LEETR4A Posted February 11, 2011 Report Share Posted February 11, 2011 Hi all I know it's a subject that has been discussed before, but i'm still unsure what to do. I've just stripped what was supposed to be a fast road engine built by a known 'specialist', because it has never run right in the 4k miles since the car went back on the road. Although some areas seem to be ok, others have been disappointing considering what I paid at the time to have it built about 6 years ago. The godd bits are: balanced bottom end and Glacier bearings 86mm +.040 pistons and liners gas flowed head with matched ports and hardened inserts Not so good: A mismatch of exhaust valves and wear already on the stem of one of the inlet valves What seems to be (according to the part number) a 2 litre TR3 camshaft!!!(there are no other markings) My dilema is that I obviously need to replace the valves, but with the spec that I have, which is the best 'fast road'camshaft to go for to give good low down and mid range power, but also giving a smooth tickover (something which I never had with the old setup). I have been looking at the Piper BP270, the Newman PH1 and the Kent Sport R, but would appeciate any input from those who have already gone through this.I need to be able to try and keep up with North London Mike's rally rep TR4 (I wish). Thanks in advance Lee Quote Link to post Share on other sites
LGFromage Posted February 11, 2011 Report Share Posted February 11, 2011 Over the years I have purchased for my 4A 2 Piper camshafts, the second to replace the first. When the second one was bought I noticed that the base circle diameter of each cam on both shafts varied significantly. This makes a mockery of reduced length pushrods. It should be noted that the original standard TR camshaft had base circles all of the same diameter. Therefore whatever cam you buy I suggest that you make a quick check of the base circle diameters to ensure that they are all the same thereby allowing each cylinder to have matched valve timings. No doubt this will be beneficial for engine performance. Tim Quote Link to post Share on other sites
BrianC Posted February 12, 2011 Report Share Posted February 12, 2011 Not so good: ...What seems to be (according to the part number) a 2 litre TR3 camshaft!!!(there are no other markings) Could this be because an original camshaft has been reprofiled? [i ask simply because I don't know whether old camshafts are reused in this way.] Quote Link to post Share on other sites
ianc Posted February 12, 2011 Report Share Posted February 12, 2011 The excessive wear on the valve(s) might be the result of the length of the pushrod(s) being incorrect - if the head is skimmed to increase compression ratio, the pushrods need to be shortened to maintain the correct operating angle for the rockers. Camshaft: I would talk to a reputable supplier about what sort of performance you want from your car - it sounds to me as if a Rally cam profile is what you need. That is what is in my car (4VC) and Mike's LNK, and you can see the sort of torque and power profiles those provide by referring to my article in TR Action 238 (October 2009), pages 28-31. Manvers fettled Mike's car (and 7VC of Jonathan Hancox), Neil Revington did mine (and looks after 3VC and 6VC, and has been rallying for some 30 years). I know that Lee Hutton of North London Group has found his camshaft completely unsuitable for road use (sweet f.a. below about 3,300 rpm!) and is planning a change to something more suitable. My car can be driven at 1,800 rpm (30 mph in overdrive 3rd) and pulls well from about 2,300 to be exceeding the torque of a standard TR4 from 2,900 onwards. Ian Cornish Quote Link to post Share on other sites
LEETR4A Posted February 12, 2011 Author Report Share Posted February 12, 2011 Hi Ian It is me (Lee Hutton) who has the dilema. I have spoken to Clive Manvers who recommends the Piper cam for my car although Mike North has the Kent fitted and I know that Menno on the forum has just fitted the Newman cam, but has yet to try it. I would just like a little feedback from those who have any of these cams fitted as to how they perform. According to the specs that I can find the power pick up is as follows: Piper 1300 - 5500 rpm Newman 1300 - 5500 rpm Kent 2200 - 7000 rpm I will check with Revingtons to get their feedback. Lee Quote Link to post Share on other sites
LGFromage Posted February 12, 2011 Report Share Posted February 12, 2011 I may moan about the accuracy of base circle diameters on camshafts purchased new some time ago (they mey be better now) but I am quite pleased with the performance aspects. My Piper camshaft has the same timing profiles as the Sprint variant in the Moss catalogue. It is running with a raised compression ratio and standard TR4A exhaust. The result is a tractable revvy engine which idles nicely. I run it on Shell Optimax or equivalent which it likes, though it can run on a bit on shut down. Overall the car is a bit more sporty than standard but is by no means an out and out racer, which suits me just fine. Good luck with whichever cam you select - any feedback would be interesting to hear. Tim Quote Link to post Share on other sites
