 My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 175
Adjunct
|
OP
Adjunct
Joined: Aug 2006
Posts: 175 |
After reading many threads on this forum I've found out 790 cams are better than 865... A month ago I decided to take the plunge and upgrade for several reasons...
1 - For 39cc I couldn't see the point of a B/B kit when there's nothing wrong with my pistons and bores...
2 - B/B kit, Freak and carbs arn't cheap either...
3 - Might as well get it breathing more freely...
4 - Nobody else has done it and written about it...
5 - Spend my money locally...
6 - Hopefully an unbiased opinion...
I never rode my bikewith the standard pipes, T/B longs fitted apon delivery in Dec 04... 1 week later at 1st service they put the standards back on for dyno runs...
Dec 04 - 52HP - standard pipes
56HP - T/B pipes
May 07 - 58HP - 26000km T/B pipes, snork removed, everything else stock
Jun 07 - 79HP - T/B cams, pipes, flowed head,air box mods, AI removed, 135 mains, stronger clutch springs
sorry, doin this in 2 parts
05 SM Neon Blue/Black. Thunder Bike Cams & Pipes & Flowed Head. AI&Snork removed, Airbox Mods, 135mains, 42/17T, 140x80x17" TBS Front Wheel
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 175
Adjunct
|
|
OP
Adjunct
Joined: Aug 2006
Posts: 175 |
Dyno shows flatspot midrange, might try another dyno shop in town which has the air/fuel ratio... Dynojet kit might be in order, still stock air filter...
Any suggestions regarding mains, pilots, needles etc welcome...
It cetainly is a whole new beast to ride, and are liking it a lot, stronger top end for sure...
Slightly harder to start and takes longer to warm up and idle, adjustments to carbs no doubt...
I know some are gonna ask so
Cost - lots...
Off premises work at 2 machine shops 900
Parts, etc 1600
Labour 500
-----
$3000 NZD
Think I spent enough this year...
Dyno charts in my gallery, I don't no how to put them here...
05 SM Neon Blue/Black. Thunder Bike Cams & Pipes & Flowed Head. AI&Snork removed, Airbox Mods, 135mains, 42/17T, 140x80x17" TBS Front Wheel
|
|
|
 Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 1,179
Learned Hand
|
|
Learned Hand
Joined: Jan 2005
Posts: 1,179 |
A 4HP increase from stock pipes to T/B pipes? So much for T/B's "28% increase" claims..... I have a set by the way and I'm happy with them. I just don't (didn't) believe the hype. I wonder what the HP gains were with "air box mods, AI removed, 135 mains", prior to the head work and cams? Exactly where were you standing when the big bag of money fell on you?  Great write-up and thanks for the info! Regards, Tom
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 9,223
Big Bore
|
|
Big Bore
Joined: Jan 2005
Posts: 9,223 |
Here ya go Mike. btw, you might want to try the TBS needles for that flat spot. Horsepower:  Torue: 
"Never underestimate the power of human stupidity" - Robert Heinlein
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 2,664
Loquacious
|
|
Loquacious
Joined: Jan 2005
Posts: 2,664 |
Well WildMike, Even with the flat spot, that's a mighty fine looking dyno. You done real good.  I'm jealous - with my little 790 engine and old motorcicle.
Ride Safe,
Dennis
Triumph, it's how I live and what I ride.
|
|
|
Re: My Thunder Bike Cams
|
Joined: Mar 2005
Posts: 185
Adjunct
|
|
Adjunct
Joined: Mar 2005
Posts: 185 |
It doesn't look like to reap much benefit until you're up past ~5200 RPM, hp-wise. I see 5-10% increase in torque @ 3000-5000 until the big leap at about the same spot as the HP.
For everyday riding, how much more power do you "feel?" The only time I get above 5K RPM is when I really need to get on it - very rare - or on this one straight/safe stretch near my house when I'm just playing around.
From the points in your initial post, I somewhat understand the motivation behind the mods, so I'm just trying to justify this mod for my bike (vs. the big bore / freak route).
|
|
|
Re: My Thunder Bike Cams
|
Joined: Apr 2007
Posts: 404
Adjunct
|
|
Adjunct
Joined: Apr 2007
Posts: 404 |
I ended up with a 42 pilot jet. The chap seemed to think it would start up better and have a shorter warm up period. Needle 1.5 up. Main 140 (54g). Screws 1.5 turns. Mine runs the K&Ns ( freak ) ai out. Custom Chamber pipes.
|
|
|
 Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 175
Adjunct
|
|
OP
Adjunct
Joined: Aug 2006
Posts: 175 |
Just had my first decent ride, 200k, the weather turned it on with a break, clear an cool, mid winter here. 51 bike after solstice run... Awsome to have an extra 20hp to play with, no problem power spots at any rpm, certainly likes to rev now, I'm luvin it... Got my soldering iron set up, time to hide wiring in the bars.. 
