My thoughts are below, for what their worth...I'm presuming that this will
be a street driver, so roadability is paramount.
At 12:46 PM 3/17/98 -0500, you wrote:
>Hi Listees,
>
>I've decided to rebuild my 1275 instead of buying a already rebuilt unit,
>(Thanks Skip and everyone else who helped me with that decision) So now
>I'm wondering about a few different add-on/mods and their relative value.
>
>The first is the engine rear seal from MinaMania, has anyone tried this
>and is it worth the $200? I heard it doesn't work with the 5 speed datsun
>tranny, which is fine with me as I'm rather fond of my stock tranny.
I've not tried this, but then again I've not had problems with the stock
scroll seal. For $200, i'd probably think about it, or make an equivalent.
Depends to some degree on the amount of machining required, and how much you
trust your machine shop to get it right...
>
>The second would be a high lift rocker setup, not the roller bearing type,
>but the cast MiniSpares version. Vizard gets all gushy over these in his
>book, are they worth the extra expense? I'll be putting in a slightly hot
>cam, the head is pretty stock, the carb is a Weber DGV, and the exhaust
>mainfold is a LCB header.
The cam and the rockers have to be matched to each other, so if you get a
cam designed to be used with the high lift rockers, go for it. If your
chosen cam is designed to run with stock rockers, then check out how much
lift you'll be getting, and think about valve clearance, valve spring crush,
and so on. Things to note - Plain bearing high lift rockers tend to wear
their bushings fairly quickly, and can put weird loads into the rockershafts
in some cases. We broke at least 6 rockershafts before we got the new
thickwall shafts in, and then the problem went away. I'd probably go with
the high lift, low duration type of cam setup, to keep as much low rpm
drivability as possible.
>
>I plan on all new pistons, tappets, pushrods, reground and balanced crank,
>new radiator, oil pump, water pump, bearings, and high grade bolts throughout.
>Is there anything I'm missing? (the clutch is 6 months old, so I'm leaving
>it be)
Try Omega pistons - the rings are the highest quality I've ever used. I've
never changed a pushrod that wasn't bent yet - why change them? The bolts
are a great idea - I use ARP in every thing critical, and go up 20% on the
torque specs. These bolts need to be torqued with the correct lube on the
threads and under the heads - talk to the manufacturer's tech support line,
not the distributor, if you have any questions. And speaking of
distributors, if you're going this far, why not get an Aldon type, or
equivalent, new distributor if yours is worn at all? I never have cranks
balanced - the stock balance is pretty good - but I do get new flywheels
balanced, especially if they're lightened at all.
Finally, if you're going to an aftermarket cam, you should seriously
consider an adjustable cam timing gear, and time the cam in to specs. It's
not hard, needs about $25 worth of dial indicator and magnetic stand, and
can be critical to ensuring that the engine runs the way it should. When
cams are reground, sometimes the grind requires that the lobe centers get
moved around, so the original timing is lost. The manufacturer expects that
you'll time it in correctly, and often furnishes a nice protractor to
encourage you...
If you go with new valve springs, get top caps to match, and only use steel
top caps. The pretty green aluminium ones have a bad habit of getting
nicked, and then shattering, causing dropped and bent valves, wiped out
valve seats, and pistons with holes in them. I have such a valve (1.218"
rimflow exhaust valve, to be precise) on my desk as a reminder.
That's enough for now - have fun! Brian
>
>TIA,
>
>Robert Weeks
>Durham NC
>1969 Midget
>http://www.woozy.com/midget/
>
>
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