Installing GX160 lifters in the GX200?

#1
So I am getting to the point soon were I will be buying lifters for the clone I am building and see that the 160 lifters are a little lighter. I also noticed that the lifters are only guided by the block with no inserts so its straight on aluminum. Guessing the lifters are shorter and am wondering if this causes a problem with wearing the block out in the lifter boss or if there is any long term problems with running them in the 196 blocks? I am guessing that the base of the cam in the 196 and the 160 have the same distance to the lifter boss and that the lifters are just shorter so they can use the same pushrods in both motors. Am I correct? Are the 160 lifters fine to use in a motor that is going to have a max RPM of around 6K for long term use? I have to buy pushrods anyways and the cost is the same no mater what length I get. Same with the lifters. Any one running these?
 
#2
I usually run them when the head is milled .100 or more... ran them for seasons at 8000+ rpm... stock Honda pushrods... no issues...
Really depends what ya have around to build a motor...
Never used them because they were lighter though???
 
#3
Ya according to NR racing they are suppose to lighten the valve train by about 7%. They sell longer pushrods for the swap. I will weight the pushrods and lifters when I buy them and compare when I pull a stock motor apart. Good to know they live at high RPM thanks for the help.
 
#4
Well found something interesting after posting this. I plan on weighing every part I get and I have 2 aftermarket stainless 27mm valves and a 24mm exhaust. My exhaust valve weighed in at 22.19 grams with the intakes both being different weights. One was 23.5G and the other 25.78G. The lighter one looks like it has more undercut to it and the face of the valve is not as thick. Both intake valves are the same height but being that the heaver one has a thicker face it looks like it will install with a lower retainer height than the lighter one would. The exhaust dose not stand as high as either valves. Could not find my feeler gauge to check how much lower the exhaust was but non of the valves I bought said anything about being long or shorter than stock so I assumed they were stock length. I bought an intake and exhaust from one company and the other intake from another. I think I got the heavy intake and the exhaust from OldMiniBikes and the light intake from a carting company that I cant remember the name of off the top of my head. I will ask the machine shop what intake valve to use when I have the head worked on. Interesting that an intake valve could be about 10% lighter than another one. Going to ask my machine shop which one they think will have better low lift flow. Plan on checking install height after every thing is put together, hope I got stock length valves.
 
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trinik7597

Active Member
#5
That's what happens when you get mismatched valves ... Usually the flat faced valves are the same but not the concave ones ... And you only need to lighten the valve train using 160 lifters and longer rods when you run champion rockers to compensate weight ...
 
#6
That's what happens when you get mismatched valves ... Usually the flat faced valves are the same but not the concave ones ... And you only need to lighten the valve train using 160 lifters and longer rods when you run champion rockers to compensate weight ...
Who sells concave valves? I would have bought a set of those instead. What do you recommend for light weight rockers? Was thinking of going aluminum roller rockers but they look a lot heaver than the stock design. Also thought about the steel, Burris rockers.
 
#7
Why are you so concerned with weight???
You say you want stronger pushrods??? What is wrong with Honda pushrods??? They are pretty darn strong and lighter than the moly ones.
 
#9
Going to run roller rockers so need a different length anyways. Stuck on the chrome molly rods. I am increasing the valve spring pressure and almost doubling the RPM of the motor and like to over build on valve train when I build a motor a little. The rockers are a little over kill but cool to have. The other parts I have to buy anyways so the extra cost of getting stronger stuff dose not add much to the build. The push rods might be heaver but there stronger too. The lifters on the other hand, if one set is lighter and there is no other trade off and cost is the same for both why run the heaver set?
 
#11
I have a UT2 head with stainless valves. The intake valve is getting opened up to 27mm from the stock 26mm. Very light port work. Pretty much just smoothed out the sharp edges were the port transitions in to the bowl area and rounded the short side radius. Think I am going to have NR grind me a cam. The lift is .280" and duration at 0.050 is 220. I am thinking of having it ground with a 102 ICL and a 106 LSA. Very mild and and lots of torque. Probably do 1.1 rockers if I go with the above cam and 22 LB springs. Might have the head milled slightly to get the combustion chamber to around 16cc as I want the compression to be in the mid 9 range. The calculators I am using are saying with the head, piston and head gasket I want to use that I will be in the high 8s and this is still too low. Will be using an old style predator piston and I believe the dish is 4cc. My block is bored to use a predator piston and will be using a +.020 rod and Honda 196 crank. This motor is being build by your input and my stubbornness. Might play with cams later depending on how it drives.
 
