Hi all I am new here and am just after some advice on putting a turbo on my 1460 it has a 74 mm of set bore.
I have found a lot on 1200 and 1300 turbos but nothing on big bore engines as I am worried about the wall thickness being a bit thin.

The motor is out for a bit of a freshen up and I was thinking a turbo or 7 port cross flow would be good and as I have some turbo bits I am leaning more to the turbo but the look of the cross flow is cool as well.I was looking at the US alloy 7 port heads from Pierce Manifolds any reports on them as well would be good

It is in an 850 with straight cut box and LSD diff.

Thanks in advance

Garth

there are certainly quite a few guys in the uk running 1380's with turbo's at significant boost (15-20psi) blow by does not seem to be a problem.

I myself have a 1380 turbo with a minisport 7 port head with efi.

Which head gasket are you running?

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1970 Mini Deluxe - 1275, Weber, Clive 346 cam, MS 4-pot slotted discs, Megajolt ignition Now with new improved Mambas... almost on the road
1966 Van with Traveller rear seat conversion
2008 Prado GXL
All in various states of repair...

on my "trial" engine i ran two bk 450's to get the compression down,

when I put the current engine in with bigger dishes in the pistons I went to one Bk450, but due to the dodgy batch it currently has a Cometic on there.

Now the 450's are ok again i'll revert to one of them next tim the head is off.

Seen your build on turbo minis with much interest, big thumbs up.
Do you get paint blistering of the paint on the bonnet with the turbo there?

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1970 Mini Deluxe - 1275, Weber, Clive 346 cam, MS 4-pot slotted discs, Megajolt ignition Now with new improved Mambas... almost on the road
1966 Van with Traveller rear seat conversion
2008 Prado GXL
All in various states of repair...

Ohh Ohh more questions. You've had this build completed for a while now. Any learnings, things you' d do differently?

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1970 Mini Deluxe - 1275, Weber, Clive 346 cam, MS 4-pot slotted discs, Megajolt ignition Now with new improved Mambas... almost on the road
1966 Van with Traveller rear seat conversion
2008 Prado GXL
All in various states of repair...

cheers

I've not had any probs with the paint yet, at the start of the sumer when i put the new lump in iI raised the back of the bonnet just in case, but it ran for 6 months with the turbo about 1 1/2" below the bonnet with no flaking/ discoloration.

there is a few things i would do differently, mainly wiring and not engine wise, but I should have used bmw piston oil jets rather than the ford ones,

back when i started this there was no BMW head conversion kit, if it had been i probably would have gone that route. also the elder heads wouldnt really have been in my budget with shipping.

another head that would have been easy to stick on would be a 1.2 fiat 8v head.

boost isnt so good on the bigger capacity engines, the cyl wall thickness isnt great on an N/A engine, and the boost just makes gasket problems between the cyls even worse

its really not as much or a problem as its made out to be,

When you're building an engine like this for the road do you really need straight cut drop gears? I'd want a relaible power train (as reliable as it can be in a force fed big bore) but would prefer to avoid the noise of teh striaght cut drops.

hmm depends what kind of power you want to put through it, and how you're going to drive it.

i am running a standard helical remote change box with a comp layshaft and diff pin on my supercharged 1360.

i also wanted to avoid the noise of straight cuts.

an A+ box is stronger so might be a better choice if you want to keep the helical gears.

tbh i dont find the noise that bad, in fact my missus will quite happily go to sleep in it on the motorway at about 70mph. mind you thats with a 3.1 diff...

Just buy some headphones, or a load of dynamat for the bulkhead. Cheaper to go with something that wont break than risk one hard start destroying a gearbox.
And it adds to whole animal feel, i would love to have a big bore a series at flat chat with boost and straight cuts.

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Simplify and add lightness

I wouldn't bother with straight cuts for what you want - they aren't stronger, they just consume less power. Straight cut drop gears are the main culprit of the noise (which is no bad noise if you ask me )

ah,

the age old S/C vs helical debate!

While I agree that helical gears are stronger for the same material, are aftermarket gears not made of better stuff?

for turbo use the helical stuff starts breaking around 140hp, less if your a hooligan! more if you my gran, the minispares kit seems happy to around 200 hp,


anyway, side loadings are what we need to combat.