MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - rods and flywheel

So next bit under scrutiny for my new engine build.

My spare block was completely std.

So was the flywheel but the surface is pitted due to bad storage.

So to bring it up to scratch i need to have it:
lightened
resurfaced
drilled for a 7.5"clutch
fit a new starter ring

But add that all up and you come verry close to a steel Peter May flywheel....
Any other options?

Then my rods again bog std.
But that is not the problem.
Again due to the bad storage I've had to use a lot of force to remove one piston and rod from the block.
Now i do not really trust that rod any more.

I know i can get it checked for straightness and big end roundness and crack tested.
But does that really say it won't come apart at 7000rpm?
Onno Könemann

Hi Onno

If you haven't dented the rod battering it out I think you should be ok. The rods are really high quality, we have never had one let go or a rod bolt go. I suggest you check the rod bolt threads for necking and fit new nuts.....as for the flywheel, you cannot lighten it much to fit the larger clutch. You will have to weigh up the difference in cost, mind you a nice shiny new flywheel does look good :)

Peter
P Burgess

Rod bolts will be replaced so they are no problem.
New fly wheel is something like 50 quid more than the machining so that is starting to look very good.
Has any one got a see through ribcase housing so i can still see it ;)
Onno Könemann

Dont forget a perspex bonnet and dizzy cap :)

Peter
P Burgess

Onno

Careful with the lightened flywheel

On the all aluminum fredinsa fly it dosnt like mods vary well... If you remeber I spent about 3 months trying to make it properly talk to everything else... then agian it does only weigh in at 7 lbs... and yes its advertised as a direct fit...Definatly Needs more fine print in the adverts

In the end, I pretty much love it, but you have to learn to drive all over agian.

super easy to stall, dosnt like steep long hills much, and needs clutch and gas peddle feathering from every start off from a stand still.

http://www.dragcars.com/parts/FIDANZA-ALUMINUM-FLYWHEEL-MG-midget-MG-Sprite-1275-66-For-Sale_120325290504.html

OR

http://thmotorsports.com/fidanza/fidanza_flywheel_aluminum/126751/i-264809.aspx?googlebase=126751-03-1972

OR

Ebay number... 120325290504
Prop

Prop
I remeberd the trouble you had so kind of was ignoring the Fidenza ;)

As you might remember my 1380 has a lightend flywheel.
So i am used to how it drives (though the Fidenza may be lighter)

But i do not want to use that as i want to drive my midget in the shop change the engine and be out in a day.
Plus that would need machining for the bigger clutch and the ring gear is not great.

PM has a steel flywheel that look right for the job.
http://www.petermayengineering.com/specialistProducts.htm#7.58.1
Would go for the F3 flywheel ;P if the clutch cover was not so damn expensive!
Onno Könemann

I understand where your comming from.. its a good plan, I know phil burke is doing similar by gettng a spare fly done in advance to fit the new style datsun 5 speed conversion he is starting to install tomarrow.

I wish I was there...and Im sure he is glad im not.

LOL.

Prop
Prop

I have one of Peter Mays's lightweight steel flywheel for a 7.5" clutch (Ford plate). It looks more like the photo of the 7.25 cover than the 7.5 cover on his website. It weighted less than my old lightweight steel cover and that weight reduction was towards the outer part of the flywheel where it matters most.

You'll get something for a stock unmolested 1275 flywheel to close the price gap!
Daniel Thirteen-Twelve

That's it i'm sold ;)

More good news
Was bussy with the burette yesterday and measured my "fastest" head at 18.7 CC
And with +020 pistons with a 6CC dish I am in for a 11.5:1 CR
High but not to high as it will be running a cam in the 280 to 290 range.
Not completely sure on that one yet in doubt between an RE13 and soem MED cams.
The MED cams come with the added benifit of bing cross drilled on the lobes........
Onno Könemann

I too have the P.M. steel flywheel with 7.5 Ford clutch and all I can tell you it is one of my favourite engine mods I have made, the difference of before and after is very noticable, it feels alot more responsive and revs like a 2 stroke bike engine (well nearly, Iam getting carried away now)
Go for it Onno, you know it the right thing to do !!


Rob Newt

Ohh heck YES!!!

Thats got to be a good 30% lighter...Like danial says... all the meat is off around the outside edge where it counts... Love it when a plan comes togather
Prop

Funny,
I just took my FW off 2 minutes ago.
BillM has sent me a FW thats been drilled and tapped for his particular Datsun conversion. I'll give him mine at Midget 50

I was just thinking about lightening. Last time I had it out, I was talked out of it for all the reasons Prop mentioned.

What would a mild machining do for a fast road engine?
Phil Burke

Hi Onno

All the Piper billet cams come with drilled lobes, I should think the billet Kent ones do as well. Piper will happily grind any profile. We tend to stock the ever popular 266/76/86 ones as most A series owners will easily be able to find out what each cam can offer them.

If you are going for it, the STR930 profile which Piper grind exactly to the Milia specs works very well,I know Mike Garton worked with both Piper and AR to ensure it is a perfect copy of the profile. I am lead to believe it is an update of the old 649 cam but to match silenced exhausts. It is hairier than the 286 though, coming in strong at 3250 rather than the 2650 of the 286. We have the choice of either the 930 or 286 in one class of Metro racing....the 930 wins hands down, as with the 286, it thrives on high CR.

Peter
P Burgess

The STR930 sounds nice but...

This is going to be long so i'd better start an other thread...
Onno Könemann

Go one Onno......do tell

Peter
P Burgess

This thread was discussed between 20/02/2011 and 22/02/2011

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.