Can I convert Chevy 350 4bbl block to TPI
Peter Crowl
like to go to TPI. If I buy a donor car with TPI, can I swap over the intake
and controls to the block I have?
I see a possible problem with block sensors...but thought I'd ask here.
The motor I have is a GM Factory Rebuilt or possibly Crate motor. Probably
mid 80's vintage. Has very low miles - of course I'd open up the bottom end
to check condition before going through the brain damage.
Thanks!
Peter
JazzMan
Not all that hard to do, though issues on intake manifold
compatibility are a concern. It might be easier to use an
adapter plate to adapt the throttle body to the intake.
Other items like EGR, sensors, etc. can be worked out if
you're fairly mechanically/electrically inclined. Try this
site: http://www.diy-efi.org
JazzMan
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PA-ter
cut at different angles where they mate to the intake. Aftermarket
(Holley, Edelbrock) people make kits that come with everything,
including an ECM, to make the swap easily but are expensive. Using
factory stuff will work but figuring out the wiring, sensors &
finding a compatable computor will be a time consuming & probably
aggravating deal. If you have the patience & the knowhow, have at it.
If you have the $$$, go aftermarket. Also the afterfactory computors
are fully adjustable, making end fuel mixture a snap. Good luck.
Mad Dog
w/o reverse flow cooling.
I know the early 5.0 litre motors with TPI are
compatible but the chamber size is quite smaller
and would bump the compression up beyond
streetability.
Maybe you meant to say you wanted TBI
(throttle body injection) which is different than
TPI (tuned port injection)
Ther are plenty of 5.7 litre TBI motors rusting
away you could swap out with.
--
Mad Dog
--
"Peter Crowl" <pcr...@earthlink.net> wrote in message
news:bJ1Hc.8526$R36....@newsread2.news.pas.earthlink.net...
Peter Crowl
:~)
TBI could adapt? Hmmm...that would be better than nothing. Keeping a carb
motor running on the "Motor Fuel" we are sold is getting harder and
harder...add to that a motorhome's tendency to vaporlock due to engine room
heat and you've got problems.
So if I were to go TBI I'd either adapt the TBI to my intake manifold or
swap heads and all? Any compression issues swapping to TBI heads?
Peter
"Mad Dog" <m...@privacy.net> wrote in message
news:2l4rolF...@uni-berlin.de...
Mad Dog
5.7 litres on the T.P.I. version they also adopted a reverse flow cooling
system
which is not compatible with early model engine blocks.
-I've been wrong before-
The early TPI 5.0 motor has small chamber heads and very restrictive
intake ports.
As a rule of thumb for every point increase in compression the octane value
of fuel must be increased, with a compression ratio of 8.5:1 you would
simply
slide the decimal point 1 place to the right and find that this compression
ratio
requires 85 octane fuel.
9.5:1 compression is happy with 95 octane fuel etc etc
Spark timing, fuel mixture and shape of the combustion chamber have
the ability to allow a particular engine combination to survive on the
street using lower octane ratings.
aluminum heads dissipate heat faster than iron helping also.
To make a long story short i would attempt to cure the vapor lock
by insulating the fuel lines, using a non-conductive carb. spacer,
adopting a ram-air system for the air cleaner assy. and possibly
acquiring a "air-gap" manifold like the one that Edelbrock makes.
These manifolds separate the intake runners from the valley cover and
allow the carb. to run cooler.
here is a link to the Edelbrock manifold page
http://www.edelbrock.com/automotive/index.html
check out the performer air-gap model, it is compatible
with square or spreadbore carbs.
Good luck friend.............news:hhbHc.8899$R36...@newsread2.news.pas.earthlink.net...
Rex B
||Correct me if i'm wrong but i think when chevrolet increased displacement to
|| 5.7 litres on the T.P.I. version they also adopted a reverse flow cooling
||system
I think the LT1 was regular flow, but the LS1 was reverse flow.
But TPI preceded these engines. The IROC Camaros used TPI, first on a 305, later
on a 350.
I'm sure it can be done. There are several good tech books on Chevrolet FI
engines and modifications.
As for TBI, one option is the Holley retro-fit kits. I doubt anything else
will work with the manifold you have now. If you are OK with changing
manifolds, I'd look at buy a pre-95 TPI engine. Get one from a truck if
possible, and of course get a wiring harness and ECM with it.
There is a wealth of info out there on doing this.
Texas Parts Guy
Bruce Chang
"Rex B" <NOSP...@REMOVEtxol.net> wrote in message
news:40ed5dcb....@news.txol.net...
TPI came out in the mid 80's, I believe 84 for the corvette. The LT1 came
out in the early 90's, I believe 92 for the corvette and it is reverse flow,
the TPI engine is a standard flow SBC.
If you get a TPI engine, as someone else said, you'll need to check the
heads, there are different angle heads on different TPI engines. (I think
pre-87's were different than 88+ engines).
If you get a donor car, that would be perfect because you'll have everything
you need to do the swap. An issue is if the wire harness isn't as long as
the one you've got now. You may need to lengthen the harness or you can get
one from Painless wire harness. I don't think there should be any sensor
problems as the block is the same as any other SBC block of that era. A
donor car will also come with all the necessary brackets and accessories
that you'll need though you might be able to use the ones you already have.
I don't know enough about your car to be able to say. I'd agree with Rex
and say that it can be done and it'd be a fun project. If you need some
help on the swap, you might go to www.thirdgen.org and look in their tech
articles to see what parts you need to make the swap.
