WHY ARE OUR CAMSHAFTS BETTER?*


GTT, US & UK Ford kent based Triumph Camshafts compared.
*OURS are based on a full flow bench evaluation of what made/makes the Triumph heads work.
(Designing a range of better cams for these engines has always been an ambition as a project since the 1980s).

We worked with those who developed the original works camshafts. This is not possible any more.
(As most of those people are dead)
Our cams therefore, resemble the proper Triumph cams very strongly, giving stable idle & a massive wide power band with no need for stupid strength valve springs.
(In fact most of the time we use SINGLE linear rate valve springs.)

We get exceptional results from the original OEM cams because we understand the vital relationship between the camshaft & head.
(You can read about this in the tuning manual).
Our cams give substantially FLAT and exceptionally high torque delivery, which is a feature of the original engine as found on the TR5 & 2.5L saloons.

This is simply not possible in the USA, who had no experience whatsoever in race tuning small inline engines at all.
Most of US camshaft technology comes from V8 engines which almost inevitably have large bore/stroke ratios, short tracts & huge valves.
In this case they also had "poor man's Triumphs & Jaguars" running soft cams,low CRs & carbs, (preferring to drop in a large V8 instead when they could) instead of better tuning/Injection.

Ford Anglia, Standard Triumph, Austin A series, & Hillman slant 4 SOHC are engines extremely atypical of the USA.
This aspect is clearly shown by OEM/Works European cams which can be made to have better performance than any of the US "competition" ones,
needing very little lift in order to do it.
Some of these engines are perfectly capable of running in excess of 100bhp/L in road tune at 7000-10000rpm, something totally unheard of in the USA.

As for many of the FORD based profiles below, it's worth bearing in mind, ALMOST NO Triumph head will breath more over 0.430" lift (less on the exhaust).

We find an almost universal tendency to ADVANCE exhaust timing 10 degrees relative to the inlet,(FORD profiles). Isky refers to this as a "sloppy" way to do tractability.

We tested loads of heads, and almost invariably, breathing GOT WORSE as the valve opened more than 0.450", sometimes verging on catastrophe or collapse.
This is not suprising in view of the amateur way so called specialists do head work, & another reason why claims to such high powers from Kastner etc are simply NOT credible.
They SIMPLY COULD NOT have known what is going on in the head, because until very recently no-one bothered to find out!

Although this message has been repeated time & again:- I state again:- There is NO SUBSTITUTE for proper head work.

On our research heads we ware repeatedly able to get heads to breath proportionately more, the more the valve was lifted.
With careful attention to detail we are able to get more flow all the way up to 0.550-.600". This applied to every head we worked on except the Hillman imp,
(which has a finite amount of lift available), and even then we were able to get gains up to 0.500" which had never ever been seen before.

This is not the kind of performance possible for any normal head specialist working on an hourly rate.
We could make it possible, with 100s of hours work on valve design, exhaust manifolds, & porting.
(YOU NEED a proper exhaust to make use of these, not some nasty cheap S/S mass produced thing)

GT-6, Spitfire & TR camshafts
Camshafts from Standard Triumph & GTT (Good stuff in BOLD)
Application Part No Inlet opens BTDC° Inlet closes ABDC° Exhaust opens BBDC° Exhaust closes ATDC° Duration° Cam lift Valve lift Ideal hot clearance INLET Torque range Comments +ve & -ve
OEM. GT-6 Mk2, Spitfire Mk2/3, 2.5pi early 308778 25 65 65 25 270 0.238 0.340" 0.008"" 1200 to 6800 rpm This cam has best the performance of any road cam & runs well on Pi or SU carbs Has rather small lift so needs an exceptional head to get high powers ultimate power limited to peak 6600rpm, can get 75bhp/L!  
OEM. TR5/6 307689 35 65 65 35 280 0.252 0.360" 0.008" 2000 to 6800 rpm Excellent torque from factory cam, can be raised to very good state of tune, but again head/exhaust must be very good to get high power Also works v well on SUs/Spitfires, can be as high as 85bhp/L.
Although a torque improvement also can be made using a high ratio roller rocker on the INLET ONLY this cam tends to have high HC emission, because of overlap but low wear rates.
Camshaft 42 NLA GT-ST42 37 67 71 33 284 0.290 0.412" 0.010 2500 to 7000 rpm An unusually economical rally cam developed by John Reid for FORD Idle is rather rough on 2.5L, but runs quite well on 2L Pi & 1500cc Flat spots etc led to retirement of this profile & development of new ones.
Camshaft 43 CURRENT

This is the camshaft,
Triumph SHOULD have made.
GTT43 Time in at 108 deg n/a n/a n/a hybrid   0.390" .010" 2000-7500

Peak power at 7000

Tacho points to
6 o'clock!
A spectacularly successful "Wolf in sheep's clothing" profile with low wear rates. " but needs ideally 11:1 CR. The first road cam to date, capable of a genuine 100bhp/L, very impressive FLAT torque delivery with memorable rush from 5000rpm up. Idle is so smooth & exhaust so quiet, it fools people into sounding like a stock engine.

