This may be something to consider: Out of the box, from what I've seen, the Predator 670cc is very restricted from an airflow perspective. If the carburetor and the exhaust were opened up a bit, you would probably see some actual power out of it. The stock muffler on the Predator 670cc is the worst offender, imo. Robot Cantina is working on a Predator 670cc powered 60s Renault series, btw. He may have some notes for you if you want to "open the taps" up a bit.
I completely agree with your comment. I've seen a Briggs opposed twin powering a Datsun pickup back in 2007ish. A kid and his dad built it on the farm and he drove it back and forth to school. They did dual carbs and used a close to a 3or2-1 ratio on the crank. it managed 100kph on the dot. that little engine was screaming at 4500rpm tho. I've wanted to do something similar since I seen it for booting around town. I figured it started with 25hp, so with dual carbs no limiter and a bunch of diy power mods 30ish HP should be where it sits. With a 2-1 crank ratio that's like 60hp at the crank in a truck that originally only had 75hp.
My opinion on your problems with the 670, first the fuel delivery, on the truck we built like you i put a boat gas tank in the bed and ran a fuel line to the engine. Used a 2-3 psi fuel pump and works wonders. I think that will fix your hard start problem. Remove the governor to get a few more revs and hp and it will perform much better. The vibration i almost guarantee is from all those chains and clutches you have. Run a choke cable to the cab so you can get it going as well.
Why remove the governor? Unless you're going to install a new cam to shift the powerband up to those higher RPM's it's not worth it. Numerous dyno tests show these engines make less power at higher RPMs with a stock cam.
I dont have any tips (wish I did), just want to give some encouragement to keep on chuggin with this project, its very interesting, educational, and I think you are inspiring a lot of us to put something like this on our short list. Love this series!
This project is so much like my dreams it's scary! I'm bought in for the long haul, so keep the content coming. Side comment: i hope those that don't like you talking in the videos follow that advice when they make their own content on their channels. For your channel, please don't change a thing.
I have a 670 mud motor you almost always have to tune the carb super simple to do. Also bypass the pulse pump and use a inline low pressure pump derictly to the carb. Been watching alot of you videos and I'm currently about to start my own build similar to this for a pasture truck. Keep it up man and great job so far.
Thanks for the input, do you have a brand or part number of the pump you used. I found some on eBay but I trying to decide which one I need. Thanks for watching. You can send pictures of your project to ckeyfarm@gmail.com and I'll share them on the Keyfarm Facebook page.
You just make the most awesome videos Chris thank you so much I always enjoy your videos and your smile is just infectious thank you for your wonderful videos and I can't wait to see your truck with the big wheels on it. God bless you for the joy that you bring to others.
Definitely sounds like a fuel delivery problem. Get a small low pressure electric fuel pump and running the choke cable into the cab should help getting it started easier. That's pretty smart thinking with the double clutch 👍
Oh man you are getting it together, I agree with fuel pump and maybe a choke warmer to get it warmer quicker and yes bring it in side all controls that you can
No clutches needed, period. Wasting HP. The transmission has a clutch. What you need to do is make a shaft with 3 bearings. Holding the original flywheel and mounted to the Bell. Then, sprocket the output shaft of engine to the flywheel shaft. You can do this with 3 or 4 belts like a light helicopter. Has a pulley system that tensions the gearbox. I like your project. Good progress. I'm sure you thought of all of this.
The original flywheel would be a lot of rotating mass and if you didn't get it exactly straight it shake you out of the truck. It would definitely take some machine shop work.
@ChrisfromKeyfarm You need to find max engine rpm. You need those numbers. Then, you need the final drive ratio "rear gearing." Then multiply by the tire size will give you top speed. In that gear. So if you want 3rd gear to be top gear, then use those figures from the 3rd gear ratio of that trans. If you are able to pull another gear after the first figure, then that's a bonus. However, this is important for you to continue. Pencil to the paper, my friend. If that engine is not capable of turning 2500 rpms constantly no matter the load, it's because you'll shift it down to keep it there. Has to make at least 2500 rpm to get you to 50 mph, and I don't even know what gear you're using in the rear. Those big tires will eat up your engine hp..unless you have 6:10 gearing in that housing. Which I doubt would even fit inside the rear end housing. Too much , too much..do some math.. You'll be better for it.. Good effort on the project thus far.
As always Chris an absolute fantastic video and I can't wait to see your new truck. I hope you and your family have very Merry Christmas and I hope this new year is the best year of your life ever. Be safe and healthy And to you and your family always best wishes and blessings.
That’s a bummer the engine it’s working out so well. I think these engines are sold really lean from the factory. Probably re jetting the idle and main jet will definitely help especially when it’s cold. Maybe you already got it sorted out? Thanks for always making great videos Chris 😊👍
Hey Mike, I haven't got it worked out yet , but I'm going to try exactly what you mentioned along with a pair of header pipes. I've since pulled the engine off that project fitting it for the next , the Keyfarm monster truck. Thanks for checking in.
