Shred head VS Tillotson cylinder head -T225 showdown

Added: 2026-05-21

[00:00:14]So, which cylinder head would perform better on a Tilson 225? A shred head or a Tisonson 225 cylinder head? I mean, they're both similar in cost, but which one would be the better performer? So I have this Mega Moto 80105 with a Tilson 225. So this has a billet flywheel, billet rod, a Isi 330 cam, a 24 mm flat slide, a header pipe, and then the Tison 225 cylinder head. Then it's running a Noram disc clutch, 13 on the clutch, and a 67 on the rear sprocket for a 5.15 to1 ratio. So, I'll take this bike out for a 0 to 30 and top speed run with this setup to get some baseline numbers.

[00:01:03]And then I'll come back and swap on the shred head and I'll go back out and do the same test and we'll see if there's any difference.

[00:01:30]Yeah, it's been so long since I've ridden this bike. I can't remember how quick or slow it is.

[00:01:46]It seems like it gets it on pretty good though.

[00:01:52]All right, let me see if I can knock out a 0 to 30 here. I'll do a couple of them just to get a good baseline on this bike.

[00:02:04]See if I can get this draggy hooked up.

[00:02:08]Okay, the first 0 to 30.

[00:02:17]That thing has a 0 to30 pretty quick.

[00:02:21]So, first 0 to 30 was a 3.77.

[00:02:26]Let me back that up real quick.

[00:02:38]What is it? 3.77. See if we can back that up.

[00:02:48]Okay, 3.82. So, it's really consistent.

[00:02:51]All right, let's grab a top speed run real quick.

[00:03:04]They get some speed pretty quick.

[00:03:33]Yeah, I can't remember what the speed was on with this fuel ratio.

[00:04:10]So, we did about 60 so far.

[00:04:14]Make sure nothing's falling off.

[00:04:31]This thing picks up speed quick.

[00:04:53]So, we got our baseline numbers. We did a 3.77 best 0 to 30 and right at 60 mph with this gear ratio. So, that gives me a decent baseline anyway. So, now I'll pull the tillis head off and pop on that shred head and we'll see what happens.

[00:05:12]So, the port is slightly wider on the shred head. It's almost like a Predator 224. So, we'll see if I have to oblong my flange. So, I'm not going to be able to use this intake manifold because the shred head has a different style port.

[00:05:29]Use the same exact plug.

[00:05:34]So, I will swap on these shaft mounted rockers onto the shred head to make everything even.

[00:05:51]So, there's the Tison 225 cylinder head and then we're running about what 45,000 head gasket on here. So, looks like the shred head's going to bolt directly onto the Tison without any issue because it has 10 mm dowel pins. So, we got tins on here. So, that thing should bolt directly on there without any issue. So, the shread head definitely has a smaller combustion chamber than the tillis. So, you have a what an 18 cc chamber there and then a I think it's a 22 on the tilly. So then you have a 25 27 on the tillis and then a 24 and a 28.5 on the shred. So then you have the ports which are a little bit different on the tilly versus the shred head. [music] You have more of a round port on the shred. Then you have that the dport on the tilly. And then these are both running 26lb springs. This one came, the steel valve version came with the 26lb springs. Then you have the automotive style retainer keepers. Same thing on the tilly. Tillison, even though it has a little bit smaller intake valve and then a little bit bigger exhaust valve, it also has five mm stems versus the shred heads 5.5s.

[00:07:09]So that's another difference. Exhaust port, the D style port on the tilly. You got the D port on the shred. This casting feels nice and heavy, I tell you that. Feels a lot heavier than the tilly. And then for the shred head, I got this built intake manifold. It's a bolt to that round port. Then you got the standard Dport intake.

[00:07:32]So I'll swap on these shaft mounted rockers onto the shred head because I had the shaft rockers on the tilly to make everything even for the test. So, either of these heads have any port work, [music] so it'll be a nice even test. They They are factory stock as far as porting goes. So, I'll throw the shred head on there and I'll use a 45,000 head gasket instead of a thin shim head gasket. That way, this thing doesn't get any extra compression to mess up the test. I mean, it's already going to get extra compression anyway with the 18 cc chamber. So, this thing should go right on here.

[00:08:12]throw a little oil on these studs so I can get a decent torque reading on these things.