The initial impression soon disappears, but the exhaust is usually quieter than the induction (!) With the right anciliaries it gives excellent results on a 2.5L too.
Camshaft 42A CURRENT
GTT42A time in at 107 degrees n/a n/a n/a hybrid 0.300" 0.426" 0.010" 1800-7000 A v interesting cam for use where head skims (eg. GT6) can present problems 10-10.5:1CR Shorter duration than 43, with somewhat more lift, so peak torque arrives a little earlier. Suits a good flowed head to perfection giving 110ftlb torque from 1300 Spitfire (like 43) Smooth idle on weber or injection. Low wear rates, roughly similar power.
Camshaft 457 CURRENT
GTT457R time in at 102 degrees n/a n/a n/a hybrid 0.290" 0.415" 0.010" 2800-8000 Based on works camshaft family, so suits triumph engine perfectly Longer duration cam than 43, more lift, & a lot more zip at the top.
It still has a deceptively smooth idle & quiet exhaust but "comes on cam" VERY strongly at 4300rpm with an inlet "bark"
Smooth idle on weber or injection. Low wear rates. 140bhp possible,a bit mad for the road(!)

Needs 11:1 CR min.
Camshaft 55 CURRENT
GTT55 time in at 100 degrees n/a n/a n/a hybrid 0.327" 0.488" or 0.540" 0.018" 4400-9000 Based on a works camshaft & latest head work, so suits a properly modified triumph engine perfectly A longer duration cam than 457, with loads more lift, & a very strong top end. It has a smooth idle, but "comes on cam" quite viciously at 4500rpm extending to well beyond anything else done before Smooth idle on weber or injection.Can have higher wear rates, so has to have a proper head/steel followers.120bhp/L possible. Much superior to KC"264".

This is a proper race cam, & needs a high CR
Ancient (Kastner) Triumph Competition cams
Application Part No Inlet opens BTDC° Inlet closes ABDC° Exhaust opens BBDC° Exhaust closes ATDC° Duration° Cam lift Valve lift Checking clearance Operating clearance - hot Torque range Notes
S-2 street/race V 532 TSI/Isky now 31 71 71 31 282 0.270" 0.405" .013 .016 3500-6000 Described as a road/race cam! Narrow power band especially with the 6-2 exhaust type Idle quite rough, high fuel consumption
S-4 race V 579 TSI 42 71 71 42 293 0.273" 0.410" 0.013 0.020 4000-6800 This was described as a "race cam"! Narrow power band especially with the 6-2 exhaust type Rough idle, high fuel consumption
S-5 race V 688 37 73 73 37 290 .310 .465 .012 .017 4000-7000 Was described as an all out race cam!! Even Narrower power band. Probably wouldn't work today either on most heads, especially with the 6-2-1 exhaust Uses lift which probably is of no earthly use at the time it was released.
Good, bad or ugly aftermarket cams,based on Ford or various others.
Manufacturer, Application Part No Inlet opens BTDC° Inlet closes ABDC° Exhaust opens BBDC° Exhaust closes ATDC° Duration° Cam lift Valve lift Checking clearance Operating clearance Torque range Notes
Isky cam, road & race Z-19 24 64 64 25 268 .267" .400" .016" .018" 3000-6000 Similar to a "Witor" idea of a Spitfire Mk3/Pi cam with just more lift Just makes a little more torque.  
Isky Cam, Competition Z-66+10 31 71 71 31 282 .283 .425 .018 0.020 3500-6000 Supposed to be a substitute for S2 above I would imagine similar to SAH 357, ie. poor power delivery  
Kent Cam, Sports 'R' TH2-6 39 76 76 39 295 0.261 0.370"   2500-6500 This is a FORD BCF2 profile for a x-flow 1600 with the valve clearance run tight.  
Kent Cam, Sports 'R' TH5-6 Also called fast road 83 37 63 73 27 280 0.293" 0.416"   2200-7000 This is a FORD X-FLOW 234 CAMSHAFT Apparently works well with mediocre heads/valves.Has a pronounced flat 2800-3800 This is NOT a race cam. It is designed for a FORD 1600
Kent Cam, Supersports TH6-6 42 68 78 32 290 0.309" 0.439"   3000-7500 This is a FORD X-FLOW 244 CAMSHAFT This is NOT a race cam
Kent Cam, Race TH7-6 47 73 83 37 300 0.324" 0.460"   3800-7000 This is a FORD X-FLOW 254 CAMSHAFT This is claimed to be the ultimate Triumph race cam Far from perfect cam, designed for a FORD. Has a LOT of lift.
Kent Cam, RACE 264 52 78 88 42 310 0.339 0.480 0.020" 0.023" VERY CRITICAL 3700-8000 A cam for people who don't know about cams.

