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Trent
Trent UltimaDork
8/21/24 9:34 a.m.

I built it myself, machine shop bored the block and ground the crank.

 

Being so small and simple they are a great motor to play with. No need for an engine stand, you don't have to move them with a cherry picker. Just put the block on a bench and start building.

 

I have installed one Vmaxscart supercharger.  I personally was appalled at the quality of the kit. In particular the welding of the carb mount to the supercharger case was filled with RTV and random bits of aluminum sheet. The intake manifold was very warped and would not seal. That kit took 30 hours of rework before we could install it.  The car would change lanes when you stomped on the gas though. So much torque steer.

If you want big power, call Jeremy at Jet motors and get one of his turbo motors!

 

But really, get some compression in it to match the cam, throw on a HIF44 on a good intake, a 123 distributor and a LCB header and dominate the stop light grand prix. 90hp in a mini is a blast!

 

MiniDave
MiniDave HalfDork
8/21/24 5:37 p.m.

Trent is spot on, I use those same parts and have built a bunch of nice 1275's, they are tons o fun to drive. Stay with the 3:44 final drive if all you're going to do is stay around town, the 3.0 is a great compromise of town and hiway driving.

I just got back from a Mini event in South Dakota - 130 classic Minis in the Mt.Rushmore area - and I run  2.76 final drive, so my hiway rpms are about 33-3400 at 75mph, with a 3.0 it will be around 3800. So it gives good acceleration and better hiway cruising.

While you're in there, put in a center oil pickup instead of the original - they're not expensive and you won't starve for oil in hard long turns like hitting a round about at 8/10's!  laugh

BFH_Garage
BFH_Garage Reader
8/22/24 8:05 p.m.

Thanks Dave.

What about head work? Necessary?

the PO said this one had been gone through, but I haven't had time to measure valve sizes. Pretty sure it is stockish. 

MiniDave
MiniDave HalfDork
10/16/24 4:54 p.m.

Most of the power in these motors is made in the cylinder head.......unless you're doing forced induction, then it's not quite as important. Find a copy of Visard's bible and follow it, you'll get great results!

I'm perfectly happy with the power and performance of mine using normal induction, but I did quite a bit of head work, including going with the largest intake and exhaust valve combo that would fit and not be overly shrouded - there's not a lot of room to remove metal on the outside edges of the combustion chambers to unshroud the valves as you run into the fire ring for the head gasket.....so biggest is not always best when it comes to intake valves.

BTW, I recommend the composite gaskets rather than copper ones.

BFH_Garage
BFH_Garage Reader
10/16/24 5:02 p.m.

I'm assuming you are talking about the tuning the A series book?

I've read through it and it seems to be all over the place. I was hoping for a section that said do a, b, c, d, but it isn't that clear. 

MiniDave
MiniDave HalfDork
10/16/24 6:49 p.m.

Yep, that's the one, and yes there is a LOT of stuff in that book, but if you go to the section on cylinder heads there are some pretty good diagrams to follow that show where and how much metal you can remove, and what you want it to look like when you're done.

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