Reach out to the guy with the "Robot Cantina" youtube channel. He's currently running a 670 predator in an old renault with a rear engine setup similar to the VW Beetle. He's been working with the exhaust and carburetion of these engines to make it driveable, and you both could take notes from each other. The factory 2bbl on the 670 is made for constant rpm operation, and not accel/decel. He's having power transfer issues, and your setup looks near bulletproof. A properly jetted Khein with a spacer and intake from perfomance670 with a better exhaust would make a major difference. He's topping out in the 60 mph range. Good luck with truck.
I've seen Robot cantina, it's a great channel. I know he is running a torque converter, keep in mind that little car weighs quite a bit less than the Keyfarm truck. I'll keep working on it, thanks for watching.
@@ChrisfromKeyfarm, thanks. I think if you do a carb and exhaust swap/tune, it will go along way to making your truck run more like you want. I have future projects of my own in mind, and channels like yours are my best resource. Again, good luck. I hope any future issues you run into are easy to solve.
A toothed belt or maybe a double V-belt may be better between the Predator engine and the double clutch input shaft, there's a lot of mechanical loss in that first chain drive off the crankshaft in the form of vibration, and that will be the first thing to break.
I ran this truck with a Predator 212 and a belt and it worked pretty good when I put the 670 in the MG midget it will be v belt driven. Thanks for watching
Have you seen the hood scoop? Watch the previous video where it had the Duromax in it, it's got a wheel barrow hood scoop, you'll love it. Thanks for watching and commenting.
There's a 500cc Duromax now, 20hp. It's a single cylinder and has both the recoil and electric start. Just putting it out there. 50mph is the magic number for me, but I don't care to go to the twin and lose the recoil start.
I sent them a message asking if they would like the 500cc to be the permanent engine for the truck once it has the 5 foot tires on the back, I have not gotten any reply.
I would like to see a belt and foot clutch set up. Just pullys and belts With a belt tensioning pully in between them. All dual belt pullys. Depressing the clutch releases tension on the middle pully. The tension pully can be either flat or groved depending on whether the pully is inside or outside of the belts. Your gearing can be achieved with a combo of pulley sizes.
What if you used the stock mazda fly wheel on the pillow block bearing setup and use the new input shaft for your chain linkage. That takes the friction loss out of the dual clutches. Gives you back the usage of the clutch.
To mount that pressure plate flywheel on the new shaft would take machine work because you no longer have the back of the crankshaft and that would be a lot of rotating mass if it wasn't exactly straight it vibrate you out of the truck
Red Beard Garage is another channel you may want to checkout for info on that 670. That guy knows quite a bit about all or most Predator engines. Probably give you some tips or somewhat inexpensive ways to increase the power. But I also think you’re having a fuel delivery problem. Might want to check into a low pressure electric fuel pump and maybe a Mikuni carb setup. But I would definitely move the choke and starter switch inside the vehicle for convenience if nothing else. Cool video btw. 👍
I'm curious to see if a fuel pump with a variable pressure regulator if it would help with your idle issues. I have that motor in a generator, and the gas tank is above the motor, and it runs great. I'm enjoying this channel and look forward to more content.
Just put a mounting plate at the end and have a shaft and go through that is chain driven by the motor and at the end of that shaft have the flywheel which is connected to everything just like a regular car. You're going to dump more money into buying go-kart clutches and everything. And those clutches are not made for that to go with that fast. It's easier just to use the flywheel the clutch everything that came with the original setup and just have a shaft connected to the flywheel just like you would have a flywheel on the engine crank shaft. You would have to weld up a metal rig so that it would hold the engine up high with a chain going down to drive shaft and at the end of the drive shaft again at the end of the drive shaft would be the flywheel.
I disagree you would lose so much power rotating a clutch and a flywheel and getting it centered would be very difficult. My projects are not hard on the clutches.
Brakes need a vacuum to work on the old cars but that 2nd clutch wont help cause if ya look insde them they are designed for a motor to spin 1 way but ur also loosin torque in the chain but u HAVE to have the tank hgher cause it has to work like a syphon so it cant get the fuel,regap the spark plug can also give ya more power but then gettin a better quality spark plug will help But remember the motor only does 3,600 rpm like the other motors you have put it so mount the motor lower so the shaft nearly is level with the actual gear box will improve it alot ;)
I do appreciate the comment and you watching, however a few of those points you made are incorrect. Older vehicles have brake boosters to help brake, you can brake just fine with a strong leg 🦵. These clutches are bi- directional , I made sure they were when I ordered them because I knew how I was going to mount them. The engine has a pulse pump that pumps fuel up from the tank so it doesn't have to be mounted above the engine, however it may be inadequate. Your comments about spark plugs are accurate. My brakes were stuck because this truck hasn't been driven in a while, which is common for old calipers that don't get used a lot.
If the engine were mounted straight to the transmission as you suggested it would have to have the original clutch and flywheel, which weighs a lot more than the chain and clutches. It would also burn up the clutch trying to get it to move, the bottom sprocket gives a mechanical advantage that allows the lower power engine to work.