#12
The dish is closer to 3cc .. if you are building a 208 2.756 bore Honda stroke ... I would use a hemi flat top piston rather than the dished predator to lighten the rotating assembly ... Your cam choice sounds OK depending on the type of riding you plan on doing ?? I would also use at least a 26# spring if not heavier ..
 
#14
Compression height on the hemi flat top is different than the dished piston however .. but it is a much nicer lighter piston if you are not going with an aftermarket like a wiseco setup ... I said 26# or higher ... With a .280 lift or higher I would probably run single 32's but that's jmo !!
 
#15
Are you running 1.1:1 or 1:1 rockers? If 1.1:1 than that would put your lift at .308 and stronger than 22# springs are in order. Trinik, is it better to gain that extra lift from ratio rockers or by a higher lift cam? I think if getting a custom ground cam I would get all the lift from the cam.

NR has two different flat top pistons with predator bore:
.550 compression height

.570 compression height
 
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#16
Are you running 1.1:1 or 1:1 rockers? If 1.1:1 than that would put your lift at .308 and stronger than 22# springs are in order. Trinik, is it better to gain that extra lift from ratio rockers or by a higher lift cam? I think if getting a custom ground cam I would get all the lift from the cam.

NR has two different flat top pistons with predator bore:
.550 compression height

.570 compression height
I was planning on running the .570 piston. I don't have a rocker arm picked out yet. I will wait on springs tell I get the cam so I don't have to buy them twice. Honestly my personal thoughts are that its better to get your lift from the rocker. Your not excelerating the lifter and push rod as fast. A lot of VW air cooled builders like to use rockers for the extra lift over cam. I think the rockers I want are actually 1.0:1 not 1.1:1. Thought about getting a .230 lift cam and running 1.2:1 rockers instead of the 280 lift cam with the same ICL and LSA as the 280 cam I am thinking of. I think the 280 would make more torque but the 230 would make more power from the mid range to the top end. I want to have power going up hills in the woods on trails with the motor but I want it to be fast on the flats. Will be driving on dirt more than anything. Will be doing some blasts down the street too though. Only rode dirt bikes a few times and never owned a mini so I am sure even a mini with a stock tune and governor removed with just a flywheel, valve springs and a billet rod would have been faster than I need.
 
#17
Have you worked out your math yet on the motor? piston to valve clearance?piston to head clearance?
Remember the devil is in the details. Remember the P's




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#18
No but its too late anyways. I already ordered my parts. Got a predator dished piston and just bought the CL1 high torque cam. I plan on running 1.2 ratio rockers with it. Intake lift is .224/.230 and duration at 0.050 is 219/222. This will put lift around .269/.276 I should be safe there. I was going to run an aluminum ACR flywheel and PLV ignition with a 6,100 RPM rev limiter but me and a friend decided we are going to try a NOS kit on the motor and don't want to bounce off a rev limiter while spraying the motor so picked up a Honda aluminum. Still going to get the 160 lifters and chrome molly rods but will have to be on another payday. Wanted to do a billet side cover and full roller rockers but I want to see this thing built soon and will probably just get some billet steel rockers and a regular side cover for now so I can speed the build up.

I still have to get the head worked on and think I might have them take .030 off the head and see were that puts compression. Going with a thick head gasket .040 or .045 and milling the head .030 will put head at close to stock height. I think I calculated the compression with a .040 head gasket at about 8.8 compression if I am correct and would like to raise it a little. I bought a .020 rod and don't know where the piston will be tell I test fit every thing. I might end up going with a much thinner head gasket depending on were the piston sits when I am done. I am hoping it will be sitting .005 below the deck. This is were I calculated it with my compression calculator. When I get some more parts I will mock things up and take some measurements. Still a little way away from being able to put together. Need to buy a few tools too.
 
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