Good luck,
-Bruce
Mad Dog
with the newer heads (vortec)
i believe.
--
Mad Dog
--
"Bruce Chang" <bec...@swspambegonebell.net> wrote in message
news:bTdHc.7148$A64....@newssvr23.news.prodigy.com...
Bruce Chang
> that's right, the '88 up use a different bolt pattern on the intake
manifold
> with the newer heads (vortec)
> i believe.
> --
> Mad Dog
AFAIK, the vortec heads are yet another different bolt pattern than the
'88-up and pre-88.
Scoggin Dickey sells a TPI manifold that will fit vortec heads.
Peter Crowl
was presuming I'd swap the heads as well....but if I understand what has
been said here correctly that's another bolt pattern to be careful of. The
reason I'm thinking about saving he 350 I have is that a donor at the right
price is liable to be high mileage. The block may be clapped out but the
intake should still be good. Put that intake on my good block and away we
go...or so it is hoped.
I've done an LT1 swap --- put one in an XJ-6. That's a well documented swap
but it was a good learning experience with regard to the harness and
sensors. I bought the entire package with the 4L60-E , harness, fans and
all.
In this case, I really want to be able to stay with an engine driven fan as
the engine is mounted in the rear and is pulling air through the radiator
against the natural vacuum at the rear of the vehicle. Hot air is then
pulled over the motor and flows down and out....but a lot gets recirculated
and so I need all the fan I can get. Hmm---does anybody make a reverse flow
fan which would push air through the fan? That and some scoops would cool
things much better....but I have doubts that an electric fan would do the
job...especially here in Denver.
This is what I'm working on.
http://www2.onu.edu/~kwildman/ultraVan.html
.mine is one of 60 they built with V8 power. Originally a 307 with a
Powerglide...mine has been swapped out for a 350/Turbo 400.
Thanks for all the help and links...I appreciate it all!
Peter
Bruce Chang
Does yours have the smiley on the front? =o)
I think you'd be surprised how much air electric fans can move. Go here and
take a gander. http://www.flex-a-lite.com/auto/html/monster-electric.html.
Reverse flow cooling is only the LT1 or later. You won't have to worry
about it if you have an earlier generation SBC.
You won't find a donor car with vortec heads and a TPI baseplate that fits
it unless you're amazingly lucky and someone was amazingly dumb. There are
plenty of TPI parts on ebay as well as at swap meets, it's just hard to find
one that is complete with most of the things you'll need for the swap. For
a 350, you'll need to get 22# injectors, associated PROM and possibly the
knock sensor but for the most part, everything else is the same for the
305's and 350's you'll find at the boneyard. You'll also need to decide if
you want to go speed density (SD) or Mass Air Flow (MAF). There are two
different computers and the harness has different connectors for them
(though it can be adapted from one to the other or vice versa). The MAF
system is a bit more forgiving for tuning but the MAF is a delicate sensor
and doesn't have great reliability. Some people prefer SD because you won't
need the MAF sensor and SD is newer and newer is always better. <g>
-Bruce
Mad Dog
ROFL, just kiddin
make some scoops and use marine blower fans
(1 on each side) to force fresh air into the compartment.news:jufHc.9190$R36....@newsread2.news.pas.earthlink.net...
Rex B
||the engine is mounted in the rear and is pulling air through the radiator
||against the natural vacuum at the rear of the vehicle. Hot air is then
||pulled over the motor and flows down and out....but a lot gets recirculated
||and so I need all the fan I can get. Hmm---does anybody make a reverse flow
||fan which would push air through the fan? That and some scoops would cool
||things much better....but I have doubts that an electric fan would do the
||job...especially here in Denver.
There are some very good, powerful and efficient electric fans on the market.
The best of these should outperform the best engine-driven fan.
Many engine-driven fan designs have blades that would appear to work with either
rotation. The question I'd have is whether a fan clutch is reversible in
direction. I suspect a viscous-drive-only unit would be reversible, but perhaps
not a thermal one. You would want thermal.
It might be worth calling Hayden about that.
Texas Parts Guy
Peter Crowl
all over it. I'll have to make a custom shroud and some internal air dams to
direct flow but I think it would be far better than what I have. Is there an
advantage to mounting two fans face to face pulling and pushing?
Sounds like my best course will be the obvious one...buy a decent donor and
use the whole package, block and all. If I get an SUV or PU the ECU should
match the Ultra Van weight and load characteristics pretty well...Sounds
like trying to save my 350 LB is false economy...I can probably sell it as a
complete engine and recoup at least something.
Did I mention that the engine/trans faces rearward and is then coupled to a
Walters Marine V drive which reverses the drive line back into a Corvette
rear end?
And you thought RV's were boring!!
Peter
Rex B
||Did I mention that the engine/trans faces rearward and is then coupled to a
||Walters Marine V drive which reverses the drive line back into a Corvette
||rear end?
Are you sure it's not actually a boat that's stuck to the trailer??
Sounds like a cool RV.
Texas Parts Guy
Peter Crowl
chassis...just a rear subframe for the motor. It's all about aluminum ribs
and stressed skin as you'd find in an aircraft. It is pretty cool and a
piece of history worth saving.
Peter
"Rex B" <NOSP...@REMOVEtxol.net> wrote in message
news:40eeafdd....@news.txol.net...
Ken Moon
You could give the folks at Edelbrock a call. They used to have a TBI system
that would bolt on to your 4-BBL manifold. It got good reviews in comparison
to carb at the time (15 years ago).