cammmy Posted February 28, 2014 Share Posted February 28, 2014 Hi GuysI'm heading home for a Month in late March. Planning to drop out the 6 I put in and put back the motor it came with on SU carbs. Also thinking about whipping the head off and doing some minor port shaping/valve de-shrouding, maybe a head skim, valve back cuts and radiused corner (on exh) etc (My brother is an engineer so should be no problem doing the skimming and valve work.)My question is. If I'm running the stock 18-58-58-18 cam, how much should I look at taking off the head if I run on 98 ron?Also, with those timings, I'm getting 256 degrees of duration on a 110 LSA and 36 degrees of overlap? Is that correct? Isn't that quite a hot cam for a motor like this (that puts out well under 50HP per litre)? Quote Link to comment Share on other sites More sharing options...
Richard B Posted February 28, 2014 Share Posted February 28, 2014 If your taking the head off, maybe you should fit a 2.5PI 132bhp cam at the same time? :-/ :) Quote Link to comment Share on other sites More sharing options...
cammmy Posted February 28, 2014 Author Share Posted February 28, 2014 I would but this is really just a stop-gap until I'm home for good and can build the V8. Not looking to spend any money on it other than new gaskets.It's also a good chance to get some practice in with the grinder before moving onto heads I don't want to have to throw away. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted February 28, 2014 Share Posted February 28, 2014 I can't tell you how much to take off the head but I recommend not going above 9.0:1 compression ratio with that cam. Original is probably 8.5:1 dependent on what you are starting from.http://www.triumphclub.co.nz/?page_id=653Nick Quote Link to comment Share on other sites More sharing options...
cammmy Posted March 2, 2014 Author Share Posted March 2, 2014 Cool, I believe my head is an 8.5:1 MM unit. I'm quite happy to only run it on 97 RON. Would you still stick to 9:1 on the good stuff or go a bit higher? Quote Link to comment Share on other sites More sharing options...
TedTaylor Posted March 3, 2014 Share Posted March 3, 2014 I do consider that up to 9.5 is all right for most of our engines.The 2500 engine transplanted by the previous owner into my Mk2 is an 'S' engine that has been significantly worked to produce excellent useable all round performance on original spec. SU carbs with full (6 branch twin silencer) CW exhaust system. It is the car that I use for everything including towing the caravan, trailers full of garden rubbish to the tip (with much inside the back of the car) and down the scappy with loads of metal to be weighed in. Lovely smooth tractable engine but most importantly running on 9.25:1 compression ratio. When I mentioned to Chris Witor who the previous owner had gone to for advise on how to get the engine built to the above spec., that I was thinking about going down the PI route some time in the future his main comment was that I should make sure I get the CR up to 9.5:1.MUT Quote Link to comment Share on other sites More sharing options...
cammmy Posted March 3, 2014 Author Share Posted March 3, 2014 Brilliant. When I'm back I'll have to measure everything up and work out how much to take off.taCam Quote Link to comment Share on other sites More sharing options...
TedTaylor Posted March 3, 2014 Share Posted March 3, 2014 Cammy I'll scan and send you the build info sheets and receipts describing the work done when I get a chance. About the only query that I have with the mechanics of the car is that I don't like the clutch action. Works but does not have a nice feel, but as I have lots of other things to worry about at the moment (two Mk1s to sort for the RBRR and my knee operation coming up soon) there are more important things to do first!!!!MUT Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted March 3, 2014 Share Posted March 3, 2014 Ted, I wasted alot of time (and money) trying to make the LH pedal of my PI feel like a "normal" clutch pedal. So far I've failed, but as it does actually function as a clutch pedal (and apparently has a lighter action than many) I've given up for now.Nick Quote Link to comment Share on other sites More sharing options...
cammmy Posted March 3, 2014 Author Share Posted March 3, 2014 Cool thanks. I'm just looking to do what I can for free for a bit of fun while the engine is out.They certainly are a heavy clutch! I don't mind that though. Quote Link to comment Share on other sites More sharing options...
TedTaylor Posted March 3, 2014 Share Posted March 3, 2014 Nick_Jones wrote:Ted, I wasted alot of time (and money) trying to make the LH pedal of my PI feel like a "normal" clutch pedal. So far I've failed, but as it does actually function as a clutch pedal (and apparently has a lighter action than many) I've given up for now.NickNick I will leave it for now as I am of a similar opinion to you though the missus does find the car difficult to drive, and have the two Mk1s to get sorted for the RBRR with my op. which is due soon to get in the way! My Mk1 saloon and old Mk2 PI saloon both had lovely clutch actions :-/MUT Quote Link to comment Share on other sites More sharing options...
Greeks Posted March 4, 2014 Share Posted March 4, 2014 My clutch is rubbish too ... interesting that.Mind it's nowhere near as heavy as the clutch on the TD5 Defender we've got. And as my wife mainly drives that in the warmer months (for the A/C) she doesn't complain. Quote Link to comment Share on other sites More sharing options...
Greeks Posted March 4, 2014 Share Posted March 4, 2014 My clutch is rubbish too ... interesting that.Mind it's nowhere near as heavy as the clutch on the TD5 Defender we've got. And as my wife mainly drives that in the warmer months (for the A/C) she doesn't complain. Quote Link to comment Share on other sites More sharing options...
andy thompson Posted March 4, 2014 Share Posted March 4, 2014 My clutch on my white PI is lovely - light and progressive (Borg and Beck), my 2100 is fine too (Laycock) , My Stag is awful - Borg and Beck. I had an old 2500 Laycock in my white PI - that was heavy and gritty and before that a Sachs (Saab?) - light and nice.Its a lottery to be honest Quote Link to comment Share on other sites More sharing options...
Steve P Posted March 4, 2014 Share Posted March 4, 2014 In my Vitesse(2.5 and Saloon box)the clutch was notchy with no feel,it has an Ap clutch.The biggest improvement i found was fitting the old brass bearing carrier back in,now its smooth and light.Steve Quote Link to comment Share on other sites More sharing options...
dazzer Posted March 4, 2014 Share Posted March 4, 2014 I have an AP racing clutch and it is fine but does get notchy after the clutch lever (where the cotter pin connects to the slave)has been submerged. Re grease or wd for a quick fix and its ok again. Comp ratio on my early 2000 mk1 is 10.75.1. With a pi cam and retarded advance curb 13deg on an original dizzy. Reliable and really gutsy. 40k so far. Quote Link to comment Share on other sites More sharing options...
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