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Lotus in the Peak
28th - 30th June 2024

Sabre Heads Kr1 Plus Newman Phase 2 Cams


Phil S1

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Well it took me a while to figure it out but I've finally manage to plot the before and after graphs on a spreadsheet to make the comparison easier. I'll also hopefully be able to overlay this with the graph for the cams too after next week.

Rolling Road Graph.xls

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Yeah, that sounds like a good idea Bill, although I'm not registered on there so not sure how to go about it? How does the information need to be uploaded? The std engine rolling road figures I have are from a rolling road that no longer exists so I don't have the raw data for that one just the paper print but I can obviously read the data off that much like I did in my earlier attached file.

 

I went to work in the car today with the new regulator fitted, it ran just as well as before and didn't end in a fireball so I'm happy with that smile.png

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A few developments today....

The AFPR that Roger sells should also include a gauge to check the actual fuel pressure. Mine was initially missing from my order but Roger kindly chased it up and sure enough one was couriered to me today. Bit different to what I was expecting as they're filled with glycerine:-

IMG_8434_zps3d2e71ea.jpg

 

The gauge is not meant to be plumbed in permanently, once the correct pressure is set it is disconnected again. It screws into the side of the AFPR in place of the brass plug in this photo:-

IMG_8430_zpsdbe5782a.jpg

 

As you've probably already realised, this means there is a minor design flaw in the location of my AFPR. The gauge is going to foul on the boot divider wacko.gif

Fortunately, I reckon I'll be able to remove one of the mounting bolts and pivot the AFPR sufficiently to screw the gauge in....it's a good job all the connections are flexible! From previous experience, Roger reckons I'll need 46psi or 3.15 bar so I'll set it to that initially and then see what the air / fuel ratio looks like when we're on the rolling road.

Brian is coming up tomorrow to fit the cams and verniers so I've just got the car stripped down ready. Much the same as for a cambelt change I've removed the undertray, driver's side wheel and arch liner and cambelt cover. To make access a bit easier I've also removed the engine cover.

Removing the arch liner did afford a better photo of the AFPR and all it's plumbing. In hindsight, it would have made the initial fitting of the AFPR alot easier if I'd removed the arch liner then!

IMG_8441_zps053166f6.jpg

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No polishing Martin, just a bit of a wipe round smile.png

So yesterday didn't quite go to plan, as usual it's the little things that stall you on these jobs. Something I hadn't thought about was a distributor rotor drive. As per the Elise Parts write, up I can confirm that it is impossible to remove the distributor drive without destroying the drive or the camshaft. We could have ordered a new drive but with the Bank holiday that was likely to be Wednesday at the earliest and I'm due on the rolling road on Tuesday. So I let Brian loose with his angle grinder and sacrificed the old cam shaft.....there's no going back now!

There is quite a bit of fettling to be done on these jobs and the time just sailed by, the followers, all 16 of them, had to be planished such that they bed in with the new cams and the cams themselves required a light stoning to remove some sharp edges. It all takes time so we called it a day and plan to reconvene tomorrow, hopefully to get it all back together again.

Only took a few photos....

Cam cover and spark plugs removed..... MLOC plug retained wink.png :-

IMG_8442_zps2f56c145.jpg

 

Cam ladder and cams removed:-

IMG_8443_zpsc01dbc26.jpg

 

Cam ladder cleaned up, ready for sealant application:-

IMG_8454_zpsd00b604f.jpg

 

One last photo, Brian just couldn't let me have a knitting needle in my engine bay so he turned up something a bit more manly....heavier though!

IMG_8456_zpse724b04e.jpg

 

Swapped that over last night, to keep him happy!

 

Brian also turned me up the other item in the top left corner. This is something that Roger suggested I might need once the cams are in....more on that later.

