Top Four Powerheads for Hot-Rodding Mud Motors

BWL

BWL

Active Member
#1
#1
[video=youtube;R0tjmcYIOlE]https://www.youtube.com/watch?v=R0tjmcYIOlE[/video]

I'm about to start a new build. I was thinking of powerheads people use to build mud motors. I'm talking serious power 8k RPM and above using clones.

Okay, I listed them as follows:

4. HB non-hemi
3. Dynocams clone
2. HB hemi
1. Box Stock

What would you guys use to build a total screamer of a mud motor?
 
BWL

BWL

Active Member
#3
#3
Yeah, Honda is awesome. However if I had mentioned Honda, I'd also have to mention the Briggs Animal and LO206 motors. That would have made a top four video becomes a top seven video.
 
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OND

OND

#4
#4
I always liked the TG-1 head as far as a good flowing stock head. But my all time favorite would have to be the Honda 18cc head as far as making better compression.

TG-1



Honda 18cc Head


HONDA 14cc Head

 
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L

Latent

Active Member
#6
#6
I like the rtc-6 non-hemi cylinder head, it comes with 27mm intake valves and 25mm exhaust valves with split automotive style retainers stock as well. It's the cylinder head I run on my build.
 
BWL

BWL

Active Member
#7
#7
[video=youtube;yEUjoTsYotk]https://www.youtube.com/watch?v=yEUjoTsYotk[/video]

Dave, the Thai Longtail I run is most like what the average person over there runs. They mostly use GX390. But In Thailand outboard motors are defined by that long seven to eight foot tail regardless of the powerplant. That racing engine is nothing more than jet ski motor bolted onto the same longtail that your average Joe would use to power a V-twin.

You wouldn't consider a NASCAR race car to be what the average American drive to work everyday. So why consider a racing Thai longtail to be what the average fisherman uses to go fishing everyday on the Mekong River?

The jon boat is the closest boat we have to what the average sampan is over there. In fact I plan on building a longer narrower jon boat and mount the longtail inboard like they do to get more efficient out of the is engine.

I never said I was racing. I'm a fisherman, lure maker and importer of fishing tackle. This is what I do for a living. The problems with using a stock 200cc-clas engine is it doesn't have the power/torque that a big block 390 does. The problem with the big block is they are too heavy for my small boat. Also we Americans are a lot bigger than our Thai brethren. It's a balance. In comes the possibility of modifying a motor for more power and torque while keep weight down.

Man, I like the 18cc head as well. I need to do some top ten parts videos. Cause really these motors we make are a hodgepodge of Clone, Honda and custom parts. I plan on running a GX160 piston and a +0.80 ARC rod for more compression. In the end how much of the original motor is left, lol.

We call them mud motors over here, but Thai longtail is what people are typing into the search engines. That why I say Thai longtail now instead of mud motor. I get more views and subscribers, lol.
 
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H

Havasu Dave

Moderator
#8
#8
BWL said:
Dave, the Thai Longtail I run is most like what the average person over there runs. They mostly use GX390. But In Thailand outboard motors are defined by that long seven to eight foot tail regardless of the powerplant. That racing engine is nothing more than jet ski motor bolted onto the same longtail that your average Joe would use to power a V-twin.

The jon boat is the closest boat we have to what the average sampan is over there.

I never said I was racing.
Click to expand...
I was making a tongue in cheek (facetious) comment. I have spent several years in Thailand, and most of my life in Asia. South East Asia is teeming with this design. That engine I believe is a 750cc ski engine running the shaft off the pump PTO. It is far from stock.

I've been ferried in several variations of long tail, including water cooled four cyl. automotive Toyota engines. Pretty cool how they're balanced on the shaft so you can one-hand them. The larger versions are also used off shore, although the Gulf of Thailand is relatively benign.

Your question: "What would you guys use to build a total screamer of a mud motor?" Easy. I'd get one of the many, many, available two stroke jet ski motors, rebuild it, and use it, and not worry about the rotating assembly coming apart in my hand. I enjoy your videos by the way. I was probably the first person here to comment on them when you started posting.
 
BWL

BWL

Active Member
#9
#9
Dave, sorry, I'm on edge this morning. I've only just had my morning chocolate. Yeah, I've always wondered what it'd be like to have a Chevy small block bolted to one of the big ones.l like I've seen. Like you say, a Toyota four banger is probably much more available than big Detroit metal. A Twin turbo Subaru would be a hoot to watch.

Do they run the water in the block and let it dump back out in the river. the river water would be a lot cooler than the radiator.

My current build is just going to be a 5,000 RPM machine, basically just a box stock motor. Nothing crazy, but power and RPM comparable to a western-type outboards.

I mean really most western outboards run at 5,000 RPM and at arond 200cc produce about 10 hp, 9.8 to 9.9 most cases. Probably no reason they couldn't run 15 hp if they bolted on a bigger carburetor. While the western-types are dual cylinder's, I think these little 200cc clones should attain similar powerlevels easily and stay reliable.
 
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noseoil

noseoil

Active Member
#10
#10
Good video discussing the four choices for motors & options. That, & the Thai drag boat guys have to be a bit nuts to run that stuff like they do. Looks like a lot of fun & wanting to see more about the motor of choice & build you do...
 
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