Should I run a camshaft from the 1955 Crowfoot Holden?

[Thommo]

This is really coming together for you
Nice score

[GreyEJ]

Sounds nice. You'll have to let us know how it goes. What about a few pics of the ports before you bolt it together?

[Stygian]

Sounds nice. You'll have to let us know how it goes. What about a few pics of the ports before you bolt it together?

Sure. Next time I'm around at Eric's (possibly this Sunday) I'll take a few iPhone pics. I'll see if I can get a shot of my standard grey head next to it.
I believe the head has been worked to match the cam and it looks like the porting has been done very well (as you would expect in a race prepared head). I'm hoping the whole head/cam/high compression piston combo works well together.

[STANLEY]

This engine will be an absolute pig to drive, no low rpm throttle response & by the time it comes into the power/torque range it will be way up in the rev range.
I love the thought of a stinking hot grey or red six, but I can tell you after owning & driving these types of engines it will be $*#@ horrible as a street car.

Big cams, big heads, triples & large diameter pipes all move the power further up the rev range not create more power where you need it.
Think also of the diff gears reqd. to make this combo work, what diameter tyres will you run with it???
Too tall & the thing wont pull away from a set of lights properly let alone on a hill start.

[Stygian]

Hello Stanley, thankyou for your comments. I shared similar reservations to the ones you have expressed; and I originally planned to build something much milder.

However, I was privileged enough to drive Thommo's FB around the streets of Narrandera during the previous Nationals. The hot grey in his car has VERY similar specifications to the engine Eric is building me. Big head (ported, 179 valves), big cam (35/75), a relatively low 8.6:1 compression ratio and triple Strombergs. Given these specifications, I honestly thought (as probably you would) that his car would be difficult to drive down low.

But I was pleasantly surprised and very impressed with how tractable and well mannered his car was at low speeds. It compelled me to do alot more homework on hopping up an engine.

With respect to the triple Strombergs, following Thommo's example mine have been professionally rebuilt, fitted with venturi sleeves and smaller main jets. Smaller venturi size assists with low down torque and tractability. Bolting on a set of tired old Strombergs with worn out throttle butterfly shafts, stock main jets and without venturi sleeves (like some people do) will guarantee the engine will perform very poorly at low speeds.

In regards to the Wade 140 cam, I spoke to Wade Cam's technical expert and point blank asked him "Is this a streetable grind?" He replied that it was contingent on three factors. Firstly, that the static compression ratio be raised to 10.5:1 (the stock grey motor compression ratio is a low 7.5:1). Using a high performance cam without increasing the static compression ratio (to offset the loss of dynamic compression due to the intake valve closing later) will definately cause an engine to produce LESS power than stock and be horrible to drive around town. Secondly, that the car was not a daily driver. Obviously a big cam makes for an annoying daily driver, and my car will be strictly a weekend only vehicle. Thirdly, that adequate carburetion was employed. I said I was using triple Strombergs and he replied that this was suitable.

With respect to the exhaust, I will be using Jack Myers headers, which were designed to be used with a single 2 inch system. Running a twin system right to the end of the car, like some have done with these headers, will cause the engine to produce poor amounts of power down low.

In regards to the diff size, I will use a 3.55 ratio. I have found that most cam manufacturers recommend using a 3.5+ diff when the grind is bigger than 225 @ 50 thou. The rolling diameter of the tyres will be around 24 inches, which was the stock rolling diameter for FBs and EKs.

I will also regraph the distributor and install the Pertronix electronic ignition kit. This will also assist the behaviour of the engine down low.

But in the end, if the car IS a pig to drive, then I will simply get my stock cam reground to Wade 446B or 240 specification, and install that. It doesn't bother me if that is how things turn out.

[STANLEY]

Like I said, been there & done it.
Horrible to live with on the street & no real hp to brag about either.

Hope it does see the road because a hot grey is a wonderful thing to hear getting thrashed.
BTW - 10.5 in a grey will be very marginal for detonation because of the shitty chamber design, maybe your new head has this addressed or another phone call to the technical dept. is in order???

Thanks for the lessons in engine building, wouldn't have a clue what to do otherwise

[Stygian]

I wasn't being smart. I was merely explaining why I have made the choices I have.

Actually, the head has been previously used with 12.5:1 compression, so I believe the chamber design issue has been addressed.

Like I said, if it turns out to be a pig, I will change the camshaft to a milder one. Quite simple really Stanley.

[STANLEY]

Not a chance a grey will run 12.5 on pump gas.

[Stygian]

You're absolutely right and I would not run a compression ratio that high. Thanks for your concerns Stanley.

[GreyEJ]

It might not be that easy to drive but it sure will soudn nice. Check this one out.

http://www.youtube.com/watch?v=zqt-8yg12Q8

[parisian62]

Hi GreyFC

That's Thommos grey, mentioned in this thread, that Andrew (Stygian) videod and drove at the Narrandera Nats. I had a drive too and found it very easy to drive.

Here's another video http://www.youtube.com/watch?v=EcejlMjyxZE Check out at 5.10 for some more grey action...

Stewart

[GreyEJ]

I love it! Nice work Tommo

[Thommo]

I love it! Nice work Tommo

Thanks GreyFc

Styg, your car will run just fine, you have done all the homework possable
and it will pay off.

Just keep a set of 3.9/1 diff gears handy, 3.55's are the lower limit of the prefered.
I would change them before changing the cam.
You wont need to change the cam anyway though.

Cheers
Jeff

[Stygian]

Cheers Jeff . Eric's built more stock, street performance and circuit racing engines than most people on this forum have had hot dinners, so he wouldn't build me something that wasn't driveable.

Yeah, changing the diff is a damn sight easier than changing the cam when the engine's in the car (I've done both before). I'll keep a 3.89 centre handy.

GreyFC, here is a video of Jeff (Thommo) taking myself, Stewart (parisian62) and Rob (fbcrusin) for a spin around Narrandera in his hot grey powered FB http://www.youtube.com/watch?v=QI9-rfC38Pk

As you can see, it pretty much proves that a hot grey motor with a big cam can be very well behaved around town, provided that it is set up properly.

[Thommo]

GreyFC, here is a video of Jeff (Thommo) taking myself, Stewart (parisian62) and Rob (fbcrusin) for a spin around Narrandera in his hot grey powered FB http://www.youtube.com/watch?v=QI9-rfC38Pk

Bloody squeeeeeeeky clutch pedal