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I'm interested in any comments from Bonneville 865 owners who have fitted Thunderbike cams as to what improvements they have noticed, and downsides, etc. I like the idea of not having to send off my existing cams rendering my pride and joy off the road for a period of time.
 

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Can\'t tell you never having used them. But until someone who has chimes in i can tell you what they\'re basically supposed to do. There have been cams used in some of the twins, specifically the 790s that were profiled for top end HP at the cost of low end torque. Then there were cams used in some of the other models that were profiled for torque at the cost of HP at the top. So it was a tradeoff. The Tbike cams supposedly are developed to give you the best of both. I would assume they are also not going to meet emissions standards some places. But if they do what they are supposed to that would be nice. Kinda expensive tho when you consider the triumph BB kit for the new Tbird costs the same and comes not only with the piston kit but also cams ! But anyways, whether they do this or not they do what they are supposed to, you will have to wait for a reply from someone who has them. But in any case thats what they are supposed to do. ....HP of the 790 cams and torque of the 865 cams. By the way, are you sure they make them for the 865 bonnie? I thought they only made them for the cruisers which are 270 degree engines and therefore those cams wouldnt work for you. So make sure before you buy ! I never saw them for the 360 degree engines, but then again i haven\'t looked for probably a year.
 

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Are they still asking potential customers to buy their cams without providing any specs for them? I'm not an engine builder, so it's of little importance to me, but there's lots of folks on this forum who build up their Bonnie engines. I find it incredible if they are still selling without providing tech info. Nahhhh ... they couldn't be!

Of course, someone who has already purchased their cams could undoubtedly measure lift through 360 degrees, and compare it with 790 or 865 stockers.

Bob
 

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I would not spend my money on them .TB came out with there cam because when triumph came out with the 865 motor they put milder cams in it so they could make epa reg.They use to say it was for the 865 motor not the 790 because it was no better then the 790 cams .by the way most that have but 790 cams in the 865 gained torque most every where in the rpm range.The tpusa cam is better then the old 790 cam hands down.If you are going to spend money on cams thats the way to go.
 

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I'm interested in any comments from Bonneville 865 owners who have fitted Thunderbike cams as to what improvements they have noticed, and downsides, etc. I like the idea of not having to send off my existing cams rendering my pride and joy off the road for a period of time.
I have a set of Thunderbike cams for my 865 T100 but I have not fitted them yet so I can't give you any feedback on actual performance improvements. What I can tell you is that they are a very high quality product. Machined from billet they are stronger than the OEM cast camshafts and far superior quality wise to a welded up and reground OEM camshaft that most other sellers offer.

The cost was only AU$200 more than it would have cost to purchase a set of reground cams from the US and the Thunderbike cams have the advantage of not requiring a core exchange thus you don't have your bike of the road waiting for your cams to be shipped to and from. This was a big selling point to me because I am in Australia and additionally I wanted to retain my original cams so that I could return the bike to stock should I so desire in the future.

Performance wise I expect them to be only slightly better than early 790 cams but this suits me as I am not going to be doing any other internal modifications to the engine such as a big bore kit, high compression pistons or head work and I will be retaining the stock carbs so a more radical cam grind would offer little advantage in my case.

I am waiting for the warranty on my bike to expire and for other components to arrive before I proceed with fitting the Thunderbike cams but I will give a full report, hopefully including before and after dyno runs, once the mods are completed and the bike is properly tuned.
 

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Are they still asking potential customers to buy their cams without providing any specs for them? I'm not an engine builder, so it's of little importance to me, but there's lots of folks on this forum who build up their Bonnie engines. I find it incredible if they are still selling without providing tech info. Nahhhh ... they couldn't be!

Of course, someone who has already purchased their cams could undoubtedly measure lift through 360 degrees, and compare it with 790 or 865 stockers.

