wimpus Posted June 30, 2021 Report Share Posted June 30, 2021 Hi all, I've been planning an engine rebuild on my Spit 1500 engine with 324.000kms/201.000miles. Its using a fair bit of oil. Last year changed the head etc. It needs a re-bore, crank re-grind etc. Soo.. Been thinking of fitting an MK3 profile cam. What are the positive and negative things fitting it? Also pistons, what are the best to use ? county, nüral ? Bearings: county 3 metal, glyco ? Link to comment Share on other sites More sharing options...
Clive Posted June 30, 2021 Report Share Posted June 30, 2021 Not many disadvantes to the mk3 cam, it is just a bit "warmer" but not "hot". It was used on 2.5 engines so will be fine with a 1500 which is broadly similar. Bearings, if you can find VP2, they would be best. If not, glyco/AE/glacier, then county. Pistons, I believe county are fine. Got some here for a TR7, the company who did the rebore were happy with them, all measured identical diameter, and very close on weight, well within limits. 1 Link to comment Share on other sites More sharing options...
Nigel Clark Posted June 30, 2021 Report Share Posted June 30, 2021 8 minutes ago, clive said: Not many disadvantes to the mk3 cam, it is just a bit "warmer" but not "hot". It was used on 2.5 engines so will be fine with a 1500 which is broadly similar. Bearings, if you can find VP2, they would be best. If not, glyco/AE/glacier, then county. Pistons, I believe county are fine. Got some here for a TR7, the company who did the rebore were happy with them, all measured identical diameter, and very close on weight, well within limits. +1 The Mk3 cam profile is the best for road use. More at the top end than other factory cam profiles, with no significant loss of of low down torque. I've used County bearings and pistons, which seem fine. There have been past concerns about dimensional consistency of County pistons. I used them for a 6 cylinder engine rebuild two years ago. When my trusted machinist measured the new pistons they were all very, very similar. Nigel Link to comment Share on other sites More sharing options...
wimpus Posted June 30, 2021 Author Report Share Posted June 30, 2021 8 hours ago, clive said: Not many disadvantes to the mk3 cam, it is just a bit "warmer" but not "hot". It was used on 2.5 engines so will be fine with a 1500 which is broadly similar. Bearings, if you can find VP2, they would be best. If not, glyco/AE/glacier, then county. Pistons, I believe county are fine. Got some here for a TR7, the company who did the rebore were happy with them, all measured identical diameter, and very close on weight, well within limits. Seen a dutch supplier selling re-grounded cams to mk3 profile. Would that be trusted ? I had the bearing numbers om my friend his TR6 build, the machine shop ordered Nüral pistons and Glyco bearings. So got the part no. Sadly non to find.. Link to comment Share on other sites More sharing options...
Nigel Clark Posted June 30, 2021 Report Share Posted June 30, 2021 21 minutes ago, wimpus said: Seen a dutch supplier selling re-grounded cams to mk3 profile. Would that be trusted ? I had the bearing numbers om my friend his TR6 build, the machine shop ordered Nüral pistons and Glyco bearings. So got the part no. Sadly non to find.. Best to get a cam that has been ground on a brand new blank, from a reputable supplier. Reprofiling a worn cam as the surface hardening will be thin, risking rapid wear. Nigel Link to comment Share on other sites More sharing options...
wimpus Posted June 30, 2021 Author Report Share Posted June 30, 2021 1 hour ago, Nigel Clark said: Best to get a cam that has been ground on a brand new blank, from a reputable supplier. Reprofiling a worn cam as the surface hardening will be thin, risking rapid wear. Nigel Ok, will contact the seller. Otherwise I will need to stick with my standard one... thanks to brexit. Link to comment Share on other sites More sharing options...
wimpus Posted June 30, 2021 Author Report Share Posted June 30, 2021 Only other place that I found to sell the mk3 profile on large journals.. https://www.canleyclassics.com/?product=camshafts But in the UK.. Link to comment Share on other sites More sharing options...
