It decreaases gas flow. Roughly like putting to big a pipe on.
dt gebhard wrote:
> snip> As an immediate suggestion, dump the dual exhaust,
> > that's costing you
> > power.
> Please explain why this is true...
> Dave Gebhard
> 1977 Spit building power on a budget!!!!!!
> ----- Original Message -----
> From: "Terry Thompson" <epharisto@yahoo.com>
> To: <spitfires@autox.team.net>
> Sent: Thursday, November 30, 2000 9:43 AM
> Subject: Re: Engine Rebuild
>
> >
> > I don't know about 10,000 hp out of a single over head
> > cam four cylinder with about 100 cubic inches of
> > displacement, but I'd have to agree with every other
> > comment Nolan made.
> >
> > There's so many options and combinations of parts now
> > for spitfire blocks, it's difficult to say what is the
> > best set-up. I've been beating my head against a wall
> > trying to decide.
> >
> > Most people choose to work with what they have and
> > what is proven by using the Triumph Competition Prep
> > Manuals. You'd use existing blocks, heads and cranks
> > that are machined for balance, weight reduction and
> > flow. And upgrade to over-sized pistons (TR6), sport
> > cam, and higher flow carbs.
> >
> > But if you want to spend some deneiro, there are
> > forged and aluminum pistons ($500), chrome-moly
> > connecting rods ($700), billet cranks ($3k), titanium
> > valves ($400), quad carb setups ($1k) or electronic
> > ignition systems ($2k), superchargers ($2k) and
> > six-hundred dollar roller-rockers that will work on a
> > spitfire engine. And you can spend some good money on
> > ceramic coatings (especially if you start coating
> > everything including timing chains and roller rockers
> > etc.)
> >
> > First: try and set a limit to what you are willing to
> > spend. Then look at all of the options that are out
> > there, and decide which ones will fit within your
> > budget. (make sure you figure in some buffer for
> > incidentals like hardware gaskets etc.)
> >
> > Then take the list of items that you think will work,
> > and ask someone like Mike Lewis of Protius or Ted
> > Schumacher of TSI if it's a good plan to put those
> > pieces together. Some things are sort of common
> > sense...like buying a $2000 super charger and using it
> > on a ZS carb and stock cam...probably not the best use
> > of your $2000.
> >
> > You can easily surpass $10,000.00 on parts and
> > services alone if you add it all up.
> >
> > In the least you should have the block and head
> > hot-tanked and magnafluxed. And consider shotpeening
> > on cylinder walls. Machining the engine as described
> > in the competition prep manual is not the cheapest
> > thing but does improve upon an already proven engine
> > design.
> >
> > Companies like PAECO will sell you a stage 1,2,3,4
> > engine but the stage 1's (pretty stock except for a
> > hotter road cam and head porting as well as balancing)
> > start around $3,000. The stage 2s are around $5,000
> > and the 3's and 4's they don't list because it depends
> > on what performance components you choose. The above
> > prices also required your old engine as a trade in.
> >
> > Now for other problems. Let's say you've gone ahead
> > and spent $10,000 on your engine and it's built
> > producing close to 200 horses. I'd like to start a $1
> > pool and see who can guess how long it will take
> > before you tear the differential or transmission out
> > of your car when you excellerate too fast.
> >
> > The triumph components are well made, but even the
> > works spitfires with their estimated 100 hp, had
> > modified TR4 tranny components for more beefiness. In
> > the least, such an engine will probably go through
> > U-joints at an alarming rate and torsion on other
> > components like your drive-shaft and half axles will
> > take it's toll. Not to mention that such an engine
> > requires lots of care and upkeep beyond that of a
> > stock TR. Constant adjustments to roller rockers and
> > valves are gaurenteed.
> >
> > I'm not trying to discourage you. Just that there's a
> > whole lot to think about, and no one out there has yet
> > been able to say "this is the best combination". I'm
> > still (after 4 months) mulling over my twenty thousand
> > dollar list of options to decide which items I'm
> > willing to take a chance on and which I'm going to
> > red-line to bring the whole concept into budget.
> >
> > I'm actually shooting for a HP range but it's
> > difficult to tell what sort of affect/effect (?) these
> > parts will have to boost hp. If it's marginal (Eh,
> > you'll get another 5 horses out of that $3,000.00
> > part) then off list it goes. Especially since everyone
> > you talk to has a different opinion about what is good
> > hp value for the dollar.
> >
> > But then the greatest fear is spending several
> > thousands of dollars on engine components, then
> > getting it bench dyno-tested and instead of your 57
> > bhp, you get a 59 hp. Or what is probably even worse
> > and more likely, you over-shoot your optimal HP goal
> > and your having to crawl everywhere so you don't tear
> > out your drive-train. Then there's always the
> > possibility that someone didn't torque something right
> > and you throw a $250 forged piston head through your
> > $2000 ported, polished, titanium valved, ceramic
> > coated head (and your recently painted bonnet to
> > boot).
> >
> > -Terry
> > "Oh...Those are speed holes. They make the car go
> > faster" - Homer Simpson
> >
> > --- Nolan Penney <npenney@erols.com> wrote:
> > >
> > > There's an old saying "speed costs money, how fast
> > > can you afford to
> > > go?" It's as valid today, with you, as it was then.
> > > If you've got the
> > > money, you can get 10,000 horsepower out of that
> > > engine. Gonna cost you
> > > upwards of half to a full million dollars, but it
> > > can be done. I say
> > > that to point out the folly of your question. You
> > > need to put some
> > > parameters in it. What kind of money do you want to
> > > spend? What kind
> > > of performance do you want? What about life
> > > expectency? These things
> > > all sway the modifications. After all, nitros and
> > > 40psi of boost are
> > > great power increasers, but life expectency is
> > > rather short.
> > >
> > > As far as every trick in the book, pick up every
> > > engine book ever
> > > written, and study them. Then, you will no most of
> > > the tricks in the
> > > book for squeezing power out of your engine. And as
> > > soon as you've done
> > > that, know you're out of date immediately, because
> > > in the time it took
> > > you to read these words, at least 60 new tricks have
> > > been discovered or
> > > improved on.
> > >
> > > As an immediate suggestion, dump the dual exhaust,
> > > that's costing you
> > > power. Then do some serious tuning (how did you
> > > select the needles?
> > > what is your advance curve? etc)
> >
> >
> > __________________________________________________
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