Bob
This is a contentious point Bob and has been debated on here before. Specs can be provided ad nauseum and at the end of the day, they don't necessary correlate to improved performance. More lift, duration or overlap doesn't necessarily mean more or less torque or horsepower. If you don't have a dyno comparison, you almost have to go on anecdotal accounts here from those that you respect.
Cam spec's btw are arrived at by trial and error, dyno and street testing. The average performance enthusiast on here has no chance of interpreting performance based upon specs. Many cam suppliers understand this and why they are hesitant to even provide spec's because they can be used against them in cam selection and of course loss of proprietary advantage. Those that have gone the 813 cams rave about them and the cams I would go with.
George
 

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The difficulty we face as consumers of performance parts is that none, or very few, of us can afford to actually try competing products ourselves on our bikes. You can argue about Thunderbike vs. TPUSA cams, Hagons vs. Ikon, gel seat vs. Corbin all day long, but unless someone does a test of each on comparable bikes eliminating other variables, it's just a fun debate. There's so many other things on a bike engine which would affect overall performance increases in each application. The question you should ask yourself is what is my goal by doing an engine mod? What am I trying to accommplish? That's what Carlos at TPUSA asked me before I started upgrading my engine, and it was a darn good question.
I bought the 813's, not because of the specs., but because I trusted the people who had them and wrote about the cams on bike forums. Those cams do a heck of a job and I've very satisfied with 'em.
Heck, back in my old hot rodding days, we'd buy parts based on what we read in magazines. Mickey Thompson runs Crane cams, so they must be good. Then we'd talk with our buddies, race around and compare. That's kind of the function of these internet forums when we jaw about parts, only on a much bigger scale. Just like back then you'll get your brainiacks who crunch the numbers, and you'll get real life mechanics who know the practical stuff. I personally prefer the opinion of the mechanics.
 

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I don't think I've seen any reports of thunderbike cams, I have heard a few folks talk about them.

There was this thread:

http://www.triumphrat.net/twins-technical-talk/98616-thunderbike-cams.html

But I have not seen a direct "this bike before and after thunderbike cams were fitted" comparison. Often when fitting performance parts, other parts are fitted at the same time, so it is difficult to tell what did what.

When looking at reviews of parts I basically look at as many reviews as I can, try and glean a little about what each person wanted in their case, and build up a picture of how the parts worked overall.

Unfortunately I just haven't seen any reviews of thunderbike cams, so i have no idea whether they are any good or not - especially as I haven't tried them. Given that I have seen lots of reviews of other cams, I will go that route when the time comes.

If someone has used the thuderbike cams it would be great to hear about, but we may just have to wait for Aussie-T100s review for that.

In terms of cost and waiting and so on, that's up to each individual to decide what they want to do I guess. If I were getting into serious motor builds (hope to!) I think I would try and get a spare motor so that I could keep the bike going while putzing about - to me that cost on top of what you can end up spending would not be out of order. It all depends what you want to do I guess. I dunno. Think I'll take the day off work and ride my bike around and muse on it.
 

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TB cams

I have the Thunderbike cams in my 05 speedmaster and they are a huge improvement over the stock cams. Lots of low end power. That said, the stock cams in the 865- 270 motors are extremely mild.

Probably doesn't matter so much for the 865-360 motor in the Bonnevilles. As Dazco mentioned, these cams were for the 270 crank motors.

As to sweatmachines claim, I measured up the TB cams before installing them to compare with the 865 cams, if someone here has a set of 790 cams it would be interesting to compare them as well.
 

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I don't think I've seen any reports of thunderbike cams, I have heard a few folks talk about them.

There was this thread:

http://www.triumphrat.net/twins-technical-talk/98616-thunderbike-cams.html
There's been quite a lot of discussion about the Thunderbike cams on this forum - here's a few more for you:-

http://www.triumphrat.net/twins-technical-talk/77056-stage-1-cam.html

http://www.triumphrat.net/twins-technical-talk/108453-thruxton-with-cams.html

http://www.triumphrat.net/twins-technical-talk/43684-thunderbike-com-nz.html

If someone has used the thuderbike cams it would be great to hear about,
Well Thruxtonboy seemed to do alright with them - admittedly along with a lot of other mods but you can't argue with the end result:-

http://www.triumphrat.net/twins-technical-talk/76374-more-powerful-thruxton.html

but we may just have to wait for Aussie-T100s review for that.
I have yet to sus out the local dyno operators but IF I can find a good one that doesn't charge an arm and a leg I may do three runs, one stock, one with airbox, exhaust & ignitor mods and a final run with the cams added so that their individual input is quantified. First step is to get the A/F gauge fitted so that I can accurately tune the bike at each stage.
 

