A40 - Bloody fuck and snot!

[Matty]

Stripped the new engine this morning. It would appear I've done really well. Bores have been done and immaculate. 40 thou oversized pistons. Block is marina but crank is midget. Crank has had a regrind and again is immaculate. Conrods would appear to be Cooper S going off the AEG part codes on them. Duplex timing chain conversion. So it will go back together with new head studs, nuts and washers, core plugs, all gaskets, oil pump, water pump, stat, rings, mains and big ends. 

[Matty]

[Matty]

[Matty]

Shopping list

[Matty]

Now this is where I have an issue and need advice.

Someone has obviously spent good money on building a relatively hot 1275 here. Bear in mind this engine has come as a complete unit including a weber DCOE 40 so someone has spent money chasing a bit of power over standard. Which brings me to the cam.

It's a regrind to 731 spec. I've done some reading and it's not reviewing well as a road cam. Usual 50/50 of opinion tbf.

I am going to ring the fella who had it in his midget (and I'm pretty sure wouldn't have known it had a more aggressive cam in it) and ask how it drove.

18 in my head wants the bragging rights of a hot(ish) cam. 42 in reality can't be arsed with fuck all under 1500/2000rpm.

So what would you do? Put a standard midget grind in it? Put a fast road Kent or piper in it? I'm all ears as always kind folks!

[SiC]

Keep the cam and see how it goes? It's not as if it's not that hard to pull the engine and change it out if it's a bit too aggressive.

I'd always wonder what it was like if I didn't at least try it. Also if the carb is setup for it, you'll need to reset/rejet potentially for a different cam.

[Matty]

16 minutes ago, SiC said:

Keep the cam and see how it goes? It's not as if it's not that hard to pull the engine and change it out if it's a bit too aggressive.

I'd always wonder what it was like if I didn't at least try it. Also if the carb is setup for it, you'll need to reset/rejet potentially for a different cam.

I'll be hundred percent having the setup done by minisport on the rolling Road once the cars built. End of the day it's another hundred odd quid to have the job done right by people that build a series engines for a job. Setup should be near enough straight out of the box as all of it including the carb was in a car and being used the week before I bought it. But the experts can fine tune the setup.

I know what you mean about the cam, but I'll have to give it a dose of thinking about. I'm always time poor. So while it's not the world's biggest job, hoiking the engine back out and stripping it is a ball ache. And of course it means doing another head gasket 😁

[Asimo]

Talk to the guys who are going to tune the engine for you.

Tell them how you want it to drive and what parts are in the engine already and ask what cam you will need.

[Mr Pastry]

Standard cam in a road car IMO, it will be quite frightening enough with the right gearing.   You need flexibility and reliability in a road car, it is heavier than a Midget, and it is not easy to change cam in situ in a 1275 because you can't get to the tappets.   You won't want to take it to bits again.  Be prepared to re-jet the Weber- that said it may be alright, as it may not be set up for the 731 anyway.   Consider getting the bottom end balanced if it hasn't been done already, it is not desperately expensive and it does make a difference.   It's all looking good though.  I'm surprised that it has pressed tin rockers, not the forged type.

 

 

[Matty]

6 minutes ago, Mr Pastry said:

Standard cam in a road car IMO, it will be quite frightening enough with the right gearing.   You need flexibility and reliability in a road car, it is heavier than a Midget, and it is not easy to change cam in situ in a 1275 because you can't get to the tappets.   You won't want to take it to bits again.  Be prepared to re-jet the Weber- that said it may be alright, as it may not be set up for the 731 anyway.   Consider getting the bottom end balanced if it hasn't been done already, it is not desperately expensive and it does make a difference.   It's all looking good though.  I'm surprised that it has pressed tin rockers, not the forged type.

 

 

I was too. It seems a bit of a bitsa in some respects but good where it counts. I'm going to pinch some of the good bits off my engine. My 25D distributor is not long refurbished and full of distributor doctor parts so I'm having that. Alternator and starter motor are nearly new so I'm having them as well. 

Can I pinch the rocker assy wholesale off my 1098? Mine has forged rocker arms as it has been upgraded.

[Mr Pastry]

5 minutes ago, Matty said:

Can I pinch the rocker assy wholesale off my 1098?

AFAIK yes.  

[S2000]

I had a similar dilemma when choosing a cam for my 1043cc highly modded to go into the Wolsely, had lots of advice from various Mini forums. The best bit of advice I had was talk to Keith Calver https://www.calverst.com/ and I did, I went through what I wanted the car to drive like, the spec and he recommended a Piper 255 with solid lifters. 
Give him a call, we’ll worth his opinion.

[Scrubworks]

Give MED engineering a ring. They do their own cams and have a road cam that should be good for your needs. I was going to put one in my 1032cc but was offered an AC Dodd cam in exchange for a cylinder head I had. Kinda wish I hadn't now but eh.

[Matty]

@Scrubworks is there much on your engine build in your thread? Always interested in the intricate details of stuff like that.

[Rocket88]

A series engines are not, by nature, high revving screamers…. I’d go for a cam that’ll give as much low down torque as possible, and re jet carb to suit

[MiniMinorMk3]

I'd put a Swiftune SW5 in. The DCOE 40 is going to restrict the flow, so anything with more lift and duration would be pointless.

SW5 Billet Road Camshaft Rebuild Kit (swiftune.com)

I stuck an SW5 in a 998 and it pulled quite well  from low down.

 

By the way, I would not recommend MiniSport for the tune up. I went there once and had them do a Mini and it was horrible.

As you have a Weber you should go to someone like Motorscope, who know how to set up Webers.