Badfrog Posted February 14, 2011 Report Share Posted February 14, 2011 Hi all, I'm jumping on the discussion to try to figure out my own cam. This one has been installed years ago, on a previous engine (around 1980) then transferred to the present engine and is still in good specs in terms of lift. The problem is that I don't know which cam it is. Chris and I are trying to sort it out. We first realized that TDC was off by 6° but this will be easy to reset. Then the diagram: "open" is 40-91 and "close" is 90-52. This gives a 90° overlap and is obviously a full race diagram. The problem is that I can't trace it from any of the 20 or so suppliers I know of. I would also like to know the valve play that should be used when measuring the camshaft diagram (not the valve play when the engine is working, that's 0.36 mm i.e. 0.014" all over in my case) Light anybody? Cheers, Badfrog Quote Link to post Share on other sites
Guest ntc Posted February 14, 2011 Report Share Posted February 14, 2011 Hi all, I'm jumping on the discussion to try to figure out my own cam. This one has been installed years ago, on a previous engine (around 1980) then transferred to the present engine and is still in good specs in terms of lift. The problem is that I don't know which cam it is. Chris and I are trying to sort it out. We first realized that TDC was off by 6° but this will be easy to reset. Then the diagram: "open" is 40-91 and "close" is 90-52. This gives a 90° overlap and is obviously a full race diagram. The problem is that I can't trace it from any of the 20 or so suppliers I know of. I would also like to know the valve play that should be used when measuring the camshaft diagram (not the valve play when the engine is working, that's 0.36 mm i.e. 0.014" all over in my case) Light anybody? Cheers, Badfrog Hi Mr Badfrog as Pink would say There seems to be a lot of talk about cams good and bad on here recently,the main things you must consider if the cam is a good one? Always time the cam allowing for valve clearance Whatever comes off the head to get the best result out of the cam must be replaced ie shimmed pillers etc Check push rod length Quote Link to post Share on other sites
ianc Posted February 14, 2011 Report Share Posted February 14, 2011 Whilst you can compensate the valve geometry for the metal skimmed off the head by standing the rocker assembly on pillars equal in height to the amount of metal taken from the head, and then winding the tappet adjusters out, it is not the best way to tackle the problem. The engineering solution, as Kastner describes in his excellent manual (available from the Register shop), is to shorten the pushrods. Kas advises that each pushrod be reduced in length by three-quarters of the amount taken from the head, then each pushrod should be measured and adjusted individually. As he points out, you can't put metal back if you remove too much! Kas says that when the valve is half open, the rocker arm and the valve stem centre line should be at right angles (90 degrees). If the geometry is off, you will have excess valve guide wear, and also a rounding of the valve stem ends. Ian Cornish Quote Link to post Share on other sites
Guest ntc Posted February 14, 2011 Report Share Posted February 14, 2011 Whilst you can compensate the valve geometry for the metal skimmed off the head by standing the rocker assembly on pillars equal in height to the amount of metal taken from the head, and then winding the tappet adjusters out, it is not the best way to tackle the problem. The engineering solution, as Kastner describes in his excellent manual (available from the Register shop), is to shorten the pushrods. Kas advises that each pushrod be reduced in length by three-quarters of the amount taken from the head, then each pushrod should be measured and adjusted individually. As he points out, you can't put metal back if you remove too much! Kas says that when the valve is half open, the rocker arm and the valve stem centre line should be at right angles (90 degrees). If the geometry is off, you will have excess valve guide wear, and also a rounding of the valve stem ends. Ian Cornish Correct Ian I should put 3 as number 2 but it can be a compromise Quote Link to post Share on other sites
harrytr5 Posted February 15, 2011 Report Share Posted February 15, 2011 Hi all I know it's a subject that has been discussed before, but i'm still unsure what to do. I've just stripped what was supposed to be a fast road engine built by a known 'specialist', because it has never run right in the 4k miles since the car went back on the road. Although some areas seem to be ok, others have been disappointing considering what I paid at the time to have it built about 6 years ago. The godd bits are: balanced bottom end and Glacier bearings 86mm +.040 pistons and liners gas flowed head with matched ports and hardened inserts Not so good: A mismatch of exhaust valves and wear already on the stem of one of the inlet valves What seems to be (according to the part number) a 2 litre TR3 camshaft!!!(there are no other markings) My dilema is that I obviously need to replace the valves, but with the spec that I have, which is the best 'fast road'camshaft to go for to give good low down and mid range power, but also giving a smooth tickover (something which I never had with the old setup). I have been looking at the Piper BP270, the Newman PH1 and the Kent Sport R, but would appeciate any input from those who have already gone through this.I need to be able to try and keep up with North London Mike's rally rep TR4 (I wish). Thanks in advance Lee What goes round, comes round, Lee and NLG know,s who the culprit is. Now Lee wants more feed back from owners who have installed camshafts with very good success,can you help.It wiil be touch and go wether both cars will be ready for our TRia NLG tour in April so any help on Lee,s quest will be most appreciated. Regards Harry TR Nutter Quote Link to post Share on other sites