Clive Posted June 30, 2021 Report Share Posted June 30, 2021 Newman cams produce some high quality stuff, including followers. But again in the UK... What about Bastuk? Link to comment Share on other sites More sharing options...
wimpus Posted July 1, 2021 Author Report Share Posted July 1, 2021 11 hours ago, clive said: Newman cams produce some high quality stuff, including followers. But again in the UK... What about Bastuk? Had a look on newman cams and bastuck. Ph1 of newman is pretty close to mk3 spec. But again bastuck doesnt sell anything like mk3 cam that fits in a 1500. Only mk3 cams with cam bearings. Link to comment Share on other sites More sharing options...
DanMi Posted July 1, 2021 Report Share Posted July 1, 2021 I may be wrong but wouldn't putting bearings in the 1500 block mean that you can use a mk3 small journal cam. In the early mk2 the cam ran directly in the block, they then bored the block to accept bearings with the same cam (identical to mk3) then during the mk4 run they stopped using bearings and used a cam with bigger journals to fit the block. 1 Link to comment Share on other sites More sharing options...
wimpus Posted July 1, 2021 Author Report Share Posted July 1, 2021 2 hours ago, DanMi said: I may be wrong but wouldn't putting bearings in the 1500 block mean that you can use a mk3 small journal cam. In the early mk2 the cam ran directly in the block, they then bored the block to accept bearings with the same cam (identical to mk3) then during the mk4 run they stopped using bearings and used a cam with bigger journals to fit the block. Yes i know that I could use cam bearings. But in my opinion, another thing that can go wrong.. As I do a lot of kms/miles, want it 'sort off' bullet proof. Link to comment Share on other sites More sharing options...
Peaks Posted July 1, 2021 Report Share Posted July 1, 2021 On 30/06/2021 at 09:01, clive said: Not many disadvantes to the mk3 cam, it is just a bit "warmer" but not "hot". It was used on 2.5 engines so will be fine with a 1500 which is broadly similar. It has the same valve timing as the TR5/early 6? I as as I was considering this cam profile for my MkII Vitesse, but was concerned that I'd loose the smooth idle and low down torque. Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 1, 2021 Report Share Posted July 1, 2021 6 minutes ago, Peaks said: It has the same valve timing as the TR5/early 6? I as as I was considering this cam profile for my MkII Vitesse, but was concerned that I'd loose the smooth idle and low down torque. No, it's the same as the later TR6 PI (CR series). Has less dwell than the early TR6. Nigel Link to comment Share on other sites More sharing options...
Peaks Posted July 1, 2021 Report Share Posted July 1, 2021 Thanks Nigel, the amount dwell is what I was wondering about. Link to comment Share on other sites More sharing options...
thescrapman Posted July 1, 2021 Report Share Posted July 1, 2021 10 hours ago, wimpus said: Yes i know that I could use cam bearings. But in my opinion, another thing that can go wrong.. As I do a lot of kms/miles, want it 'sort off' bullet proof. I would have thought it would be no less reliable with Cam bearings, especially as original is for cam to run in the block itself. do not be tempted to fit stronger valve springs. Link to comment Share on other sites More sharing options...
wimpus Posted July 2, 2021 Author Report Share Posted July 2, 2021 On 01/07/2021 at 22:22, thescrapman said: I would have thought it would be no less reliable with Cam bearings, especially as original is for cam to run in the block itself. do not be tempted to fit stronger valve springs. Colin, I do now have double valve springs are original 1500 spec. Would this still be good ? 🤔 Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 3, 2021 Report Share Posted July 3, 2021 i think Colin is concerned that stronger than std and higher cam lifts puts unwanted strain on the cam and its block journals if the block bores wear youre in trouble pete Link to comment Share on other sites More sharing options...
Nick Jones Posted July 3, 2021 Report Share Posted July 3, 2021 On 01/07/2021 at 15:10, Nigel Clark said: No, it's the same as the later TR6 PI (CR series). Has less dwell than the early TR6. No, it’s the same 25/75 profile as used for the Mk2 Vitesse/GT6 and Mk1/early Mk2 PI saloons. 308778 cam for the 6cyl. Good all-round road cam that works well with CD carbs (TR5/early 6, not so much, too much overlap) Nick Link to comment Share on other sites More sharing options...
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