Do you remember

[jlaird]

the discussion we had long ago about Stage I,II,III, and IV engines when I said I had a stage four.

Well while I was at Tonys my nice wife found my copy of Austin-Healey Sprite Special Tuneing from The Austin Motor Co. LTD. Longbridge, Birmingham, Box 41 G. P.O., Part number AKD1821A.

In side it talks about Tuneing Condition 1 thru 4 and gives all the specks to meet each condition. Condition 4 works out to 50 HP up from 42 stock.

Compression up to 9,3:1 with flat top pistons. Grind and polish exhaust ports out to a small form that they provide and I have. Heavy valve springs. Camshaft. Carbs with GG needles. Dizzy 2A951 and lighten flywheel to specs provided.
Gives 52HP at 7000 RPM. I had a few more tweeks such as H2 carbs and all ballanced to a 1/2 gram. Mine would quit at 7300 RPM I I suggest was pulling about 55 HP.

Any who, I though you all might find that intresting.

 

[GB1]

Jack

Thanks for sharing, but I suspect that a non factory stage four engines would be puttin out a heck more bhp.

Patrick

 

[jlaird]

Noop. That's what the book from the factory says.

 

[DrEntropy]

Considering 42 HP as a "starting point" that's better'n 20% increase, Patrick!! I'd say that's kinda impressive, actually.

 

[GB1]

Doc

Yes it is impressive, but I would venture that a present stage four 948 engine would be close to 90.

If a 1275 bored to 1330 can pump out 120+ then I would venture a 948 bored to 998 could pop out 90.

BTW my Stage 2 1275 is in the 90+ range up from 64 that is 20% more at stage two. Granted it is easier to get power out of a 1275 the 948.

I am just pointing out that the factory stage four is probably a stage two by modern standards.

All the above is IMHO, since "I am not a doctor nor due I play on TV". /ubbthreads/images/graemlins/devilgrin.gif
Patrick

 

[aeronca65t]

For those of you interested in the BMC Special Tuning manuals (including 948), you can find them here

(brought to you free from my pal Steve, here in Good Old New Jersey /ubbthreads/images/graemlins/jester.gif ):

https://www.1978mgmidget.com/manuals_and_booklets.html

 

[Baz]

7:60 GBP for a lightened flywheel
85:00 GBP for a large valve race head
Ohhhh the humanity.

 

[jlaird]

Hmm, mine is different than what he has.

Have him send me an email with his address and I will drop a copy in the mail for him.

 

[Bugeye58]

Patrick, my .040" over 948 dynoed at 91.2 HP @ 7400 RPM.
Jeff

 

[jlaird]

Jeff, I want one. Over.........

 

[Bugeye58]

It wouldn't be worth squat on the street, Jack. It doesn't start to make any power until 5000 RPM.
Not to mention rather pricey.
Jeff

 

[jlaird]

Hmm, I could feel and hear mine step up on the cam at about 2700 and pulled hard to 7300 where it gave up, hehe.

Wonder where I got that cam and what it was. Bought new from a cam company in Atlanta. No clue what the specs were or how I even convayed to them what I was after.

 

[Bugeye58]

This thing of mine is pretty radical, for a somewhat reliable 948. Billet crank, Carillos, etc. It was built for me by Huffaker.
Jeff

 

[jlaird]

Ahhhhh, now all this time I thought you built it.

We will find a head for this one, along with a cam and a lightened flywheel and H2 carbs. With the 998 cc bore it should pep up a bit.

I'm sure it would still be streetable as the previous one the wife drove to the store and shoping and such.

 

[Bugeye58]

Jack, it's the only engine I've got that I <u>didn't</u> build myself. Long, boring story as to why this one was built for me.
Jeff

 

[GB1]

Jeff,

just putting out some rough numbers for Jack and Co., A bit conservative albiet, but something.

I can't believe how my stage 2 1275 screams!

Patrick

 

[DrEntropy]

Thank you and your friend, Nial! I'd had a copy of the control box manual, seems like it's been eaten by a naked singularity... the other three inna top row I have relocated.

Thankyou, Thankyou! /ubbthreads/images/graemlins/savewave.gif

 

[jlaird]

You guys do know those manuals can be copied to your machine, all but one anyway.