Hillman Imp how to dial in a unknown race cam- GB 72

having just played this video back i realised there is a massive error in my settings!! see if you can spot it?

[stevecmason-rsvf]

Great video and explanation. I have to admit as you presented the dowel to the camshaft I was thinking, no don't drop it please don't drop it into the engine😮 as I have done similar!
Keep the videos coming please, they are truly hands on engineering.

[LouKodge]

I remember back in 1970 in Sydney Aust. there was a a V8 Imp that raced in sports car category. It went like stink in the straights, passed everyone, but got caught in the corners because they couldnt get it to handle, sadly.

[stevehobbs]

Alright my mate, wish I'd have known the TDC trick a few years ago, loving the channel.

[havenview]

Love the camera falling over bit - you planned that all along right?

[lotus-e-clan]

Back again. George Bevan consulted with Piper cams. So the BP cams on Imps4ever are Bevan Piper. I think the GB 72 lies somewhere between the BP 300 (fast road- comp) and the BP 320 (race) on the list. It's supposed to be a relatively torquey cam, that's why it works ok for me on the road. That said, I'm running a std box instead of my 1/2 Knight sc cr box on the new build and l preferred it with the cr box for a B road blast in the Dales! Just that 5800 rpm at 70 mph in top is a tad noisy for the road.

[chevyimp]

Wow ... Another gem of a video.. thanks for the lesson.

[chrisval]

It would have been interesting to see what the full lift on #1 inlet figure was.

[lotus-e-clan]

Hi Andy. You set the ILATDC to 168 instead of 158? I've run a GB72 in a 1040 with 11.9:1 SCR (Clan) since 2010. I've used several timings having initially no data to go on. Robin Human gave me some data about 10 years ago which I took at face value: cam timing 49 71 71 49; Full lift 101 degs in & ex; total lift 352; duration 300 degs; overlap 98 degs; ILATDC 157; clearances in 10 ex 10.
I've just refreshed the 1040 and I'm running 145 ILATDC just to see how it goes. Had trouble burning off a BMW cooper S yesterday so I'm going back to 157 ILATDC! Also didn't like Robin's 10 thou valve clearances so went back to 8 in 13 ex. This will upset the Robins cam timing figures to something like 45 77 77 45 or is it the other way 53 63 63 53? A tutorial video on correct clearances and how it affects cam timing woul be useful to me at least.
Btw. I thought it's called GB 72 because of 72 degs inlet closing ABDC? Loving your content and I regret not giving you any of my engine work over the years. Mostly done by Andy Chesmam (yes I'm that old), and recently Mark Maynard.

[chrisval]

Like you, i don't like tab washers, especially in high stress situations. They are invariably made of a soft material, which causes them to collapse slightly after a few heat cycles, causing the fastener to lose it's torque.

[bwautoian]

Very interesting and educational! Question about the weld on the head between 2&3, is that corrective or preventative/strengthening?

[RTC]

Superb video and very interesting though quickly came to the limits of my understanding very rapidly 😂. Overall got the jist.
Just out of interest, have you set up an Imp engine on throttle bodies and an ECU which seems to be derigeur these days? Use of throttle bodies that is.

[catnip]

A really useful video, great camera work to capture all of the detail but I think you mis-read the dial gauge and the exhaust figure was 135 thou rather than 140 thou that you recorded.

[gothicpagan.]

GB72 Was a race profile for 850 class.

[grantfuller]

Na, you lost me describing how to find tdc . So many degrees are lost in bearing tolerance. Best way is a positive piston stopper screwed into the spark plug hole . Turn one way until it stops, turn the other way until it stops, the actual TDC is the point between these two readings .

[chrispatten]

Andy, can I be your apprentice? I can make the tea :D

[Pieterseleven]

The magnetic base for the dial: on an Aluminium engine 🙂

[lotus-e-clan]

Oh yeah... Hoping you'll do a Dyno run so I can guess what sort of numbers I might be getting out of mine.🙂