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Brian made a return trip on Sunday and we set about getting it all back together, new cams in and the ladder all torqued up with a coating of sealant on the joint faces (you can just make out the yellow sealant around the joint):-

IMG_8485_zps450bebab.jpg

 

Next was the cambelt and tensioner and the distributor cap, before Brian set about getting the initial timing right. Roger recommends 40 thou on the exhaust and 50 thou on the inlet for the Newman phase 2 cams:-

IMG_8487_zps2cc59689.jpg

 

Once that was set we made sure the new cams were well coated with oil before quickly refitting the old cam cover gasket and the cover itself. One last check to make sure we'd not left anything off or any tools still lurking and then we fired it up. We ran at around 2500rpm for a good 20 minutes to bed the new cams in. As predicted by Roger there was a reluctance for the revs to drop back down to idle so we fitted the alloy restrictor that Brian had turned up previously. That did the job and we also had to then adjust the idle screw too to raise the tickover. I'm sure Roger won't mind if I quote him here:-

As I have mentioned too, on occasion on one or two cars the idle will not drop cleanly after revving, holding 1500-2000 rpm and gradually dropping. The fix so far has been to make a restrictor for the idle valve airfeed rubber pipe. Thus far a 5mm hole bored through a 15mm long bung that fits snugly into pipe- think dia is 16mm. I've been using Teflon style plastics from the nearby machining shop, he does a lot for the food industry & has bundles of spare metal/plastics for me to nab.

 

You will find a need to turn the idle speed up a tickle, if you don't adjust it enough you may find stalling occurs out driving & it will idle poorly- the odd customer has had that occur. If memory serves, about 900- 950rpm. You may find with time the car will settle & improve further.

Once everything had cooled down a bit we then removed the cam cover and re-checked the timing. A slight adjustment on the inlet side and all was good. As luck would have it, Brian had fitted a metric DTI on the outlet and an imperial one on the the inlet meaning it was exactly one revolution of each gauge to get the correct timing....made things nice and easy.

Brian had also made a pointer, mounting off one of the cambelt cover fixing screws, to indicate TDC:-

IMG_8490_zpsc63811fe.jpg

 

Once the timing was set, we then re-fitted the cam cover, this time with a new gasket. It was then a matter of re-fitting everything else, arch liner, undertray, wheel, engine cover and getting it back down off the axle stands.

Just had time to take the car out for a short run and settle things in a bit ready for the rolling road the next day. The car sounds a bit more purposeful now, much like Iain's sport 160 I think, mainly due to the more lumpy tickover. It also feels more lively, I still need to play around with the tickover a bit as it will stall occasionally when coming to a halt.

Thanks once more to Brian for making a second journey to get me up and running again plus a further thanks to Roger for all the info and tips he supplied along the way.

Rolling road results to follow soon....

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Today was one of those rare occurrences where my car had to get wet, but I had a 10.00am appointment back at Area 52 Autosport so needs must....

Arrived in good time and after the welcome mug of coffee and a bit of car shuffling mine was backed up onto the rollers. (I remembered to charge the batteries in my camera this time):-

IMG_8491_zpsb853a818.jpg

 

All the various probes and sensors installed and the road calibrated and we were good to go:-

IMG_8493_zpsddd9ca7b.jpg

 

Start the fans (sounds like Crystal Maze!) and then, once the car was fully warmed up, the first power run was underway:-

IMG_8494_zpsb0bc991c.jpg

 

The result wasn't quite what I was expecting, only gaining another 4 BHP to reach 147.3BHP. The torque remained fairly similar, losing some low down as expected but with some moderate gains higher up the rev range too. We had set the AFPR to 46psi as per Roger's recommendation and this seemed to be spot on. The guys tried lowering the pressure slightly to lean it off a bit but this made no significant gain on another power run, only another 0.1BHP.

 

I would liked to have seen something in the 150-155BHP range and am not quite sure what, if anything, might be holding it back a bit but that said I'm still liking the new sound and it has become more characterful to drive than previously. Early days yet, I need to get some fine weather miles under it's belt so no more tinkering just for now.

Jason printed me off a selection of graphs. Here are graphs of the basic KR1 (blue) overlaid with the Phase 2 cams and verniers (pink), the brown line being the one where they lowered the fuel pressure. First graph is power against torque:-

RollingRoadResultPh2vKR1_zps2734a23c.jpg

and here's the AFR:-

RollingRoadResultPh2vKR1-AFR_zpse6672c26.jpg

I'd be interested in people's thoughts. I'm still running a standard air filter and 48mm throttle body, might these be restricting things? I still have a cat fitted too but don't really want to remove that and make the car any more noisy. I guess, at some point, an Emerald might make a difference too but that'll have to be for another year. As I've said, the car still feels great and has definitely gained some character. I need some decent weather now to really drive it and see how it truly feels.

 

Thanks again to Jason and the team at Area 52

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