SA1100 build recommendations

[mk1]

Rich is known as Mr SA1100 , he's ya man on these engines .

I taught him everything he knows

[mk1]

The rods I referred to are indeed the ones from Maxpeeding rods. Available on ebay for F*** all.

I doubt I'd use them in a competition engine, but for normal road stuff I certainly haven't had any issues.

[goff]

Rich is known as Mr SA1100 , he's ya man on these engines .

I taught him everything he knows

,Mark you can be Mrs SA1100

[mk1]

OK, Sounds fair enough.

[Pandora]

This is why we need Rich back.

Al

[goff]

Timmy201 Regarding the SA engine ,i forgot to say, if you go down the route of using standard length rods and having the top of the blocked decked you will need to use small bore pushrods and head studs , hope this helps'

Goff

[LuisM]

Timmy201 Regarding the SA engine ,i forgot to say, if you go down the route of using standard length rods and having the top of the blocked decked you will need to use small bore pushrods and head studs , hope this helps'

Useful info, thanks Goff.

in the past i had been looking at piston options for large overbores ( ~ 73mm ), there might be some pistons from japanese engines ( MAzda, Mitsubishi, Datsun ) that might suit....

anyone here has used them by chance ? maybe some are a bit taller and no need to heavily deck the top of the block.

Thanks
Luis

[almondgreen]

What are small bore head studs?

[Spider]

Useful info, thanks Goff.

in the past i had been looking at piston options for large overbores ( ~ 73mm ), there might be some pistons from japanese engines ( MAzda, Mitsubishi, Datsun ) that might suit....

anyone here has used them by chance ? maybe some are a bit taller and no need to heavily deck the top of the block.

Thanks
Luis

Hey Luis, Mazda and Honda Jazz Pistons are available in those sizes, I can look a little later at the Pin to Crown Heights but I'm sure they are all lower than A Series.

[timmy201]

Timmy201 Regarding the SA engine ,i forgot to say, if you go down the route of using standard length rods and having the top of the blocked decked you will need to use small bore pushrods and head studs , hope this helps'

Goff

Thanks Goff, I did remember reading about the small bore pushrods on one of the older posts here. I haven't seen any small bore specific head studs? I would assume if I bought the same ones that fitted my 1098 I'd be OK

Useful info, thanks Goff.

in the past i had been looking at piston options for large overbores ( ~ 73mm ), there might be some pistons from japanese engines ( MAzda, Mitsubishi, Datsun ) that might suit....

anyone here has used them by chance ? maybe some are a bit taller and no need to heavily deck the top of the block.

Thanks
Luis

I have looked at all the options - longer rods, taller pistons and decking the block. I have come to decide that decking the block would be best for me. It is a one time operation for machining and then it allows you to use standard parts - rods, pistons, pushrods etc

Hey Luis, Mazda and Honda Jazz Pistons are available in those sizes, I can look a little later at the Pin to Crown Heights but I'm sure they are all lower than A Series.

I have done a little searching and can't find anything near enough to work - you might have more luck though. Then a secondary problem might be the gudgeon pin diameter is different and needs to be corrected.

[goff]

What are small bore head studs?

What are small bore head studs , almondgreen I found out that after fitting the 1300 studs that came with the engine ,when i fitted the head the studs they were to long !!!! , if you think about it the block has had aprox 6mm machine from the top ( decked ) , so the head would sit 6mm lower than the studs , the studs ran out of thread and started to bottom out , i have a couple of 1100 engines , so i removed the studs and found they shorter , i learned the hard way by fitting the studs , gasket ,rockers , head and then tried to tighten everything up !!! , you learn something everyday , if you have a die you could run it down a bit , BUT they are high tensile or maybe a machine shop could do it for you '

photo attached showing studs difference ,

hope this helps

Goff

[LuisM]

Hey Luis, Mazda and Honda Jazz Pistons are available in those sizes, I can look a little later at the Pin to Crown Heights but I'm sure they are all lower than A Series.

Hey Chris,
did some searching and came up with some Mitsubishi 4G36 engine pistons , 73mm bore and 39.5mm compression height..1.5mm than the mini ones.

http://www.totopiston.co.jp/cat/piston/toto11ma-1.pdf

if i get one of these cranks, i'll check further these pistons.

Cheers
Luis

[Spider]

Hey Luis, Mazda and Honda Jazz Pistons are available in those sizes, I can look a little later at the Pin to Crown Heights but I'm sure they are all lower than A Series.

Hey Chris,
did some searching and came up with some Mitsubishi 4G36 engine pistons , 73mm bore and 39.5mm compression height..1.5mm than the mini ones.

http://www.totopiston.co.jp/cat/piston/toto11ma-1.pdf

if i get one of these cranks, i'll check further these pistons.

Cheers
Luis

Cheers Luis,

The SA 1100 - as best I can find out - has a nominal stroke of 2.75" and the 1275 engines a stroke of 3.00".

In order to use a fairly unmolested 1275 block for a SA 1100 build, the Pin to Crown heights would actually need to be 1/8" (3.175 mm) or there abouts higher. Therefore, according to my rough numbers here, the Pin to Crown height ideally needs to be in the region of 41.15 mm. None the less, at a height of 39.5, that's very much worth considering.

[timmy201]

I think you should have 3.2" stroke for a 1275?

So the amount off the top is 0.225" or 5.7mm

[Spider]

I think you should have 3.2" stroke for a 1275?

So the amount off the top is 0.225" or 5.7mm

Ha !

Yes !!

Or 1/4" added to the Pin to Crown heights

[mk1]

Without putting too fine a point on it. Using tall pistons is just daft. The whole idea of these engines is to me a free revving unit. Sticking daft great heavy pistons in it is a seriously retrograde step.

[251 ENG]

Mark is correct about pistons compression heights

BUT

If anyone wants to build one of these engines ,s we have some +20 omega forgings with increased crown height that could be available at a very reasonable price

[Spider]

Without putting too fine a point on it. Using tall pistons is just daft. The whole idea of these engines is to me a free revving unit. Sticking daft great heavy pistons in it is a seriously retrograde step.

Absolutely !

That's why the 'trend' with most modern engine design has been to lower this height and why there's nothing in the Japanese Engine Range that fits this bill.

[gr4h4m]

I run a SA crank, bored plus 40, using calver pistons and a set of longer H beam rods with the correct size for the crank journal, to save chopping the block. I used Williams rods, the bloke peddling them is not far down the road in north wales. He was very good to deal with. I met a mini 7 racer that runs them to 9600. My cars rev limiter is current set at 8300, it gets there very quickly and makes great power.
The engine tuned out better that I thought it would, it’s fantastic and I love it.

[timmy201]

I run a SA crank, bored plus 40, using calver pistons and a set of longer H beam rods with the correct size for the crank journal, to save chopping the block. I used Williams rods, the bloke peddling them is not far down the road in north wales. He was very good to deal with. I met a mini 7 racer that runs them to 9600. My cars rev limiter is current set at 8300, it gets there very quickly and makes great power.
The engine tuned out better that I thought it would, it’s fantastic and I love it.

Thanks Graham, what cam are you using out of interest? Good to hear you like this style of engine

Edit: I’ve remembered I’d already read about your engine build on turbo minis and you had a supercharger. I’ll have a read up to see how you went