05 SM Neon Blue/Black. Thunder Bike Cams & Pipes & Flowed Head. AI&Snork removed, Airbox Mods, 135mains, 42/17T, 140x80x17" TBS Front Wheel
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 321
Adjunct
|
|
Adjunct
Joined: Aug 2006
Posts: 321 |
stock clutch? no slipping?
There is no greater thrill than being shot at with no consequence. -Churchill
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 175
Adjunct
|
|
OP
Adjunct
Joined: Aug 2006
Posts: 175 |
Upgraded clutch springs is included in their performance package...
05 SM Neon Blue/Black. Thunder Bike Cams & Pipes & Flowed Head. AI&Snork removed, Airbox Mods, 135mains, 42/17T, 140x80x17" TBS Front Wheel
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 321
Adjunct
|
|
Adjunct
Joined: Aug 2006
Posts: 321 |
so you really gained 20hp just from cams? man...
There is no greater thrill than being shot at with no consequence. -Churchill
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jul 2005
Posts: 284
Adjunct
|
|
Adjunct
Joined: Jul 2005
Posts: 284 |
so are the cams worth it....
Duck
Road Rabble MHi
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 153
Adjunct
|
|
Adjunct
Joined: Aug 2006
Posts: 153 |
He didnt gain 20 horses from cams alone, he gained it from cams, head work..( does this include port/polish?...oversized valves...?..)
Also, was a upgraded limiter installed?
EDIT: I see your running a 865 motor, assuming it is a 270* motor you wont have a upgraded limiter..( to my knowledge noone is doing this aside from jorgen maybe )..are you running a speedmaster or a america? What year?
It's a shame we couldnt see specific result's from a 3rd party dyno that would reflect the result's of individual mod's alone ie: cam's, then head flowed, etc....
The number's are good nontheless, no disputing that. They are comparible to my bike. Can't wait to get headwork done to mine.
Last edited by SCCTrim; 06/26/2007 10:04 AM.
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 321
Adjunct
|
|
Adjunct
Joined: Aug 2006
Posts: 321 |
Trim, I think there are minimal gains from head-flowing and bigger valves, especially with stock cams, but maybe the aftermarket cams really enhance the benefits and work well together.
I may start looking for a set of 790 cams(after the mikunis of course)...
There is no greater thrill than being shot at with no consequence. -Churchill
|
|
|
Re: My Thunder Bike Cams
|
Joined: Apr 2005
Posts: 100
Adjunct
|
|
Adjunct
Joined: Apr 2005
Posts: 100 |
 These here are the dyno charts for the Speedmaster and America 865cc models fitted with both standard and Thunderbike mufflers,as displayed on our website.  And these here are the dyno charts for 3 types of mufflers tested on the 790cc models as displayed on our website. If you care to check the actual information on the page - http://tinyurl.com/2bnasw - you will find all the information is there. The 'hype' as you describe it was no doubt referring to the increase in peak power obtainable on the inital 790cc models, at NO time have we ever claimed the same results from the 865cc versions. Our entire camshaft manufacturing project was based on the restricted nature of the 865cc models breathing abilities and whereas the 790cc was uncorked with a bit of external modifications the 865cc required internal fettling. The 'hype' as you call it is/was 100% true and accurate - you are simply applying the results obtained from the earier version to a model that they were never claimed for. Glad to hear that you are happy with the work Mike, we appreciate the informative unbiased thread  Quote:
A 4HP increase from stock pipes to T/B pipes? So much for T/B's "28% increase" claims..... I have a set by the way and I'm happy with them. I just don't (didn't) believe the hype.
I wonder what the HP gains were with "air box mods, AI removed, 135 mains", prior to the head work and cams?
Exactly where were you standing when the big bag of money fell on you?
Great write-up and thanks for the info!
