how much but I would guess a 5-10% loss by "seat of the pants". This is far over shadowed by the excel...
by jinotown
Sat Sep 14, 2013 12:06 pm
Forum: Airboat Tech
Topic: Welding conduit
Replies: 19
Views: 5334

Re: Welding conduit

If you want to MIG your own cage then use DOM tubing instead of electrical conduit. It is more expensive initially but well worth it. Mild steel DOM is almost twice as strong as ERW conduit or tube (70k psi vs 40k psi). No galvanizing to clean off and way nicer to weld. No toxic fumes to deal with. ...
by jinotown
Mon Jul 29, 2013 1:39 pm
Forum: Gun Rights
Topic: Gun Laws for Rifles.
Replies: 16
Views: 5900

Re: Gun Laws for Rifles.

A gun can be carried in your car loaded for self defense, but it needs to be in a case (box, glove box, etc.) with some type of securing latch or snap. I have found many officers are confused about the statutes and will give you a hard time anyway. Remember this is for self defense of you in your ca...
by jinotown
Mon Jul 08, 2013 12:12 pm
Forum: Gun Talk
Topic: .22 Project rifle
Replies: 4
Views: 1190

Re: .22 Project rifle

Sounds like a great project WB! Plan a long time to complete, regardless of what wood you decide on. My first and favorite .22 had a plain stained stock that I stripped and found it was maple. I carved a Schnabel style forend, flame finished and clear coated it. A flame finish leaves a shimmering ti...
by jinotown
Wed Jun 12, 2013 6:06 pm
Forum: Automotive Power Only
Topic: What Carb for 350 DD
Replies: 13
Views: 2194

Re: What Carb for 350 DD

The overall best would be a "properly" set up two barrel 350 cfm. Make sure to have a pro fit the correct power valve, jets, idle mix and float level for your engine. They are not really plug and play. If you have a real strong engine a 500 two barrel might be OK. Anything larger will give poor thro...
by jinotown
Fri Jun 07, 2013 12:45 pm
Forum: Aircraft Power Only
Topic: electronic ignition conversion for magneto???
Replies: 25
Views: 3848

Re: electronic ignition conversion for magneto???

The valve seat problem is from high cylinder head temps. Never run those GPU's over 450 degrees, lower if possible. A cooling shroud is the best money spent for reliability. Abner uses a well proven system on the electronic conversions. Make sure to get the system with a MAP sensor. It adjusts the t...
by jinotown
Thu May 16, 2013 9:50 am
Forum: Aircraft Power Only
Topic: av gas vs pump gas
Replies: 9
Views: 1356

Re: av gas vs pump gas

A 10:1, big bore, air cooled engine needs at least straight 100LL. Even with that, be very careful on your CHT's. Make sure you have a gauge on the center cylinders and watch it. This is strictly a compression vs. octane issue. Marvel oil (or any oil) will make it worse as it raises temps in the com...
by jinotown
Tue Apr 23, 2013 1:31 pm
Forum: Aircraft Power Only
Topic: aircraft parts for central florida and temp. help
Replies: 15
Views: 1538

Re: aircraft parts for central florida and temp. help

Looking for the best place to order parts for my gpu any help would be greatly appreciated. another thing this weekend i tried mixing 93 and av with a lead additive for the fist time and i was running over 180. Before this when i was running straight av it would usually stay at 180 or under. Any he...
by jinotown
Wed Apr 03, 2013 11:10 am
Forum: Aircraft Power Only
Topic: 520 conversion carb question
Replies: 9
Views: 1028

Re: 520 conversion carb question

The aircraft carbs are sure going to be the easiest to hook up. I don't think any 520's were offered with carburetors, so the best option would be to find the correct carb for the highest HP 470. There are many different models of M4-5's, so find the right one. You don't want any possible lean spots...
by jinotown
Tue Mar 19, 2013 5:06 pm
Forum: Aircraft Power Only
Topic: fuel injection pressure on 540
Replies: 5
Views: 599

Re: fuel injection pressure on 540

The average Continental 520 specifies 9-11 psi, unmetered at idle and 28psi metered at WOT. The 540 should be close.
by jinotown
Sat Mar 09, 2013 7:51 am
Forum: Hunting & Fishing
Topic: Hog Hunt wanted in Seminole or Volusia County
Replies: 4
Views: 897

Re: Hog Hunt wanted in Seminole or Volusia County

Honestly I'm not sure I recommend anyone in this area. Think about making a weekend of it and going to the Okeechobee area. There are several guides with good results. It's really not that far, two hours-ish. D-brewster could give you his recommendation in the area as he used to do it. Thanks Yobee...
by jinotown
Sat Mar 09, 2013 7:03 am
Forum: Hunting & Fishing
Topic: Hog Hunt wanted in Seminole or Volusia County
Replies: 4
Views: 897

Hog Hunt wanted in Seminole or Volusia County

Me and two friends are looking for a guided hog hunt in Seminole or Volusia county. Two of us are experienced and one is not. We are flexible to the type of hunt. Who do you recommend?
by jinotown
Wed Feb 20, 2013 5:06 pm
Forum: Airboat Tech
Topic: weight??
Replies: 12
Views: 1179

Re: weight??

Closer to 500+ lbs.
by jinotown
Fri Feb 08, 2013 11:16 am
Forum: Hunting & Fishing
Topic: Randall made knives, Orlando
Replies: 15
Views: 1994

Re: Randall made knives, Orlando

Another great custom knife maker is Lowell Cobb in Ormond Beach. IMO, his quality is every bit as good as the Randall's but 1/3 the price. He uses 440C stainless instead of O1 tool steel. I like that I can use it on gators and not have to worry about oiling right away. The Randall's are a sure hit i...
by jinotown
Thu Jan 24, 2013 9:19 pm
Forum: Airboat Tech
Topic: Best Grade of Aluminum for Rigging?
Replies: 13
Views: 2039

Re: Best Grade of Aluminum for Rigging?

6463 is basically the same as 6063 except in it's ability to take a bright mirror anodized finish better. No big difference in structural properties. Aluminum is not forgiving to flex and vibration. Virtually every aluminum rigging I have seen has cracks all over it. Some were of the best workmanshi...

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