[00:08:22]So on this shred head, the rocker arm perch is just slightly higher than on the Tison head. So the push rods are a little bit too short, the stainless push rods. So I'm going to have to use this chromoly push rod that's slightly longer. So I think it's a little bit lighter even though it's longer. So, we might end up with a little bit of an advantage with the chromoly push rod. I mean, a lighter valve train. It's going to be less chance of valve float, but I don't think it's too much lighter. So, let me weigh these and find out. The chromali push rod is definitely going to be lighter, but it's also longer, [music] so that'll help make up for some of the weight. Let's see here. So, the chromali push rod is 12.4 g and the stainless push rod is 12.9. So, it's only like a half a gram more. So, not that big of a deal. I mean, it is a little bit lighter. So, these are 5.374.

[00:09:18]So, they're just slightly longer, but they'll fit in the shred head with the uh shaft rockers. So, those stainless push rods were just slightly too short, but I think these will work a lot better in here.

[00:09:34]a little loctite on these studs just to make sure.

[00:09:38]The valve stems on this red head look a little bit longer too compared to the tilly. So that's another reason why it kind of changes up the valve train geometry a little bit.

[00:09:49]So at some point I'll have to vent the crank case on this thing. So I have the fittings here and on the side cover to reduce the ring flutter and the crankase pressure, but I can't do it right now.

[00:09:59]It'll uh it'll mess up our uh test.

[00:10:03]Got to try to keep everything as consistent as possible. Let's see if my pipe will go on here without having to oblong this flange. I mean, it already is. It already has the holes kind of beveled out. So, I think it might fit right on here. Let's see.

[00:10:20]Oh, yeah. That's perfect. Drop right on there. So, that should pretty much do it. I mean, there's only one variation, and that's a slightly lighter valve train. What? About a half a gram for the push rods, but everything else is the same. carburetor, header pipe, spark plug. So, it should be a pretty even test, a pretty fair test. Even has the same shaft mounted rockers. So, I'll drop this thing down and I'll get this draggy hooked up here so we can get some nice accurate numbers. So, last time around with a tilly head, we did 3.77 best time from 0 to 30 and then 59.88 top speed.

[00:10:59]Heat.

[00:11:18]Heat.

[00:11:37]Sounds pretty sweet with a shred head on here.

[00:12:02]That's pretty snappy with a shre head.

[00:12:08]It feels quicker, but I'm not totally sure. Guess we'll find out. Let me hook up this draggy here. See if I can get some satellites. Okay, let me see if I can get a 0 to 30 big V3.77 with the shred head.

[00:12:29]Oh yeah, I think I beat it. First time out. Not even warmed up. 3.65.

[00:12:36]So, it's a little bit quicker so far.

[00:12:38]Let me try to get this thing warmed up a little bit.

[00:12:55]Oh, yeah. Moving out pretty good.

[00:13:08]Yeah, it feels a little bit more snappy with a shred head.

[00:13:12]See if I can get this draggy hooked up here again.

[00:13:24]All right, so we got a little bit more heat in this thing. So, see if I can beat that 3.65 a 3.61 61.

[00:13:43]So, it's consistently quicker than the Tilly for sure. Now, let me see if I can grab a top speed here. At least up to the top of the neighborhood.

[00:13:52]Make sure nothing's falling off.

[00:14:04]All right, run up here to the top of the street and we'll get a top speed on this.

[00:14:23]Heat. Heat.

[00:14:43]We already beat the top speed going up the street uphill.

[00:15:10]Oh yeah, it's quicker and faster. We already did 63 coming up the hill.

[00:15:22]I definitely like the shred head.

[00:15:25]I mean, this thing could use more gear.

[00:15:26]If I threw more gear at it, it' definitely have a lot better top speed.

[00:15:31]But at least with this gear, I can reach maximum RPM, right? To the point where it's going to float the valves.

[00:15:42]That picks up speed quick.

[00:16:06]Heat.

[00:16:12]Heat.

[00:16:25]Oh yeah, this bike definitely likes that shred head. So with the tilly, we did 3.77, 0 to 30, and 59.88.

[00:16:33]With the shred head, we did a 3.65 and a 3.61. Almost a couple tints from 0 to 30, so it's definitely quicker. And then gained some top speed. 62.90.

[00:16:44]Yeah, you can definitely tell this thing's more powerful all the way through the RPM band. It definitely has a lot more pull or more torque all the way up through the RPM band. And it revs all the way till it can't rev anymore.

[00:16:56]So, I think the bike could have been a little bit quicker from 0 to 30. If I would have tightened up that clutch a little bit, adjusted it to where it would grab a little bit sooner. But, I didn't really want to mess with it between the head swaps. It would have kind of messed up the test. Yeah, I definitely could throw some more gear at this bike and it would have a lot more top speed, but I threw this gear on here so I could meet the maximum RPM on each head. So, the Tilly 225 definitely likes the tread head, especially with a 330 cam. So, with a little bit more gear and a little bit more carb, this thing would definitely have a great top speed.