Holbay Head and Webers

[64beam]

Hi Stuart,

One other option is to go for a single side draught manifold which you see from time to time for the Hunter GT (I think) made by LYNX. One recently sold on Ebay. They have the gooseneck style offset that you were talking about. You could then install a single 45 Weber instead of twins.

Regards, Robin.

 

[Jay Laifman]

A few points on the Holbay installation:

1. The intakes on the Holbay head can be enlarged. I don't know about matching the Alpine intake size, but we matched it perfectly to the Webers.

2. The exhausts are a different story. The exhaust port is larger than the Alpine. So, on mine, I first used the SV cast manifold, and opened it up to match the head, but it still had to taper down quickly. Then on a junked Alpine I came across once, with racing stripes, it had some custom headers in the car that just happened to be the exact size for the larger Holbay ports. I got that Jetcoated and use it now.

3. On a LHD car, I removed the master and spacer, and installed a .70 Girling master. Fits fine.

4. On the LHD car steering box, what you have to do is remove the top left bolt, counter sink the plate, and use a screw with appropriate flat top and count sink sides. Then it fits fine. The bolt head hits, but the box does not.

5. I find the Holbay engine car a blast and fantastically tractable. That said, I used the F11 emulsion tubes which I find much smoother and richer running than the more common F16s. (not "richer" in gas, but richer in feel).

 

[alpine_1725]

Chaps,

The cam in the holbay engine doesn't really have a great profile - there are much better ones out there that have oodles more torque at low speed and a more linear power delivery - I got one from Kent camshafts (UK), I know cat cams (UK) also do some profiles.

hi,
I read that you've got a better cam from Kent camshafts (UK)
But if I go to their website, I can't find anything about a camshaft for a sunbeam alpine.
How did you find/got yours. Is there an alternative that you need to know to order the cam that will fit the alpine engine?

Many thanks, Thomas

 

[Dodgealpine]

Hi all, I'm running a 'standard' Holbay in my sIV, had it 4years & no trouble at all, Had it on the Rolling rd 3 years ago & by changing jetting 122bhp @ flywheel was achieved. I'm running pertronix e/i + flamethrower coil, fan removed electric one fitted. I havent needed to touch it since. If its set correct it shouldnt go out of tune for a long while.
I'm modding a 2nd head with + 0.060" inlets, inlet ports on head opened to match manifold. I'm interested in any info on this piper cam, especially one with more torque at lower revs, mines lumpy to about 2000 revs then kicks in with a vengance.



http://dodgealpine.yolasite.com

 

[ian moist]

Camshafts

From the Chrysler Hunter Workshop Manual [1972], the Holbay camshaft is tabulated as:- Inlet 58/66 and Exhaust 84/40 with an advertised lift at the cam of .320"

In Australia, camshaft grinders pale at these figures, which produces 304 degrees duration, and apparently not much pull under 3,000 rpm; yet people who have owned and driven the Hillman Hunter GLS , appear delighted with the spirited performance.

Does anyone know if strong light tubular pushrods are available in the United States for the 1725cc Alpine Motor ?

Ian Moist
Melbourne
Australia

 

[RootesRacer]

From the Chrysler Hunter Workshop Manual [1972], the Holbay camshaft is tabulated as:- Inlet 58/66 and Exhaust 84/40 with an advertised lift at the cam of .320"

In Australia, camshaft grinders pale at these figures, which produces 304 degrees duration, and apparently not much pull under 3,000 rpm; yet people who have owned and driven the Hillman Hunter GLS , appear delighted with the spirited performance.

Does anyone know if strong light tubular pushrods are available in the United States for the 1725cc Alpine Motor ?

Ian Moist
Melbourne
Australia

The reason such a large cam overlap doesnt cause low end issues is becuase the cam is well advanced and is more or less finished power wise by 5500 rpm.

BTW specs from that era were lash to lash, not the more useful duration @.050 used today. This detail makes the comparison of specs impossible to perform.

Isky cams used to sell pushrods for the rootes engine by from what I have seen of them I would not say they are durable.

 

[Jay Laifman]

But isn't the bigger issue, at least from what I learned from Jarrid years and years ago that some of the cam followers out there are really bad and don't last?