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I see that they've 790 cams in development now.
 

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mag 10 makes a good point the 270-865 cams are very mild cams prob the worst cams triumph made .There for ether the thunder bike or the 790-270 cams would make good gains.We have seen ventura prove the 790-270 intake cam pick up hp on the test he did.
Some of the flat track guys did testing compareing the 790-270 cams and the thinder bike cams they said thunderbike cams made no more hp.I have the 813 cams and know the specs the only thing i will tell you is the 813 cams are as much better then the 790 cams as the 790 cams are better then the 865 cams.sweatmachine is running my old 03 790 cams they are not the best of the 790 cams but he gain hp over the 865 cams he was useing.Iput the 813 cams in when I took those out.The 813 cams pull much harder from 3500 on and will pull hard to near 9000 rpms.The 790 cams are done much above 8000rpm.
The 865 cams go flat some where around 6500 to 7500 rpms .These motors love more cam .
The max torque on all of them is in the 3500 to 5500 rpm range .The better the cam the higher rpm it will hang on to more of that torque,thats how you gain hp on these motors.
If you dont want to do with out your bike pick up a used set of cams and send them off.If power is what your after you wont beat tpusa cams.
 

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I have the 813 cams and know the specs the only thing i will tell you is the 813 cams are as much better then the 790 cams as the 790 cams are better then the 865 cams.
Aww, come on Mike tell us the 813 specs - nobody seemed to mind when the Thunderbike cam specs were posted here:-

http://www.triumphrat.net/twins-technical-talk/96864-ok-im-now-addicted-to-hp-which-carb-setup.html#post1137173

What's good for the goose is good for the gander. ;)

If you dont want to do with out your bike pick up a used set of cams and send them off.
But then you would have spent as much as you would have buying the Thunderbike cams and the Thunderbike cams are billet cams not welded / reground cast OEM's. :D

The Thunderbike cams are US$857 delivered to your door, TPUSA cams are US$695 plus freight both ways (core exchange required). That's the comparision in black and white from a dollars point of view for US residents. Don't start me on exchange rates, overseas freight costs and waiting times for non US residents.

If power is what your after you wont beat tpusa cams.
That's a blanket statement, I have no doubt the 813's are a more radical grind than the Thunderbike cams but that would make them more suitable to an engine with more radical mods too wouldn't it? The 813's would probably only make marginally more horses than the Thunderbike cams in a comparatively stock engine for example and may even lose out on torque / streetability in that case. It's a matter of matching your components.

If I was going full hog with BB kit, headwork, 42's and D&D 2 into 1's I may have chosen the 813's but with only ARK, slipon's and ignitor mod planned the TB cams are probably a better match. Of course TPUSA has lesser grinds than the 813's that would probably be a good match to my mods as well but then the billet / reground and core exchange argument wins for the Thunderbike cams in that case in my opinion, especially if you are a non US resident.

In any event it's good that we have a choice of excellent products.
 

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But then you would have spent as much as you would have buying the Thunderbike cams and the Thunderbike cams are billet cams not welded / reground cast OEM's. :D
I think the OEM cams are forged, not cast, in which case they're stronger and harder than the billet. Also, everyone knows the actual weld is stronger than the material it's welded onto. I don't think the fact that it's welded is a negative thing, provided it doesn't cause any distortion in the rest of the cam, and doesn't anneal it.
 

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the 813 cams are not wild cams they work fine in a standard bore motor with normal mods the reground cams are just as hard as stock cams stock cams will last as long as the rest of the motor so tb cams are no better that way ether.In your case if you can find some used 790 cams you will be about as good off as buying the TB cams .Thats about all they are.One thing you need to understand bore size has very little to do with what the cams up to and includeing the 813 gain or loose as far as power gain (just in the cams alone) the heads on these bikes need more cam then epa will let triumph put in them.I think if we knew the true story behind the 865 motor you would find out they only went from the 790 to the 865 to keep enough power with the poor 865 cams that would pass epa test.I would even bet you bone stock bike to bike a 01 790 bonnie will out run most all of the 865 bikes.
When you are looking to go inside these motors to get more hp you better get your money out and going cheaper dont all ways pay in the long run.you will want more hp before long then you will want head work big bore kit carbs better pipes and after all that you will say dang wish i had got the good cams to start with.So deside where you want to go with mods before you start them and you will save money.Or just do the airbox kit , pipes ,and some good carbs and leave it at that.
 

