Hi,
I'll bet you got other responses... hopefully there's nothing new here.
But, what the heck.
If you add DCOE 40's to a TR6 and then add:
Header - this is a must. Free-flow exhaust helps too. Do you like to talk
to your passenger when driving? If so - use caution with what you select
for a free flow exhaust. Net HP gain - not too much.
Electronic ignition - this is a must. You won't be able to get the car to
run very well without it. At a min. use the Crane $100 unit. For more
spark, try the Hi-6 or whatever it's called. Net HP gain - not too much. If
you want true total tunability - then go for the Electromotive unit. That's
not very streetable, though.
Port Match - this is most def. worthwhile. I think I got something like 10%
increase in airflow on my car. Really.
Air Cleaner/Air Box - you should do this. Cold/cooler air is better for
combustion. Plus you won't get wierd vapor lock or gas boil over in the
carbs. Net HP gain - not much but you will get more reliability.
At this point, you're talking about 120/125 HP with the stock cam. We're
assuming you have a "federal US spec" cam here.
Now - spend some real money.
First, drop the fan and put in an electric. Net gain, about 6 - 8 HP.
Pull the motor and yank out the crank. Get the thing dynamically balanced.
Get the journals micro polished. Check the rods and balance/recondition.
Got some extra cash? Bore that baby out to .030 or .040 over. Assemble,
measure and take apart - get block "decked". You now have "reference" to
calculate the total size of the combustion chamber. Once you reassemble,
you'll have gained a little bit of HP because of the balance - but you're
ready to build some power.
You've now laid out about $2k, more or less. Maybe a bit more.
Now, take the head to a good head shop. If they don't know what a TR6 is,
go elsewhere. And as you may have guessed - we're now ready to free some HP
from your motor. Get the head crack checked - no sense doing any work on
this puppy if its cracked!
Next step - mill the head. Go to no more then 9.5 : 1 for a streetable
motor. Unless you have a fuel truck that can chase you around with some
Avgas to refill from. You might be able to get away with 10:1, but if you
aren't careful about where you fill up, you'll be sorry!
This will net you some HP, maybe another 10 or so.
Now you need a cam. The PI cam is something like .340 lift at the valve and
290 degrees of duration. With this setup, you're talking about 150 HP.
There's a lot of grinds available that give more like .400 lift (the S2 or
the Isky X19 grinds, for example) that don't go into the lumpy idle range
of above 290 duration.
Need more?
Get the valves ground with a three angle valve grind. You have a new cam
and the head is milled, so you need to do some work - might as well shorten
the pushrods (you need tubular pushrods for this) to get the geometry
right. And, you have some loss in HP with all that weight up there - let's
get some roller rockers. Ah! Things are freeing up. A bit more HP, but
it'll wind up a lot easier.
Need more? Get the head flowed. Re-shape the combustion chambers a bit,
change to bronze valve guides... maybe stainless valves, just for laughs.
At this point, you'll have spent 3 or 4 thousand $$$ total, but a real good
head job might cost you another $1000 or more. A lot more if you go to a
well known shop. If you're not doing a lot of the work yourself, figure
another $1000 or so. Labor is expensive.
Need more? You better not. If you do, you'll be inching into real race
motor territory. And you're car will not be streetable.
That having been said, there are a lot of TR6's out there with motors in
the 150 - 165 HP range (flywheel HP) that are pretty reliable. Once you get
up into the 175 and higher range, you're going to give up a lot of
reliability and also the streetability of the motor. Plus, once you get
above 150 or so, you should think about super tough rods. And if want real
reliable, how about a billet crank?? Figure another $3 - $4k for Carillo
rods and the crank. Oh, might as well get forged pistons at this stage...
One option if to get a motor completely built by someone else that you can
just drop in. I know that Richard Good will do this, and I'm sure there are
others. Hey, you live in CA, give Huffaker a call.
The sky's the limit! You could spend $10 - 15K on a motor without really
trying too hard. Really.
BTW - you can get a lot of the HP gain without the Webers.
But they look great. (Hi Don S.)
C ya,
rml
TR6's
p.s. gotta go work on the rods some more... I'm looking to get 160 HP from
my car. It'll not be streetable. If the 160 HP works out and I get the car
dialed in and reliable - then I'm going to go for the 180+ range. Yes, I'm
sick. ;-)
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