When is it fast enough?

Not sure if I'll need the flamesuit for this one but here goes.

Like most of us, I want to go fast. Fast daily car ranks pretty high up there on the list of neat things to have. Since I sold my LT1 Caprice and got into a TBI Roady, I've been planning on how best to go faster.

Simple enough plan, Vortec L31 block and heads, uprated cam (LT4 Hotcam most likely) and move over the TBI intake. Easy 350-ish(crank) ponies and still all GM bits and pieces to add to reliable cruiser. Cost overall of somewhere sub 2K and reusing old accessories it should drop right in. Whats the problem? It'll be quicker, but won't be fast. Sub 9 second 0-60 sure, but not fast in the current way of the world.

As I've been doing all this planning, I've been tuning and keeping the little TBI humming along. And it's been running great. Starts everyday, gets decent mileage (14-15 city, 20-21 Hwy) and does 0-60 in around 10.5 slow by most standards, but it's smooth and torquey. It's been flawless. Doesn't smoke, doesn't burn oil, doesn't overheat, only leaks when I run full synthetic, and with the open exhaust pipe it sounds like a proper v8.

It's too nice to tear out to put something more powerful in. When it eventually fails, which may be a while,( I used to have a 93 pickup with the TBI and we sold it at 350K+ miles. Original engine, but it's third transmission.) I'll put the l31 in.

I had no such problems back in highschool with my 71 Plymouth's 318 small block. It was a dog. 150 net ponies when new, lord knows what it was when I got it 25 years on. Leaked everywhere and overheated in traffic, then vaporlocked constantly. That engine I didn't miss when I ripped it out.

Anybody else finding the TBI too sweet an engine to tear out, or is it just me? The car runs great so it's hard to convince myself to do the modification.

Just you in this case, my friend.

But if it makes you happy, who cares? Enjoy it for what it is - a cruiser that can turn heads these days because it's unique.

Hi Raul

Your car runs good, looks good, engine runs decent, and get pretty good mileage. Why make the change? It's not broke, so don't fix it. When the time comes to redo the engine, then do it. Save the $$$.

My 2 cents

Hope to see you and your wife in Daytona this spring.

Tom

TBI engine is simple to work on and maintain. That's about it. lol.

I agree though, if it isn't giving you any trouble just leave it be. I prefer the cruising aspect of these big old beasts.

Though a quick/fast wagon is a nice thing as well

The trans went out on my 92 OCC, so, since I am swapping the trans, I thought I would put an upgraded engine in as well.

I am doing a conversion to Vortec heads. It has been a bit of a PITA. The only "bolt in" manifold is the GM unit at $477. I fudged a couple of adapters to a Weiand 4bbl manifold, but it is a PITA. The linkage needed an adapter plate, and modification to fit the Weiand manifold. The Weiand setup also raised the TBI about 1 inch, limiting the clearance for the toaster. A Spectrum short carb hat gave me clearance, but I had to get a 3/4 inch spacer to clear the top of the injector tower. A standard one might work just as well.

I am using an L99 cam and expect high 200s for HP. You can bolt the Vortec heads on the LO5 block, so rebuilding the block is good sense.

You need a slightly larger bore TBI for more HP. Stock is 42mm, so a 46mm should be sufficient. The larger ones from a 454 are supposed to be difficult to tune for. You may also need larger injectors, or an adjustable fuel pressure regulator. The metal fuel lines from a 91/92 FW has a Schrader port, and will bolt up. Your computer will require a custom chip. Use the LO5 water pump to keep the pulleys aligned. I put the electric fans from a 93 FW on in place of the mechanical one. I am using the relays from the FW, and setting them up to turn on the left at start, and the right with the AC on. I am also going to put a secondary circuit for the right at temps over 200 Deg. If you put a thicker radiator in the car, you may have to space the fans away from the core. I had to reshape the rubber parts to hold the thicker radiator. 94-96 fans may be a better choice, but the 93 FW relays are a stand alone setup.

Vortec heads will raise the exhaust manifolds/headers about an inch, can cause interference with the Y pipe, and duals can cause interference with the shift linkage.

There probably are some more petty things, so you can talk to if you need any more pointers.

Check your gear ratio. A 3.23 might give you some more umph.

The 3.23 is probably the reason why i'm in no hurry to change the motor. I'm still going to get the parts for the motor together (fun project) but it's nice to be in no hurry for it.

What engine is the l99 tho? Did you mean the l98?

Thanks for the heads up on the intake manifold issues!

The L99 is the 4.3 mini LT1.

BTW, you will have to bore out the distributor hole. The one on the OEM manifold is bigger than necessary, but you can use it as a guide. Make sure the distributor is not binding. You will also have to bore out the Chevy TBI intake for the larger TBI. There can be no "steps" for the flow to trip over.

Ah cool thanks! I kept looking up l99 and getting the 6.2 LS version.

an LS anything swap would be more economical,. even a 4.8 with some headers and tune is going to pull better and drink less fuel, look for a donor, van pkup etc, it's a well worn trail doing an LS swap.
JM2C

One of my favorite wagons to this day still was my '91 OCC with the 305. It was just a nice, fun cruiser.

Sometimes simpler is better...for now at least.

brokecello wrote:

One of my favorite wagons to this day still was my '91 OCC with the 305.  It was just a nice, fun cruiser.  

Sometimes simpler is better...for now at least.

Ditto, same car too (I bought it from Brokecello). At first I balked at 305 wagons but out of 13, 5 of them have been 305 cars. They get out of their own way well enough,, have plenty of torque at hwy speeds and are very easy and cheap to maintain. Plus they are cheaper as everyone wants a 350.....

brokecello wrote:

Sometimes simpler is better...for now at least.

now thats funny right there!!