Rolling Road Tuning and dyno runs in the North of England (motoscope.co.uk)

 

And finally, what size are the inlet and exhaust valves? Are they stock size or bigger?

[Matty]

2 hours ago, MiniMinorMk3 said:

finally, what size are the inlet and exhaust valves? Are they stock size or bigger?

Stock as far as I'm aware but I'll update next time I'm at the unit. I'm assuming standard but haven't measured them yet.

[Matty]

2 hours ago, MiniMinorMk3 said:

I'd put a Swiftune SW5 in. The DCOE 40 is going to restrict the flow, so anything with more lift and duration would be pointless.

SW5 Billet Road Camshaft Rebuild Kit (swiftune.com)

I stuck an SW5 in a 998 and it pulled quite well  from low down.

 

By the way, I would not recommend MiniSport for the tune up. I went there once and had them do a Mini and it was horrible.

As you have a Weber you should go to someone like Motorscope, who know how to set up Webers.

Rolling Road Tuning and dyno runs in the North of England (motoscope.co.uk)

 

And finally, what size are the inlet and exhaust valves? Are they stock size or bigger?

Shame about minisport. They set up the 1098 in mine (hs4, 295 head, maniflow) and its excellent. Agree on the Weber knowledge though.

[Matty]

Engine was still in bits at the unit, but I'm going to build it in work cos better facilities. So this week I decided to start on a bit I had at home.

[Matty]

Manky as fuck. Purchased a rebuild kit, new top screws and an air filter backing plate gasket. And set to.

[Matty]

Getting cleaner. I removed all the jets, emulsion tubes and venturis and soaked them whilst I cleaned the casing and it's passageways out. There was old petrol varnish everywhere.

Made sure to take all the details whilst I was in there so whoever gets the job of rolling roading it knows the starting point.

[Matty]

Checked the float still floats and rebuilt. Filter cleaned and oiled, a shit load of polishing and I reckon it's come up alright. Nice things to work on DCOEs tbh.

[Matty]

Next installment will be a rebuilt head. With new valve guides and seals. When I get round to rebuilding it. Possibly next week 🤣

[MiniMinorMk3]

Did you fit any ram pipes on the carb inlets? If you do not fit any then the turbulence of the right-angled inlet will cause a restriction in airflow. The smallest you can get are 16mm deep, so they should fit in your filter.

Weber 40 DCOE Slot In Trumpets Various Lengths from 16mm to 75mm (weber-carbs.co.uk)

Ram pipe Weber 40DCOE 16mm superlight aluminium (burtonpower.com)

Also, what have you got between the carb and manifold. Some advise that you should put sandwich plates in to help with the damping vibrations that can cause problems in the float chambers.

Misab Plates Weber and Dellorto Manifold to Carb Mounting (weber-carbs.co.uk)

Sandwich plates, Misab, 40/45/48DCOE x 2 (set of 4) (burtonpower.com)

[Matty]

25 minutes ago, MiniMinorMk3 said:

Did you fit any ram pipes on the carb inlets? If you do not fit any then the turbulence of the right-angled inlet will cause a restriction in airflow. The smallest you can get are 16mm deep, so they should fit in your filter.

Weber 40 DCOE Slot In Trumpets Various Lengths from 16mm to 75mm (weber-carbs.co.uk)

Ram pipe Weber 40DCOE 16mm superlight aluminium (burtonpower.com)

Also, what have you got between the carb and manifold. Some advise that you should put sandwich plates in to help with the damping vibrations that can cause problems in the float chambers.

Misab Plates Weber and Dellorto Manifold to Carb Mounting (weber-carbs.co.uk)

Sandwich plates, Misab, 40/45/48DCOE x 2 (set of 4) (burtonpower.com)

Thanks for the info. Well worth considering. Although it's an extra expense, it will pay to do the job properly. 

I was already aware of fuel turbulence problems. I have made up two viton  orings that sit between the carb and the inlet manifold. Do you think that will be sufficient?

[N Dentressangle]

Having read the reviews I think I'd give that cam a try. If you want a clockwork idle and smooth low-end power, you know that you'd be better off with something closer to stock, but if some performance is what you fancy then it sounds worth a go.

DCOE's in my experience are mighty thirsty, so you may as well try and get some more power for all that extra fuel! If you go back to a stock cam, you may as well re-fit an SU HS4 or similar and save money on E5.

[Matty]

4 minutes ago, N Dentressangle said:

Having read the reviews I think I'd give that cam a try. If you want a clockwork idle and smooth low-end power, you know that you'd be better off with something closer to stock, but if some performance is what you fancy then it sounds worth a go.

DCOE's in my experience are mighty thirsty, so you may as well try and get some more power for all that extra fuel! If you go back to a stock cam, you may as well re-fit an SU HS4 or similar and save money on E5.

I'm going for it because if I don't ill always wonder! If I don't get on with it then changing the cam gives me something to do next winter 😄

[N Dentressangle]

That's the spirit!

That cam sounds OK, actually. Just like most 'hot' cams I've ever experienced. Don't get something for nothing 😉

[Matty]

4 minutes ago, N Dentressangle said:

That's the spirit!

That cam sounds OK, actually. Just like most 'hot' cams I've ever experienced. Don't get something for nothing 😉

When you do a bit of reading, you find loads of people (including David Vizzard) who say the 731 grind is a load of shite. And one or two who say they are sound. Obvs I'm only listening to the one or two 🤣

[Matty]

By the way, everyone who advised on what cam to use, genuinely grateful. I am however limited by budget, I already own this one, so I'm giving it a go. If its awful, more time will have passed which gives me the opportunity to make more wage and buy a better one!