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So the motor I have just put in my sigma (astron 2.6) has just done a bottom end and I have been reading and reading but I need someone to just lay it out straight for me... I wanna put a magna head and bigger pistons stuff like that along with the efi and probably end up a turbo in there somewhere... So my question is, is the tr the right path to go down? I was just gonna buy a whole car and use what I need and scrap the rest some ideas and advice would he sweet cheers

So the question is whether a TR Magna will have the larger ported head and whether it can have a larger piston diameter piston fitted?

Provided you get an EFI TR and it has a m6-m8 head then yes. I recommend a cheap donor. Get one thats cheap (300 is what i paid) but not one with severe engine mechanical problems. You can get larger diameter pistons and someone with more knowledge then i have can tell you how much 'over thou' you can go. I wouldn't bother with the factory ecu but some people would. I found that having a computer that will talk to you is a lot easier and if you do want to go turbo you may as well do that as its a mod that will be useful even without a turbo. If your looking at doing a full build get your block and head pressure tested. The blocks and heads can crack particularly if like in my case you get one that has a very rusty coolant system. The TR head should fit to any Astron 2 block. I would and did choose a TR over TP as its more modern and has in my opinion a much easier to work with inlet.

your better off doing a TP magna conversion because the efi unit sits lower, i have a TR head conversion on my magna and the efi unit had to be shaved down because it put a big dint in my bonnet.

shit.. i meant sigma not magna

TR block, TR head and TN EFI is what I put in the LC
GJ block, TN head and TN EFI for the GA

Both stock, both 'feel' similar, although gearing. weight etc is much different, so it's hard to compare directly.

GJ block is easier than the TR block - nothing "major", just little things.

cheers
gaz

Will also depend what gearbox you want to run as to what block you run.
If you want a wideblock gearbox then you will need a wide sigma/scorpion block. (factory manual blocks...these are generally stronger gearboxes, can also use Starion gearboxes)
If you want a narrow block gearbox (4 speed or narrow 5) then magna block or narrow sigma/scorpion block is fine. (factory auto blocks)
Wouldnt run an M8 head unless you have the pistons to go with it or your compression will be a lot higher due to the decrease in combustion chamber size.
M6/M7 are pretty much identical.
If its in a Sigma use a TR/TS intake manifold as they are a lot longer and you will get more torque as well as a larger throttle body for that turbo later.
If turbo now then use aftermarket computer, if turbo later standard computer can be rewired to suit application, however with mucking around its almost worth getting aftermarket and simply re tuning when turbo comes. I have stock computer in my rally car and it ran fine, but I have no turbo.

Hope this helps.