Regards,
Tom
|
|
|
Re: My Thunder Bike Cams
|
Joined: Apr 2007
Posts: 404
Adjunct
|
|
Adjunct
Joined: Apr 2007
Posts: 404 |
Um.. er Tom are you there? Now is the time man. 
|
|
|
Re: My Thunder Bike Cams
|
Joined: Aug 2006
Posts: 153
Adjunct
|
|
Adjunct
Joined: Aug 2006
Posts: 153 |
Quote:
Trim, I think there are minimal gains from head-flowing and bigger valves, especially with stock cams, but maybe the aftermarket cams really enhance the benefits and work well together.
I may start looking for a set of 790 cams(after the mikunis of course)...
Thats very possible, it is afterall the combined end result of mods working together that produce results as opposed to any one piece of the puzzle. I'm looking at buying a new head, having the chamber reshaped, oversized valves, and some flow work done by our mutual aquaintence at rat.net...he's close to me and has offered to hook me up with some headwork.
In response to the above posted dyno sheets displaying a 18hp gain from stock to thunderbike mufflers...I don't buy it. Understand I intend no slander, I just dont buy that kinda gain from pipes. If theres something I'm missing and other mods are present I apoligize.
Ever sent your product's out for 3rd party independant testing? Those result's would be more convincing...
|
|
|
Re: My Thunder Bike Cams
|
Joined: May 2005
Posts: 711
Adjunct
|
|
Adjunct
Joined: May 2005
Posts: 711 |
So please let me make sure I understand... the 790 cannot benefit from improved/upgraded cams, as the current cams are... "very good" if not "perfect"?
I.e., anybody going to make some hotter cams for the 790 engine?
--Jaeger
NEUTIQUAM ERRO
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 3,753
Loquacious
|
|
Loquacious
Joined: Jan 2005
Posts: 3,753 |
i have heard of rumors of this possibly happening, but i am not sure if it will actually happen
Frank
(Former)05 BA tbike pipes, ai removed, Freak, mikuni hsr 42's, 904, ported/polished head, 1mm oversized valves
NOW-2010 silver and black tbird
|
|
|
Re: My Thunder Bike Cams
|
Joined: Mar 2006
Posts: 1,540
Learned Hand
|
|
Learned Hand
Joined: Mar 2006
Posts: 1,540 |
I would venture a guess that since the 790 requires it's own grind and the 790 isn't produced anymore. And the 865 is going to be produced for all bikes now. That more effort will be given to the 865.
|
|
|
Re: My Thunder Bike Cams
|
Joined: Apr 2005
Posts: 100
Adjunct
|
|
Adjunct
Joined: Apr 2005
Posts: 100 |
Hi, I understand your comment and I`m pleased that you have no slanderous intention I appreciate that. These forum pages were quite literally my evenings work back when we invented the 790cc pipes and it took over a year before they really got rolling on the other side of the world from us here in New Zealand. Every single question or doubt that you have will (I promise!) have already been discussed and verified here in the vaults of this forum I`m sure from the many happy owners here. We couldn`t believe the results ourselves here as experienced techs, riders and engineers so I understand your lack of belief - its true though however your beliefs placed on the subject. Cheers. Quote:
Quote:
Trim, I think there are minimal gains from head-flowing and bigger valves, especially with stock cams, but maybe the aftermarket cams really enhance the benefits and work well together.
I may start looking for a set of 790 cams(after the mikunis of course)...
Thats very possible, it is afterall the combined end result of mods working together that produce results as opposed to any one piece of the puzzle. I'm looking at buying a new head, having the chamber reshaped, oversized valves, and some flow work done by our mutual aquaintence at rat.net...he's close to me and has offered to hook me up with some headwork.
In response to the above posted dyno sheets displaying a 18hp gain from stock to thunderbike mufflers...I don't buy it. Understand I intend no slander, I just dont buy that kinda gain from pipes. If theres something I'm missing and other mods are present I apoligize.
Ever sent your product's out for 3rd party independant testing? Those result's would be more convincing...
|
|
|
Re: My Thunder Bike Cams
|
Joined: Apr 2005
Posts: 100
Adjunct
|
|
Adjunct
Joined: Apr 2005
Posts: 100 |
Hi, My point was that we have tried and found the level of improvement obtainable less than impressive ie. nobody would buy them, disappointing but true. Cheers. Quote:
So please let me make sure I understand... the 790 cannot benefit from improved/upgraded cams, as the current cams are... "very good" if not "perfect"?
I.e., anybody going to make some hotter cams for the 790 engine?
