mjdm Posted August 29, 2006 Share Posted August 29, 2006 Finally got round to putting the VHPD head on last weekend. It is allegedly ex-Lotus and has had a bit of work done on it, mostly to the ports. I fitted this on to an 1800 block and (for reasons of lack of funds) reused the SS cams and followers (matching the followers to their relevent cam lobes. Set the cam timing (double and tripled checked that it was correct) and started the engine...hmmm it's a bit noisey ! Okay, the noise is most likely a lazy tappet (at least that's what it sounds like) on the exhaust side - that's where it sounds like it's coming from. However I am surprised at just how noisey it is, it certainly wasn't this bad before I did the head swap. It's also apparent that the engine has some issues, a slight hesitation when applying throttle and a bit of a flat spot around 3500rpm coupled with a disappointing performance at higher revs. Now I can accept that since I'm using the standard Rover ECU the fuelling and ignition will be out because of the head change but is this the sort of behaviour I should expect ? The idle is pretty rough (worse than before but it's never been that smooth) and coupled with the increase in top-end noise it is so far a bit disappointing. My next moves will probably be a programmable ECU (Emerald) and some verniers to time the cams correctly, but is there anything else I can do in the interim to a) sort out the noise (clean the followers ?) and b) improve the driveability. Thanks, Mike Link to comment Share on other sites More sharing options...
rj Posted August 29, 2006 Share Posted August 29, 2006 Some VHPD heads are not drilled for hydraulic followers, therefore, if yours are no mechanical, they may not be able to pump up. This'll make them noisy - and ruin the timing. /r Link to comment Share on other sites More sharing options...
mjdm Posted August 29, 2006 Author Share Posted August 29, 2006 I had wondered about that before getting the cylinder head, but it does indeed appear to have the oilways needed to feed the hydraulic followers. I had thought about using manual followers but was advised against it on the basis that this will ultimately be a fast road engine rather than a full race setup. Thanks, Mike Link to comment Share on other sites More sharing options...
rj Posted August 30, 2006 Share Posted August 30, 2006 For how long has the engine been running? I've seen hydraulic followers being noisy for close to 30 mins suddenly to become quiet. You are of course absolutely certain that you don't have air in your oil? /r Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted August 30, 2006 Leadership Team Share Posted August 30, 2006 Can we just run through the full spec Are we talking ...... 1800 bottom end VHPD head SS cams/Hydraulic followers Plastic plenum & TB Rover 1800 SS Mems As far as the poor running is concerned, you'll have messed up the mixture by using the big valve/high flow head - you're fuelling is likely weak. This can maybe be improved a little by incrasing the fuel pressure? If you're planning to go to an Emerald, and probably TBs, do it now! Tappets - are they definately hydraulics - ie. this isn't an ongoing conversion from something like a 1400 racer that had solid tappets? Or have they been stored for a while the wrong way up and lost their oil (shold be stored upside down, therefore it'll take a while to refill? Don't underestimate the oil drilling issue. I've known of hydraulic tappets that have been transferred from one K16 head to another and had issues over the position of the drillings. I would think this is the most likely issue. Where's Oily? Stu. Link to comment Share on other sites More sharing options...
Englishmaninwales Posted August 30, 2006 Share Posted August 30, 2006 '' However I am surprised at just how noisey it is, it certainly wasn't this bad before I did the head swap'' ''Don't underestimate the oil drilling issue. I've known of hydraulic tappets that have been transferred from one K16 head to another and had issues over the position of the drillings. I would think this is the most likely issue.'' I know of 2 standard K16 heads ( including mine!) where the drillings for the camfollower oil feed were poorly positioned, on the exhaust side in my case. The engine sounded dreadful and some cam followers never filled. With the cam carrier off and the follower in place, look down the oil feed hole with some light, you should be able the groove in the follower. In my case I had to open out the bottom end of the oil feed with a Dremel. Malcolm Link to comment Share on other sites More sharing options...
mjdm Posted August 30, 2006 Author Share Posted August 30, 2006 Thanks for the advice guys. The engine has run for about 30 mins in total since I did the swap. Stu, yes you got the spec correct. I am expecting the fuelling to be off for exactly the reasons you state (bigger valves, more flow) so the uneven performance is not unexpected (an Emerald is next on the shopping list), its the noise that surprised me. One option might be to just run the engine for longer on the basis that one of the tappets still hasn't pumped up. Presumeably the Apollo tank will reduce the likelihood of aerated oil. I'll do as suggested and get the carrier off and reinspect the tappets and the oilways for clearance, I guess the next thing would be to inspect the tappets for blockages (yes they are hydraulic tappets) Thanks, Mike Link to comment Share on other sites More sharing options...
rj Posted August 30, 2006 Share Posted August 30, 2006 Mike, I wouldn't run the engine at higher RPM if it runs lean, no engine quite likes that... Link to comment Share on other sites More sharing options...
Jason Plato Posted August 30, 2006 Share Posted August 30, 2006 if you fit an emerald then you should be able to keep the plenhum . This is similar to the setup that Angus has Link to comment Share on other sites More sharing options...
oilyhands Posted August 30, 2006 Share Posted August 30, 2006 If you are retaining the VHPD caps, these do not work with hydraulic followers, the follower nose fouls on the shim support ring on the cap rather than tocuhing the end of the valve stem, this causes two problems i) the valves are held slightly open all the time ii) as the cam lifts the cap is dislocated from the collets and valves and the collets will eventually drop out resulting in a dropped valve or two. The cap dislocation is what makes the noise. On no account run the engine again!!!! Either swap the caps for regualr ones or mahcine off the shim support ring. Oily Link to comment Share on other sites More sharing options...
mjdm Posted August 30, 2006 Author Share Posted August 30, 2006 Cheers for the info Dave. I'll take the head off this weekend and double check which caps are actually fitted. I'd been told that the valve/spring/cap assembly would be okay for the SS cams - but of course they then need the hydraulic followers - and so it sounds like this is the problem. I'll be more careful who I get info from in the future :-) Thanks, Mike Link to comment Share on other sites More sharing options...
Rob Walker Posted August 30, 2006 Share Posted August 30, 2006 You don`t need to take the head off to check the spring retainers just remove the cam ladder and cams. Link to comment Share on other sites More sharing options...
mjdm Posted August 30, 2006 Author Share Posted August 30, 2006 Rob, thanks, I realised I was being daft after I posted it my excuse is I've just got back from a friends wedding and am feeling a little jaded . I was also working on the worst case scenario and readying the wife for my absence to the garage for most of the weekend... Cheers, Mike Link to comment Share on other sites More sharing options...
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