MadMarx Posted February 15, 2011 Report Share Posted February 15, 2011 (edited) .....Kas advises that each pushrod be reduced in length by three-quarters of the amount taken from the head, then each pushrod should be measured and adjusted individually. As he points out, you can't put metal back if you remove too much! Kas says that when the valve is half open, the rocker arm and the valve stem centre line should be at right angles (90 degrees). If the geometry is off, you will have excess valve guide wear, and also a rounding of the valve stem ends. Ian Cornish I might point out that Kas was referring to competition pushrods he used in that time and also shown in that manual he wrote then. You can't do that with the stock tube pushrods as the heads are welded in. The ones he had were press fit ones. On my car I did shim my pedestals and I found almost no wear on these parts from that. My guides are 8 year old, I replaced the valves after 10 years of running as they wear out. But with racing the wear is a little higher than with road use. Cheers Chris (BTW...Kas is coming to Germany this summer) Edited February 15, 2011 by MadMarx Quote Link to post Share on other sites
Guest ntc Posted February 15, 2011 Report Share Posted February 15, 2011 What goes round, comes round, Lee and NLG know,s who the culprit is. Now Lee wants more feed back from owners who have installed camshafts with very good success,can you help.It wiil be touch and go wether both cars will be ready for our TRia NLG tour in April so any help on Lee,s quest will be most appreciated. Regards Harry TR Nutter Harry Only half the story sorry if the NLG knows something then they should say so !!!!!!!!!! ~Yes I will help Lee if we are not talking riddles Quote Link to post Share on other sites
Tr4Tony Posted February 15, 2011 Report Share Posted February 15, 2011 Hi Sounds like you need to start from some known territory with a properly made cam and some standard pushrods and rocker gear. This is effectively what I use in BST82B and similarly 3VC so by no means do you need to get into custom making bits and pieces unless you are going go racing. Even then reliability is everything. My advice would be to talk to someone like Neil Revington or Steve Hall, both of whom know what they are talking about and have done it countless times with much success. If I can rally a car successfully with their respective cams and parts, then you can be assured that they are good. If you want to pm me off line I can tell you what I use, but Im sure you will want something milder, but equally reliable.. Regards Tony Quote Link to post Share on other sites
Badfrog Posted February 16, 2011 Report Share Posted February 16, 2011 Hi guys, Some answers: Camshaft diagram shoud be measured with a 0.040" (1 mm) valve lash. Initial setting at installation goes from 103° ATDC (Revington) to 111.5°, stock cams being set at 110°. A useful adress and some more : http://www.tildentechnologies.com/Technical/TriumphCams.html#TR234 http://www.auto-ware.com/combust_bytes/camfund.htm http://www.burtonpower.com/tuning-guides/tuning-guide-pages/camshaft-fitting-timing.html http://www.moss-europe.co.uk/graphics/uk/instructions/TR2-4A_CAMSHAFTS.pdf Hope this helps. Badfrog Quote Link to post Share on other sites
Guest ntc Posted February 16, 2011 Report Share Posted February 16, 2011 (edited) Hi guys, Some answers: Camshaft diagram shoud be measured with a 0.040" (1 mm) valve lash. Initial setting at installation goes from 103° ATDC (Revington) to 111.5°, stock cams being set at 110°. A useful adress and some more : http://www.tildentechnologies.com/Technical/TriumphCams.html#TR234 http://www.auto-ware.com/combust_bytes/camfund.htm http://www.burtonpower.com/tuning-guides/tuning-guide-pages/camshaft-fitting-timing.html http://www.moss-europe.co.uk/graphics/uk/instructions/TR2-4A_CAMSHAFTS.pdf Hope this helps. Badfrog Badfrog The Burton reference is as good as it gets imho,and remember a good sign you have got it right is instant start. Harry mail sent to Lee Edited February 16, 2011 by ntc Quote Link to post Share on other sites
PaulAnderson Posted February 18, 2011 Report Share Posted February 18, 2011 Out of curiosity, which cam does TS2 have fitted? When I got to drive it I was impressed with it's power delivery under normal driving conditions (I did not dare drive it hard) Paul Quote Link to post Share on other sites
Dave Satchwell Posted February 18, 2011 Report Share Posted February 18, 2011 My car has the same cam fitted as TS2, which is a Piper mild road cam ( 3TY spec ). Every thing else is standard on the car (TR3a), it is tractable from low revs and pulls cleanly through the rev range. I wanted a cam slightly hotter than standard with none of the down side associated with "hot cams". It also returns an average of 30mpg and as things are at the moment that has to be a consideration, Dave Quote Link to post Share on other sites
LEETR4A Posted March 21, 2011 Author Report Share Posted March 21, 2011 Hi all I finally decided on the Kent Sport R camshaft for my engine. Mike North has one in his rally rep 4 and it gives a very good power delivery and seemed to stack up well against the other options available. It was also at a very good price from Larkspeed. One question. I have been told that if you advance the camshaft timing by a couple of degrees when you set it up, it will increase low to mid range torque and if you retart it a couple of degrees it will increase top end power. Is this correct and is it worth doing? I would go for the torque option. Regards Lee Quote Link to post Share on other sites
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