--Jaeger
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 6,308 Likes: 4
Worn Saddle
|
|
Worn Saddle
Joined: Jan 2005
Posts: 6,308 Likes: 4 |
Quote:
So please let me make sure I understand... the 790 cannot benefit from improved/upgraded cams, as the current cams are... "very good" if not "perfect"?
I.e., anybody going to make some hotter cams for the 790 engine?
--Jaeger
Jaeger,
I have a set of custom ground Megacycle cams in my 904cc 270º motor. They are made specifically for a 904 Speedmaster and have what MC calls their "Medium Street Grind". I purchased them used from a third party through one of our vendors here and did not have to send mine in to be reground which you normally would do. Megacycle cuts the lobes off, welds new material onto the cams and then regrinds for various valve timing and throw. That is the difference between their street grind, stock, and high performance grind. They are all ground with totally different specs. I posted dyno results somewhere but cannot come up with the prints since I just moved. When I find them (I have about 10 pages of dyno results so far) I will post them all on my site with all the info for each.
Anyway, the MC cams gave me about 2 hp gain in power, but dropped the torque about 2 ft/lbs at the same time. They make the bike really wind up quicker, but overall, I have to say that for the cost of the cams, not really worth the big bucks ($6-700 at MC, but I paid less for mine).
There has also been a ton of discussion over at RAT.net as well as the Delphi 2001+ modified bonnie forum (don't know if there is an issue with that site or if I was just downright banned, I cannot get in for some time now) in regard to cams and using stock 790 cams in 865 motors and using two intake cams in the 790s as well. But that is more for racing and using the higher end of the revs, such as the flattrackers do. I have my original cams sitting in a box in the garage and it seems they are now valuable if the 865 will be the only motor made from now on.
Ok, enough rambling for now.
A word to the wise is not necessary. It is the stupid ones who need the advice.
Pat
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 8,639 Likes: 3
Old Hand
|
|
Old Hand
Joined: Jan 2005
Posts: 8,639 Likes: 3 |
Add line 1-A, with the stock government designed cams, the extra 39 CC's won't do anything useful anyway.  You are on the right track. It doesn't matter how big the engine is if it can't breath, cubic inches of displacement only count if you are getting a large enough volume of air in and out of the engine.
Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 1,179
Learned Hand
|
|
Learned Hand
Joined: Jan 2005
Posts: 1,179 |
Looks like I should revisit older posts more often. It appears I confused the 865 and 790 HP claims. I apologize to the people at Thunderbike. Quote:
Um.. er Tom are you there? Now is the time man.
I assume this was directed toward me. I've never hid from anyone.
Regards,
Tom
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 8,639 Likes: 3
Old Hand
|
|
Old Hand
Joined: Jan 2005
Posts: 8,639 Likes: 3 |
Quote:
So please let me make sure I understand... the 790 cannot benefit from improved/upgraded cams, as the current cams are... "very good" if not "perfect"?
I don't know that the 790 cams are perfect, but they are much better than the 865. In fact, there have been reports of substantial power gains from installing 790 cams in the 865 engine. Since the stock cams are really good for normal street riding, it would be hard to improve on them except by going to a custom cam grinder and getting a special profile specifically designed for your purpose, drag racing, road racing, dirt track or whatever.
Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jul 2006
Posts: 1,337
Learned Hand
|
|
Learned Hand
Joined: Jul 2006
Posts: 1,337 |
Anyone have any knowledge or experience with the British custom cams? They advertise two cam profiles. The street II grind require under bucket shims.
One thing I have not seen discussed here is compression bleed off from overlap on the cams. Usually when you go up in cam lift and duration, you get some compression bleed off.
2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 8,639 Likes: 3
Old Hand
|
|
Old Hand
Joined: Jan 2005
Posts: 8,639 Likes: 3 |
It's been mentioned in a backhanded sort of way during big bore kit discussions. Compression pressure bleeds off at lower engine speeds, allowing higher compression ratios with lower octane fuel. At high engine speeds where the cams are designed to give optimum power, the effective compression is higher that the actual ratio because the cams are packing more air into the cylinder. This works well because the engine is turning fast enough that the ignition lights off the mixture before it heats up enough to detonate.
Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jul 2006
Posts: 1,337
Learned Hand
|
|
Learned Hand
Joined: Jul 2006
Posts: 1,337 |
2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...
|
|
|
Re: My Thunder Bike Cams
|
Joined: Nov 2005
Posts: 57
Member
|
|
Member
Joined: Nov 2005
Posts: 57 |
OK, NOW YOU HAVE BOUGHT AND INSTALLED THUNBERBIKE CAMS..............
