1978 Lincoln Continental Coupe

[Basement Paul]

Maybe for Xmas you guys can buy each other half of an electric impact gun and an aluminum jack.

Who's going to be first to open up the exhaust at the track?

-BP

[wxo]

After lifting and moving that jack around the back of my truck for this trip, I believe an aluminum jack is in our racing future. That thing is a gut buster!
As for the open exhaust, I do have a cutout on my exhaust, but I don't think it does much good since I have a straight flow-through muffler anyway.
Regardless, I tried to remove the cap of the cutout at the track, but the threads were too corroded to easily remove it. I had forgotten to chase the threads before the trip.

[Maverick]

I ordered #110 jets in late November and a metering block on 12/5 from QuickFuel and BOTH are STILL on backorder. They're saying 12/26 but who knows? I think Holley is not giving QuickFuel the love it needs.

[Maverick]

Wow, you really got that thing dialed in pretty well. That's really good ET for the MPH. Looks like a fun day!

-Dave

Been thinking about Smoke's comment on ET vs MPH. According to Geoffrey Fox's Formulas:

. It only takes 353 HP at the flywheel HP (FWHP) to get a 4600# car to 97.7 MPH (my best run) in the 1/4 mile

. But, it takes 450 FWHP to get a 4600# car thru the 1/4 mile in 13.61 seconds (same run) .

I expected diminished performance on the top end due to the aerodynamics of the brick. It surprised me that the aerodynamics of the Lincoln are apparently worse than that of the TB SS with its larger frontal area. Apparently so since the Lincoln and TB SS are about the same thru the 1/8th but the TB SS runs away in the second half of the 1/4. What else could it be but aerodynamics?

[GMJohnny]

This question reminds me of when I put a 600 Holley on my 403 Oldsmobile.
It was like lightening out of the hole, but the come on wasn't there. I might
be inclined to think a bigger cfm carb or an intake that flows better might
be some help. I'm not sure what other guys running your motor package run,
but it might be worth looking into.

GM

[wxo]

We never did get Maverick's QuickFuel 750 cfm carb rich enough at WOT. We ran out of big jets. I believe there's room for improvement there.

[Fred32v]

Go big or go home, maybe a Holley Avenger 870 or something.
Don't we know someone with a larger carb you could try? Just sayin'.

Oh, what the hell, looks like time for Fuel Injection,
you and a little help from WXO have mastered most everything else.

[wxo]

We still have the #110 jets and bigger secondary power valve on the way. I believe they will do the trick.
100 MPH club, here we come.

[TireSmoker]

Isn't that thing 520+ cubic inches? What RPM are you shifting it at? I'm guessing it would benefit, HP-wise, from an 850 cfm unit.

What else could it be but aerodynamics?

It'd be interesting to see how the aero would be figured out mathematically.

But the other possibility is gearing, maybe. What gear and RPM are you crossing the finish line at? I'm guessing you're in 3rd, but probably well under 5000 RPM. If you swapped your 3.25s (I think thats what it has?) for say 3.73 or 4.10s, you're going to be higher up in the RPM range in 3rd gear, where you are generating more HP and able to then make more MPH.

As for EFI, Holley just released their Sniper setup, which will bolt onto a conventional 4bbl intake..

-Dave

[Maverick]

Anyone know what the vacuum should be when wound out at WOT? Wouldn't near-zero vacuum indicate the carb was big enough to go with that intake, heads and exhaust?

On the other hand, carb sizing program says my application (521 CI and 5500 RPM) should have 900 CFM for RACE. ("Race" might assume bigger heads, single plane intake and open exhaust.) But, only 6XX CFM for street. My first priority is good street manners so 750 seems like a good middle ground.

When we went from #96 to #99 secondary jets, we saw no change to the lean AFR. Fuel pressure was good so we took that to mean the fuel flow was being restricted by something other than the jets. Thought maybe the needle valves were too small so we replaced the .110"s with .130"s. Still didn't get us to mid 12s AFR. That's when the #110 jets and secondary metering block with power valve were ordered. Here's hoping the secondary power valve will do the trick. As far as I know, the metering block and #110 jets STILL haven't shipped.

I'm not sure exactly where on the track the 2-3 shift occurs but, according to speed, it should be right around the 1/8th mile marker. So, the second 1/8th mile is run in 3rd gear, not totally wound out.

I could put an electric fan on it to eliminate the fan load at high RPMs. It has a centrifugal fan clutch that's supposed to slip at high RPMs but electric would eliminate whatever load is still there.

[Fred32v]

On my 461 Oldsmobile, at WOT the vacuum needle would be laying on the peg, not dancing.
I can't remember all the carbs that were on it, but I think the last one was a duel feed Holley
800 spread-bore with mechanical secondaries. (I think, maybe one of my boys can confirm.)

Grins!

[Maverick]

Good input. Thanks!

[MostMint]

That vacuum gauge should be at 0 at WOT - period. If there is a hint of movement the carb is too small. Now just because you see 0 does not mean the carb is good. I ran a 750 mechanical secondary on my cast iron head 350 Chevy.

Larger carb will improve flow by reducing restriction from the carb. Since the carb meters fuel based on the signal in the venturis, all you need to do is have a large enough accelerator pump shot to overcome the air stall when you mash it. The same logic applies when using mechanical secondaries - even though that has been dismissed here up to this point.

I would start with an 850 on something that big with that much power.

[Basement Paul]

I ran an 870 Street Avenger from Holley on my Caddy. It was not nearly as hairy as your Lincoln motor, weighed about the same, and I would always be running 99+ MPH. It's a nice blend of streetability and top end pull. I would make the switch. I believe that motor will come to life once the cam comes in and the secondaries open.

-BP

[Maverick]

So, the top end would be better with a bigger carb. And, a bigger carb wouldn't hurt driveability. Good to know even if it won't get a bigger one. If the El Camino gets some performance improvements, that will be good input.

I'm shifting at 5200-5500. Shift light is set for 5000 but RPMs approach 5500 by the time I get it done. Cast rotating assembly is rated for 5500. Can't say for sure what RPM it's at at the end of the 1/4. RPM calculator puts it at 4500 at 98 MPH with the short drag radials which sounds about right. 3.25 gears are as steep as I want for cruising. Its turning 3000 at 70 MPH with street tires. Steeper would be fun with an OD transmission but there's no affordable way to get one.

Here's wishing all TireSmokers a Merry Christmas and and Happy and Healthy 2017!! You guys make my wrenching more fun.