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Re: SBC engine is 60 years old.

Posted: Fri Mar 27, 2015 7:35 am
by Money pit Beretta
TBI is an inlet restriction, TPI can work.....but really is not the best for flow(older style plenums were too boxy), the newer style is much better. As said the best is MPFI. I spent a lot of time looking into this on my 67 Camaro.
Carbs always win when it comes to top end HP. EFI is better for power over all RPMs(less peak). I sure don't miss trying to tune a carb or messing with points. Did love the old HEI though!

Re: SBC engine is 60 years old.

Posted: Fri Mar 27, 2015 7:57 am
by woody90gtz
TBI is not necessarily an inlet restriction. The aftermarket TBI setups like Fast and Holley flow 750+ cfm. It's just the wet flow intake that leaves a little to be desired. Having the injector closer to the valve helps with the throttle response.

And even the stock TBI on my truck (which I smoothed to help a little) is sufficient for my purpose. Stock they flow about 490cfm, and calculators tell me I need 464cfm since I only spin it to 5000rpm. TPI would actually be great for my truck because they are torquey. Problem is it is expensive when you need a Vortec base for the TPI stuff. I'd love to find a used setup and see how much better it is than TBI.

Re: SBC engine is 60 years old.

Posted: Fri Mar 27, 2015 7:05 pm
by Money pit Beretta
I must have remembered that wrong. I think Car Craft or Hot Rod did a test on them. Guess it could have been a disruption of flow that didn't happen with a carb.
Doesn't Edelbrock have a lower intake for TPI made to fit the Vortec? Then you just use stock stuff after that.

Re: SBC engine is 60 years old.

Posted: Fri Mar 27, 2015 7:27 pm
by woody90gtz
Yeah, but the Vortec TPI base is like $500. Ouch.

The stock GM TBI has injectors that probably disrupt the air flow more than a venturi booster on a carb. They are pretty big. That's another plus about port fuel - there's nothing to get in the way,

Re: SBC engine is 60 years old.

Posted: Fri Mar 27, 2015 9:05 pm
by Money pit Beretta
Boy I'm out of touch, last I saw it was $325 and that was too much! Yeah port fueling seemed like this great new thing when I got my 90GT(well it was new to me in 96). My first FI was cross fire(or crap fire), what a stupid system. More fuel pooling at idle, how is that a good idea? Oh and the half size runners on the intake. Not even going to start on the wide open plenum.

Re: SBC engine is 60 years old.

Posted: Sun Apr 12, 2015 2:38 pm
by Rettax3
Awesome that you have had that engine for so long -12.5:1 is severe these days (no lead), that would be a beast even by today's standards. I love those M/T valve-covers too -I had a set of them from my old '70 Monte Carlo, they should still be in storage... I still want a set for the engine in my old Plymouth... Now THAT is a 383! :good:

Woody -you have probably already considered a 454 TBI unit upgrade (bolts on), but that gives a huge airflow advantage over the SBC TBI. I personally love the GM TBI -there are two injectors to replace if something wears out, and you can see them operate by pulling off the aircleaner. 10psi of fuel pressure is enough to run them too. My 'old' '88 Camaro thinks it is a 305 TBI, it is actually a 350k+ mile GMC Vandura 350 with a mild (and probably worn out) RV cam, roller lifters, and a heavily ported CFI mainfold modded to bolt onto the newer TBI heads... It will kick the toast out of my '89 RS (both are five-speed cars, rear-disc Posi with the same highway gears, but one is a ten-bolt and the RS has a nine-bolt BW 'Austrailian' axle) all day long, despite the RS having a Police Special 5.7. Yes, the TBI leaves some to be desired, but it is bullet-proof, almost zero maintenance, and has some growing room if you need.

Re: SBC engine is 60 years old.

Posted: Mon Apr 13, 2015 10:14 am
by ifixalot
I put on stud girdles and roller rockers so the M/Ts had to go.
I put on Moroso valve covers. The motor just sits on a stand in the
corner of the garage. I tried to sell it a couple times on craigslist
but the buyers never show up. I got tired of answering questions
and then they never show.
Here is a photo of how it sits today.

Re: SBC engine is 60 years old.

Posted: Mon Apr 13, 2015 7:56 pm
by Money pit Beretta
Wow a generator!

Re: SBC engine is 60 years old.

Posted: Tue Apr 14, 2015 9:48 am
by ifixalot
No, I think you are referring to the home made setup using heater blower motor to power the water pump.
That was the setup back then, to use the HP for moving the car instead of using it to move the water in the engine.
Plus you could circulate the water and cool the engine down while it was not running.

Re: SBC engine is 60 years old.

Posted: Tue Apr 14, 2015 9:57 am
by 3X00-Modified
HAHA that's creative... The time before an electric water pump existed..

Re: SBC engine is 60 years old.

Posted: Tue Apr 14, 2015 6:35 pm
by Money pit Beretta
That is a great mod for way back then!

Re: SBC engine is 60 years old.

Posted: Tue Apr 14, 2015 8:36 pm
by Asylum
I trust you turn it over now and then and prime the oil pump.

Valves shouldn't stay stuck open for extended periods and valve springs get weak when compressed for a long time.

I see the exhaust ports are exposed so that would be a concern over an extended period of time.

Just a thought.

Re: SBC engine is 60 years old.

Posted: Tue Apr 14, 2015 10:50 pm
by 3X00-Modified
I think it's more of a trophy than an expected to run engine.

Re: SBC engine is 60 years old.

Posted: Wed Apr 15, 2015 8:06 am
by woody90gtz
Looky here...a modern electric water pump! haha

I'm kinda going to miss my old 355...first SBC I ever built. But the new one should help me get over it. haha

Image

Re: SBC engine is 60 years old.

Posted: Wed Apr 15, 2015 9:13 am
by ifixalot
You youngins have it so easy today, pre-made elecrtric water pumps geez!
Why when I was in school I had to walk 5 miles each day, up hill both ways!!!