WHAT ARE THE ****** SPECS FOR THESE CAMS ????????????????????
|
|
|
Re: My Thunder Bike Cams
|
Joined: Mar 2005
Posts: 57
Member
|
|
Member
Joined: Mar 2005
Posts: 57 |
|
|
|
Re: My Thunder Bike Cams
|
Joined: Nov 2005
Posts: 57
Member
|
|
Member
Joined: Nov 2005
Posts: 57 |
OK, NOW YOU HAVE BOUGHT AND INSTALLED THUNBERBIKE CAMS..............
WHAT ARE THE ****** SPECS FOR THESE CAMS ????????????????????
|
|
|
Re: My Thunder Bike Cams
|
Joined: Nov 2005
Posts: 57
Member
|
|
Member
Joined: Nov 2005
Posts: 57 |
Confidential. Pigs Arse!!!!! If Thunderbike can use this forum to back door advertise their products then the cam specs should be also displayed!!!!
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 9,223
Big Bore
|
|
Big Bore
Joined: Jan 2005
Posts: 9,223 |
To clarify, Thunderbike is actively attempting to support this site through advertisements. WE are having issues getting to Robert...
"Never underestimate the power of human stupidity" - Robert Heinlein
|
|
|
 Re: My Thunder Bike Cams
|
Joined: Mar 2005
Posts: 57
Member
|
|
Member
Joined: Mar 2005
Posts: 57 |
Well, anyone's of course entitled to have an opionion about that.
|
|
|
Re: My Thunder Bike Cams
|
Joined: Mar 2005
Posts: 185
Adjunct
|
|
Adjunct
Joined: Mar 2005
Posts: 185 |
sorry, but I have to ask this again:
so...how much more do you "feel" these gains when riding at motor speeds typical of a cruiser?
w/ an 18T sprocket i'm typically cruising @ ~4K RPM's. it's not often i'm up over 5K, and very rarely over 6K. my limitted knowledge of how a motor works suggests that the nature of a cam upgrade, as confirmed by all of the dynos i've seen for the TB cams, will only provide marked gains at higher RPM's.
if i had a money tree it would be a no-brainer, but i'm sincerely trying to decide between this upgrade and the big bore kit (790/America), and it just seems to me that the latter will produce more usable power.
|
|
|
Re: My Thunder Bike Cams
|
Joined: Nov 2006
Posts: 1,302
Learned Hand
|
|
Learned Hand
Joined: Nov 2006
Posts: 1,302 |
Toofless, as graham said,if you don't use the upper half of your tacho they aren't for you. I know for some reason I am not that comfotable running above five k consistantly, just makes me nervous. the big bore will help with the lower end for sure.
mke
2006 neon blue speedmaster
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jul 2006
Posts: 1,337
Learned Hand
|
|
Learned Hand
Joined: Jul 2006
Posts: 1,337 |
Quote:
...if i had a money tree it would be a no-brainer, but i'm sincerely trying to decide between this upgrade and the big bore kit (790/America), and it just seems to me that the latter will produce more usable power.
If you have a 790 motor, the cams upgrade will be minimal, where as the 904BB will be substantial.
From all the dyno sheets I've read, it seems that:
on a 790, the 904BB will get you close to 75-80 with a FREAK type kit and good pipes.
on a 865, cams and carbs will get you 75-80 with a FREAK type kit and good pipes.
I wish someone made a 10.5:1 drop in piston for the 865
2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jan 2005
Posts: 3,753
Loquacious
|
|
Loquacious
Joined: Jan 2005
Posts: 3,753 |
getting that kind of power out of the 865 also involves headwork for upping compression
Frank
(Former)05 BA tbike pipes, ai removed, Freak, mikuni hsr 42's, 904, ported/polished head, 1mm oversized valves
NOW-2010 silver and black tbird
|
|
|
Re: My Thunder Bike Cams
|
Joined: Jul 2006
Posts: 1,337
Learned Hand
|
|
Learned Hand
Joined: Jul 2006
Posts: 1,337 |
Yes, you are absolutely correct, Frank (of coarse), head work on both, really. I've read and been told by those who know that know that there is some compression bleed off with the cams, too.
2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...
|
|
|
|
|
