Shorrock supercharged 850 engine

[mab01uk]

Interesting example of a supercharged 850 below (recently posted in an 850 tuning thread on TMF) by Oz of 'OAP Race Engines'.
He also built many of the winning Mini engines during my brothers Mini 7 racing days!

Shorrock supercharged 850, bored +087 to fit Mini Se7en Omega pistons (908cc)
515 crank
Properly modified 998 rods
OAP 265/360 cam
295 head

"Showed 90hp on KAD dyno but reduced boost and ignition to give 75hp as it was on std 3 syncro box."



OAP RACE ENGINES
7 times Mini Se7en Champions
6 times Mighty Mini Champions
http://www.theminiforum.co.uk/forums/to ... ?p=3341026

6 of the 8 Mini Se7ens featured in this video clip from 1998 (including my brother Steve) were running OAP engines.....
Epic Thruxton Last Corner
https://www.youtube.com/watch?v=xsr7yC7Yymg

[gr4h4m]

Interesting cam choice. Nice looking engine. Seems to make the power in wonder what boost they were running?

[bpirie1000]

Cracking build...

More 850 respect......

Anyone got any spare mini 850 engines?

[mini63]

Surely that belt setup is for the dyno only?

[GraemeC]

Surely that belt setup is for the dyno only?

Wouldn't have thought so, but would obviously also need the normal pump, pulley, alternator and belt putting on for the car too. The 'charger will always run off a separate belt though.

[gr4h4m]

Because there isn't a tensioner?

[mk1]

Good figures!

In fact VERY GOOD FIGURES!

I never ran any tensioner on my set up, I used the original twin belt pulleys with 2 separate v belts running side by side.

M

[emaljevan]

nice set up. but hard too find a schorrock

[mikep]

Because there isn't a tensioner?

Lot of poly V belts don't need tensioners as they are elastic and are fitted by using groove fillers on the pulleys and sliding over them. That is a standard poly V but at that length we just run them over the pulleys job done, usually OK for quite a lot of power and tend to not slip.

[mk1]

nice set up. but hard too find a schorrock.

Of all the 60'stuning mods I reckon it is far easier to find a good C75B than most other serious mods nowadays. I am constantly amazed as to how many crop up on ebay. Ok, they are an unknown quantity & can take some fitting, but at least they are still out there.

M

[johnsimister]

That could very probably be the engine that was built by Osbourne Auto Preparation for my 1959 Mini, LSK 706, the car originally restored by Perry Shaw who commisioned the engine, re-restored by me and which I sold in 2014. It looks exactly the same (although I did later fit a tensioner) and the spec is the same too. And it came with dyno figures. I hope it's still running OK.

John

[mab01uk]

Another nice 850 build from Oz of 'OAP Race Engines'.

Dec 2015
"Currently doing 850 +060 Schmidt pistons with 2cc dish, flush deck height.Thick flange block with cam bearings, modified main caps, center strapped, pocketed for 36x29 940 head. OAP 275/400 cam.Modified 515 crank.Modified 998 rods.Teflon buttons.2 x either 1 1/8 or 1 1/4 SUs.Steel flywheel and backplate.4 syncro box, starting with 3.7 cwp but ratio will be finalised after dynoing. Mate wants something fun to drive on his 10 mile country lane commute."
May 2016
Finally got it on dyno. 62hp @ 6000 rpm. 60lb torque. Power hadn't peaked but had a carb problem that couldn't be sorted at the time."



Update July 2016:
"On dyno went mega lean at around 6200 due to one of the carbs losing vacuum. This now sorted. What an absolute jewel. Drivable at low revs, but get to 2500 and the rev counter needle flies round the dial to 7500. As power hadn't peaked on dyno at 6000, all we can say it is now in excess of 62hp.
We retained the 3.7 final drive, 3.4 would be a little long, 3.6 was mentioned, but in the end we couldn't be arsed for the small gain we think it would give."
http://www.theminiforum.co.uk/forums/to ... ?p=3388494

[mab01uk]

Link below to Oz's new 'OAP Race Engines' facebook page.
Lots of old Mini photos and stuff plus a few new bits coming up.
https://www.facebook.com/ozoap/

[mk1]

Glad to see that oz is doing Minis again.

[mab01uk]

Glad to see that oz is doing Minis again.

Had a long chat with Oz in the paddock at the Brands Hatch Mini Festival about the return of OAP and him getting back into Mini's again...after he was tempted into employment by a historic race engine company for the past few years. He is currently testing the first Mini 7 engine that he has built in 12 years for my late brother Steves nephew, Ross Billison and run by Steves old team of mechanics back together once again. Next year it is twenty years since Steve won the Mini 7 championship, so its going to be an all out effort to go for it again with OAP.




http://www.theminiforum.co.uk/forums/to ... 1961-2001/

[mk1]

Thats great news Martin!

Please keep us posted on how the season progresses.

[SMOKE GREY]

Another nice 850 build from Oz of 'OAP Race Engines'.

Dec 2015
"Currently doing 850 +060 Schmidt pistons with 2cc dish, flush deck height.Thick flange block with cam bearings, modified main caps, center strapped, pocketed for 36x29 940 head. OAP 275/400 cam.Modified 515 crank.Modified 998 rods.Teflon buttons.2 x either 1 1/8 or 1 1/4 SUs.Steel flywheel and backplate.4 syncro box, starting with 3.7 cwp but ratio will be finalised after dynoing. Mate wants something fun to drive on his 10 mile country lane commute."
May 2016
Finally got it on dyno. 62hp @ 6000 rpm. 60lb torque. Power hadn't peaked but had a carb problem that couldn't be sorted at the time."



Update July 2016:
"On dyno went mega lean at around 6200 due to one of the carbs losing vacuum. This now sorted. What an absolute jewel. Drivable at low revs, but get to 2500 and the rev counter needle flies round the dial to 7500. As power hadn't peaked on dyno at 6000, all we can say it is now in excess of 62hp.
We retained the 3.7 final drive, 3.4 would be a little long, 3.6 was mentioned, but in the end we couldn't be arsed for the small gain we think it would give."
http://www.theminiforum.co.uk/forums/to ... ?p=3388494

That's Slowboys 850 engine !

[mk1]

It makes me laugh how we can even recognise our mates engines.

[1071kev]

Because there isn't a tensioner?

Lot of poly V belts don't need tensioners as they are elastic and are fitted by using groove fillers on the pulleys and sliding over them. That is a standard poly V but at that length we just run them over the pulleys job done, usually OK for quite a lot of power and tend to not slip.

Tensioner allows the belt to clear the crossmember. Other models ran without I think.

[mk1]

I didn't run a tensioner on mine & it didn't hit the crossmember.