I haven't seen enough of your videos to know, does your setup work with automatic transmissions? I just subscribed ,so maybe you've already covered this.
In an electronic trans you could make it shift with a set of switches a lot of the time but the line pressure would be 100% all the time. Another issue is the torque converter and the way it works may not work with gear reduction prior to it. You likely have to remove the converter and put your power directly to the input of the trans... Not sure that's really possible@@ChrisfromKeyfarm
a 670 twin should be loaded with torque and have at least 80HP . . . as mentioned try remapping and open up the intake and exhaust, I think they are designed for water pumps so like a lawn mower they're governed and have an auto torque idle up, replace intake with a sportbike setup, CV carbs or FI
I was jist going to recommend smaller skinnier tires and wheels for less rolling resistance and to add an electric fuel pump with an adjustable regulator. Keep weight light as possible for brakes just use the rear s with a parking brake lever ma be
think the dual clutch should work you might make the second clutch grab at a higher rpm that way you have a little more slippage (they grab in stages ) so you can run a higher gear from standstill just checked the price for one of those v2 engines , 1800 bucks (in the netherlands) ..... wow thats not cheap , a rebuild smart engine with a core exchange is 700 bucks and a whole smart with some mecanic work is about 750 bucks over here a smart car might actually make a nice base for a smaller predator engine , its running a 700 cc engine in stock form and are pretty light as for adding power and making adjustments , look at robot cantina , hes working on a car with a v2 predaior in it doing different adaptions about the bigger wheels.... too bad you havent got another set , one thing you can do is use two engines one mounted in the back and one in the front and drive each axle with one motor m should work ok if you eather use a direct drive or find a way to work two gearboxes at the same time with the dual clutch setup you could allso lengthen the jackashaft and run both engines or run them side by side with a single chain across and on the same sprocket through the dual clutch set up , will need to do some fancy stuff with the electronics as i seen someone done it before and he needed seperate deadmanswitches as the ignition of the one caused misfiring in the other when he put everything in series on a single switch
Me I'm the other way I love tourqe converters and I don't like centerfugal clutches.... much faster takeoff and no burning out the clutch and not being all sluggish on takeoff...
wow yeah i would have thought it would have done better . i really dont want to think its the engine . i could be wrong . i watch a guy doing the same thing with a car . you should or maybe have watched him to see what hes doing . his channels name is robot cantina . hes doing it in a old Renault . he has got it up past 60 mph . he uses a torque converter . and i think that might be your issue . it takes a little while for the torque converter to get to top speed but it allows the engine to work through the gears of the torque converter plus it has the gears of the manual transmission as well . your running more of a direct drive of sorts . i think them clutches are robing power from you . but i could be wrong . i just cant make sense of the power loss other then that . hey if anything else maybe get ahold of robot cantina and swap some ideas on it maybe you can work it out . maybe put that 670 in the mg .
I know of Robot cantina, it's a fantastic channel, I've watched several of his videos, only a couple on the 670 Renault though. I did see that he is running a torque converter, but keep in mind that Renault weighs a lot less than this pickup, even missing the bed. I'm going to look into an electric fuel pump as several people say that is a problem. Thanks for watching!
How could I connect or adapt a motorcycle or sportbike engine to automotive transmission? Or would that even be possible? Ideally, I would be using a 1000cc or 1300cc sportbike engine and either a 200R4 or 700r4 automatic transmission inside a small lightweight car like a mazda miata. Thanks for any thoughts or advice.
A sport bike engine to a manual transmission is really easy you can do it just like I've done these and automatic transmission is a different story however.
@ChrisfromKeyfarm Thanks for your insight and recommendations. I was involved in a severe car accident, therefore I can no longer control my legs and feet. So I can no longer drive a stick shift transmission. I have noticed some sprocket to driveshaft adapters. I do not know if that would help me much. As a driveshaft isn't really a bellhousing. Unless there are companies or people who might be able to make something work. Although I do not know of a company that could look into this for me.
@ChrisfromKeyfarm Currently, I drive a minivan with handcontrols for the brakes and accelerator. However, it has an automatic with power steering and power brakes. It would be really easy to replicate since it just has a linkage with steel rods going to the brakes and accelerator pedals and a push-pull horizontal bar. But like I said, it has an automatic transmission.
The only torque converter I own doesn't work as well as the worst clutch I own they have their place like on go-karts and mini bikes but not really here.
thats so awesome dude it works like its ment to be, just needs a little bit of an exhaust, theres a whole ton of different parts on ebay to prep up the power, pretty much enough parts to start out very very mild an work your way to wild lookn an moving real well for bone stock, stay blessed chris !
@@ChrisfromKeyfarm yea just to make sure it stays rich an cool, im sure you wont have a problem finding the one youll need ide keep it stock till ya have everything you need to take it to the level you want it an still keep it in safe parameters. stay blessed chris we hope you have a blessed day
