Mickey,

Although Wiesco owns JE, the Wiesco piston is NOT the same as the JE. What you will find is that the Wiesco piston that you claim to be using is cheaper in cost and is not anywhere near the quality of the JE or Ross piston -- at least that is what some of the horses mouths have said.

On the Cam issue, Web grinds custom cams for Trinity as well. Only thing is that Trinity does not mandate that Web only sell that grind to Trinity. They tell Web the results from a cam test and Web sells the cams to the general public. I nice idea for the public benefit.

On the three angle valve job, I suggest you revisit the issue. With three angles (the minimum that you can have to do a valve job, all you have is your valve face angle, the seat angle and then the throat and top angles on the seat. These angles tend to be sharp and upset (constrict) air flow. That is why performance engine builders will use additional angles (or a special shape carbide cutter) to round off, change or add additional valve and seat angles. This is in addition to a back cut and the margin shape of the valve. Yes, these small issues make major differences in air flow at low and high air speeds. That is probably why Trinity and Bikeworx tend to get some really good flow numbers from their heads. If you are just building the average Joe 686, 280cfm of flow can yield a maximum potential of about 70hp. So, because of other limitations of the 686 (carbs, chamber size, compression, mild cam, etc.) the 60 or so realized hp is well under the potential of a JOE port job. When you want to make over 70hp you must get the flow of the head way up over 280. That is tough considering the port volume issues.

As for the "bigger" engines, a stroked 660 is nice but it will not rev like the 84mm stroke. So, you must decide if you want more low-mid torque or what. Like the other comments here, you must tell your engine builder what type of riding you want as the engine must be configured for you.

 

raptor720,
I missed what CT racing did in dirt wheels. I am running their piston and exhaust. My questions is: why would we not support CT racing? Do they suck?
any input is appreciated.

 

Jay, look at your private email. I don't want to repost my objections to CT again here.

 

raptor720,
if you could. email me at slammed95impss@aol.com I would like to know your thoughts on CT. I checked my private email, and didn't see anyting
and, Does anyone know how to change my signature at the bottom of my posts? I typed 2 things wrong. (yep, total moron here) oh well.

 

I have talked with Steve Johnson from WISECO about this and he said "the next time this come's up let me know and I will take care of it". As far as 3 angle valve jobs go, each head is different and some heads require sharp edges to trip the air to get it around a corner or around a valve. You can talk all the technical talk you want but in general terms, a 3 angle valve job and the proper placement of the valve seat is important to make the head flow correctly. I asked you before to post flow bench testing and to show the people on here the difference between a 5 angle valve job and a 3 angle valve job and would also challenge you to show that the middle intake valve should be bigger. If someone at Trinity has done the R&D work and can show that the big valve flows more on the same head than the standard valve and that it makes that big of a difference then just simply show the people the proof. As I stated before, the amount, if it is different, will still not show up on the dyno.

 

OK,

Since I am in the middle of doing another big engine, I will take a new stock head, flow it, then take a modest port head with big valves and flow it. I think I still have data on a mild port head with stock valves. What I need to do is learn how to post the results on the site. Computers are not my ball of wax.

On the 3 vs. 5 angle( or more), I must totally disagree. The angle that the fuel/air comes off the seat and/or valve surface can easily cause a bottleneck in flow if the angle is not correct for the head design. Some heads might require sharp angles while others flow better with more of a radius. Some will flow better with a different shaped valve and others work best with the nail head design. This is part of the research that shops must do before they start building engines and charging customers for that "quality work." On the 660 motor, every little bit makes a major difference when you are looking for that last push. That is the difference between production and a custom engine. That is the difference between the 1-2 bikes at the end of the race.

On the piston issue, I would love to hear what Wiesco has to say. Wiseco, home of the production piston mill attempting to match the quality of a Ross or JE made to order piston shop. Get Steve Johnson from WISECO to post here. Have him explain what he means by his statement to you "the next time this come's up let me know and I will take care of it".

 

OK then I will pay to have it next day aired back and forth so you are only without your head for 2 days and I'll put it on my flow bench and post the results just to keep things on the "up and up" so it will be fair for everyone and not just one person's test. That sounds fair doesn't it?

 

Tell me about your bench. Mine is a Super Flow 600. The smaller machines just cannot show accurate results on a high flow head.

 

I have a flow bench and it isn't going to matter what kind it is. All we are trying to do is get a benchmark to show the difference between a 3 angle and a 5 angle valve job and the amount of air flow difference between a regular valve and a big valve head. Don't try to make it into something technical. It's real easy - it either flows more air or it doesn't. If I can't see it on my flow bench there isn't a difference.

 

Not getting technical but a bench that can't test at 28" of water cannot show the differences in such things as valve seat angles. For most work, a smaller bench is fine BUT I am after the Nth degree of VE from my motors. That is what gives me the extra 1-2 bike lengths when we hit the dirt. King Raptor is one example of a good running mild 686. His will run and run race all day 7 days a week and still drive on the trailer at the end of the day. Sure, like he said, there are faster machines but we have not seen them and cannot comment.

To date, the best we have seen from CT, Powroll, Sparks, Alba and a few other less known shops pales in comparason to the 686 standard issue from Trinity. Funny thing on that point, all parts on the Trinity 686 are available to anyone. Web cam 691-496 cam, JE 10.75:1 102mm piston, valve springs (optional), your choice of pipe, and air box mods. Now, we have seen many other people take the parts and come to the races thinking that they will be in the "ball park" but what happens is bikes like KingRaptor send them home crying. WHY?? Because PORTING and head work makes a major difference on a big cc single cylinder 5 valve motor.