Has very good torque, but suprisingly restrained top end..so 8000 is way past peak power.
Although Torque is good, [Have seen as much as 125ftlb from a 1300(!)]
power peaks at around 7200.Came to be more or less a de-facto STD race cam for the Spitfire, where CR is not an issue.
BIG flat spots coming on cam. Can DO BETTER, because design is wrong for a Triumph.
Kent Cam, Sports Torque TH12-6 31 59 67 23 270 .287" 0.407"   1500-6500 This camshaft is a Ford 224 Profile.  
Piper Cam, Mild Road TR6BP255 17 55 55 17 252 .253 .380 .022   1000-5500 We do NOT recommend PIPER cams  
Piper Cam, Fast Road TR6BP270 24 60 60 24 264 .271 .406; .016 1500-6000 We do NOT recommend PIPER cams  
Piper Cam, Ultimate Road TR6BP285 36 68 68 36 284 .276 .414 .012   2500-6500 We do NOT recommend PIPER cams  
Piper Cam, Rally TR6BP300 44 76 76 44 300 .297 .445 .016   2800-7000 We do NOT recommend PIPER cams  
Piper Cam, Race TR6BP320 52 80 80 52 312 .327 .490 .014   3200-7500 We do NOT recommend PIPER cams  
Newman Cams, road/track PH3 40 80 80 40 300 0.290" 0.412" .020" .020 3500 - 7000 This Newman cam is from a design that has not changed in 30 years Newman cams have lower failure rates than most.
Tiltech?
Who are they anyway?
298 45 73 81 37 298 0.352" 0.499" .012" .015 4000-7000 This cam is supposed to be the result of amazing technical prowess.

To quote the designer, "These designs are better because they take advantage of the specific characteristics of the TR3/4 engine".
Well apparently they don't, because we have them here!
Flow from Inlet!

Exhaust flow is even weaker on one of these (full race) heads, than the inlet, making it pointless to exceed 0.360"-.380" lift

In the words of these people, "there is no downside to lift"!
Well we can assure you there is.
Also we note the "usual" advance of the exhaust timing by 8 degrees!
Tiltech? 310 52 78 84 46 310 0.380" 0.540" .012" .012 4500-7000 This cam is another showing that anybody armed with a PC nowadays thinks they can design/evaluate a camshaft.
People are swearing by these in Triumph circles!

We are starting to wonder how WE managed to get 100bhp/L from an engine with only 0.390" lift without using a computer?
This is not a silly reflection from us.
The hillman IMP engine (an ancient coventry made design) EASILY manages to run 100bhp/L figures & revs to
10 000rpm with only 0.360" lift.

Here are the flow bench curves for that, including how the head arrived & the improvement made after flowing it better,
(getting another 15bhp/1000rpm) in the process.
Maybe we do something wrong?
Canley
Classic?
/TLD?

Another one
who thinks
they can (re-)design a cam?
R2 37? 73? ? ? 285-290? 0.310?" 0.465" ?.020" ?.020" 4000 - 6500 This camshaft is clearly a retimed version of something else.(suspect based TH6 LATE)
To be quite honest we couldn't be bothered to waste time to find out what it is for sure!
NASTY!
we have rarely if ever seen such a truly AWFUL mess as this, The best description is a "lash-up".
We have never seen one of these work, & they knacker everything in an effort to struggle a few extra bhp out of what will be a horrible engine installation!
Racetorations

road/track

Another "so called" cam re-designer
555/777/888 ? ? ? ? 285-310 0.310-330" 0.460-500" Helpfully gives zilch details No idea & not interested 3500 - 7000 These have never been properly designed or tested, as they consist of "yet another rip off", of some old motorbike design.. These cams have higher failure rates than most, as the original pushrod (hemi) cam lobe shape was not designed for such high pressure.


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-Some of the info here (including code), was made available with thanks to some US contributors- We will update this later.