| Author | Message | ||
     Tombo |
I was considering 107 options for my Fat Bob and now see that Harley makes bolt-on 110 cylinders (no boring the cases). They use steel liners instead of iron. Wondering if anyone has heard anything god or bad about these? | ||
| Tootal |
I would put them in torque plates and measure them for being round and with no taper. Many of the squauking chicken parts are not as good as having stock cylinders bored by a good machinist. | ||
| No_rice |
they should be just fine, we will be putting a few of these on some of our floor bikes. and in 10 years of being at the hd shop i cant really think of to many problems with the 100's upon 100's of screaming eagle cylinders or motor builds we have put out. | ||
| Phelan |
Personally I would go with the 107" kits like what we sell here at the shop just because the better quality components. SE parts are fine, but the 107 kit has Axtell cast iron cylinders, which give the absolute best ring seal, and Forged CP pistons, along with multiple dome sizes for different compression options to better match different cams. | ||
| Tootal |
My comments come from a local engine builder who I have great respect for. He's been building Pro Stock engines since the 60's and also built many a HD engine. He has his own flow bench and has tested SE heads and they flow only slightly more than stock heads and he's also measured SE cylinders to find them out of round once in torque plates. He's very anal and I can say when he finished honing my cylinders they were within .0002"! I'm sure the engines built with the SE cylinders run fine but when it comes to using oil and longevity they could be better. I know there are several guys who spent a lot of money on all the SE upgrades, heads, 110" cylinders and cams, at the dealership only to get left in the dust by one of his 103" motors. He has even taken his bikes in to be dyno'd by the dealer and when he tells them the size of the engine they call him a liar! And he just smiles! His favorite personal engine was a square engine with a 4 3/8" bore and stroke. It dyno'd at 138 HP and 142 ft.lbs of torque with a beautifully flat torque curve. So my point is that a good builder can choose the right head flow to cylinder size and proper cam to make a much better engine than the parts catalog at the local shop. | ||
| Snacktoast |
We used to have problems with SE cylinders being inconsistently manufactured. We would often torque plate them (4.060" bore, among others) and find them to vary .001-.0015", often with taper or at times out of round right out of the box! This is pretty much unacceptable in the performance parts world - stuff you would never see from S&S, Axtell, Revolution Performance, and others. Generally speaking, there are better options than SE parts for the educated engine builder that isn't after a "kit". (Message edited by snacktoast on September 05, 2015) | ||
| Stevel |
There might be a misunderstanding here. Torqueing only causes bore distortion if the head bolts thread into the cylinder. If the head bolts or studs thread to the engine case, the torque is absorbed in the case, not the cylinder. Also, the use of the torque plate is to distort the cylinder during manufacturing to replicate in use torque. | ||
| Tootal |
I'm not understanding you Steve. An old shovelhead engine had it's cylinders bolted to the cases and the head bolted to the cylinders. You didn't need to use torque plates on these cylinders since they were not being squeezed. In the evo engine they use the same design as Ferry Porsche. The cylinders are squeezed between the heads and the cases. This can deform the bore so torque plates are used to replicate the deformation at a certain torque so when it's installed on the engine it will become round and straight once the same torque is achieved. | ||
| Stevel |
Tootal, I think you have it backwards. The shovel needed deck plate boring, the EVO doesn't. Think about the physics involved. There is a reaction for every action. In that light, torque applied to one end of a bolt is counteracted on the other end by resistance to the applied torque. This is what causes bore distortion, not compression. Now compression studs and bolts that fasten to the cases have there own issues. The issue is thermal growth. in this case, the fastener must be able to compensate for the cylinder growth when hot by stretching maintaining the same amount of compression as when cold and yet not exceed the material yield point of the fastener. This is why most of these fasteners have a waisted design. If the fastener is too stiff and does not stretch, something else will move and that's not usually so good. Ask me how I know this? | ||
| Phelan |
I do this for a living. Tootal is right. Torque plates are needed for Evo-up. The case studs and head bolts act as a vise holding the heads and cylinders in place. When proper torque is applied, which is 42 FT/LBS when using Cometic gaskets as we do, the heads and cylinders are squeezed and will flex under the torque. Heads are extremely solid compared to cylinders and flex not nearly as much. This is why we torque our torque plates down to 32 FT/LBS on cylinders, to mimic flex as much as possible. Keep in mind Evo-up torque plates have through holes at the top, not threads. Pre-Evo used torque plates with threads at both ends, to keep the clamping force of the honing jig off of the cylinders. | ||
| Stevel |
Phelan, I don't want to get into a pissing contest over this very simple thing, but you are just flat wrong. Now, do I use a fixture like a deck plate to machine cylinders? Yes, I do, but for secure holding on the machine, not for distortion reasons. Please measure this distortion you reference. I have done this many, many times and never saw these dimensional changes on clamped cylinders, the clamping force is simply far too light. Not only is the clamping force too light, but the force is applied to the casting not the sleeve. | ||
| Tootal |
The old cast iron shovelhead cylinders didn't distort much because they were solid cast iron. The Evo and Twin Cam have aluminum cylinders with metal bores that are thin. I can tell you from experience that if they are not bored/honed correctly you can tell when you take them apart after a few thousand miles. The area around the stud holes will tighten in the bore and you will see an obvious "window pane" in the bore. The area by the holes is shiny where the rings ride causing a square "window" effect. If they are properly honed in torque plates you will not see this. | ||
| Phelan |
I've seen over .001" difference in torqued vs not torqued, especially in Evo BT cylinders. Once I put them back in torque plates they straighten back up. Checked and verified with a bore gauge. I hone 15-20 cylinders a week. On our NRHS cylinders with thicker liners, it's not as much of a variance. But still there. Usually around .00025-.00050" between torqued vs not torqued. | ||
| Phelan |
Not every cylinder will show variance, but more do than not. | ||
| Phelan |
Mitutoyo bore gauge, Axtell torque plates.  | ||
| Tombo |
Some great expertise on this board and useful information. Still wondering if there is any meaningful pros or cons to steel vs. iron liners (friction, distortion, heat etc...). Planning a bump in compression and thought this would be the time to increase displacement. The 103 felt a bit anemic originally but a set of cams and good tuning woke it up, but still looking for a bit more. Plenty of options out there, but the new SE cylinders are the largest bolt-on option available, just not sure of the potential cons (other than the price). | ||
| Buelliedan |
I would not recommend that kit. When you bore the cylinders that big it causes the spigots to be paper thin. The CVO 110s come with cases that are bored .125" larger so they can use a thicker spigot. The biggest I recommend you go is 107" which is a 3.938" bore compared to that kits 4" bore. That is a huge difference (Message edited by buelliedan on September 08, 2015) |