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I think the OEM cams are forged, not cast, in which case they're stronger and harder than the billet. Also, everyone knows the actual weld is stronger than the material it's welded onto. I don't think the fact that it's welded is a negative thing, provided it doesn't cause any distortion in the rest of the cam, and doesn't anneal it.
Well I'm not a metallurgist so I'm not going to dispute your opinion but to my untrained eye there does seem to be sand casting marks on the standard cams and I've seem others refer to them as cast cams.



Wouldn't you say they were casting marks on the centre section of those cams?

Reground cams have been in use for years and I have used them myself in car engines many times without problems but if you ask an experienced engine builder to chose between a billet cam and a reground OEM cam, given the same profiles, which do you think he will chose?
 

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Cast and forged often appear the same - they are both a molding process; casting is only gravity fed or injected, while forgings are highly compress and very dense.

Looks can be deceiving, a knowledgeable engine builder would evaluate more than billet vs welded forging, because he knows that not all welders are equal and not all bar stock is the same.
 

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the 813 cams are not wild cams they work fine in a standard bore motor with normal mods the reground cams are just as hard as stock cams stock cams will last as long as the rest of the motor so tb cams are no better that way ether.In your case if you can find some used 790 cams you will be about as good off as buying the TB cams .Thats about all they are.One thing you need to understand bore size has very little to do with what the cams up to and includeing the 813 gain or loose as far as power gain (just in the cams alone) the heads on these bikes need more cam then epa will let triumph put in them.I think if we knew the true story behind the 865 motor you would find out they only went from the 790 to the 865 to keep enough power with the poor 865 cams that would pass epa test.I would even bet you bone stock bike to bike a 01 790 bonnie will out run most all of the 865 bikes.
When you are looking to go inside these motors to get more hp you better get your money out and going cheaper dont all ways pay in the long run.you will want more hp before long then you will want head work big bore kit carbs better pipes and after all that you will say dang wish i had got the good cams to start with.So deside where you want to go with mods before you start them and you will save money.Or just do the airbox kit , pipes ,and some good carbs and leave it at that.
Well Mike you are a great one for saying "you can't talk the talk unless you've walked the walk" and you've been playing with these engines for some time now so I respect your opinion. By comparison I am a beginner when it comes to these particular engines so all I can do is look at what is being achieved by others, analyze it, make my own judgements based on my experience with other engines and formulate my own opinion from there.

Thruxtonboy's Art Nolen modified 904 Thruxton with Thunderbike cams managed to break 90RWHP (actually the latest is 115DIN HP if you look at his youtube page) and I note by comparison that your similarly modified 904 with 813 cams is yet to break 85RWHP.

http://www.triumphrat.net/twins-technical-talk/76374-more-powerful-thruxton-6.html#post1003265

http://www.triumphrat.net/twins-technical-talk/109771-904tpusa-with-813-cams.html#post1265456

Considering that you have 11.5 to 1 comp as opposed to Thruxtonboys 10.5 to 1 and the "superior" 813 cams as well as 42mm carbs as opposed to Thruxtonboys 39's and the fantastic D&D 2 into 1's I expect you will soon surpass Art Nolens efforts. :D

I note that even Carlos, the "man behind" the 813's, was very impressed with Thruxtonboy's / Art Nolen's efforts in Thruxtonboys thread:-

http://www.triumphrat.net/twins-technical-talk/76374-more-powerful-thruxton.html

I know nothing - just an interested and open minded observer.
 

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Cast and forged often appear the same - they are both a molding process; casting is only gravity fed or injected, while forgings are highly compress and very dense.
So other than your opinion do we have any hard evidence that Bonnie OEM cams are forged not cast?

I sincerely hope you are correct but I would like to see hard evidence.
 
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