The Silver Buick's well Silver Buick!

[TheSilverBuick]

Agreed!

So my target HP number is essentially 500HP. I put 3.89 gears in with the hope of running ~118mph in the 1/4, which is 6,000rpm in 4th. For 3,800lbs, 500HP back calculates to 11.45ET, which assumes a good launch technique (which I most certainly do not have..), but without a roll bar I'm limited to 11.50 ET, so if I can bump against that ET and get good'ish fuel economy, I'll call it a win/win.

Going back and looking at it, I likely have 0.35 more compression.

[Scott Liggett]

What are your new cam's specs?

Looking at your package and your engine's size, I would think it would be making 50 ft lbs more torque and horsepower than what is in those dyno sheets even with a fairly mild cam.

[TheSilverBuick]

Going from a single pattern cam with 0.531" lift, 232º @ .050", 110 LSA, to a split pattern cam with In. 0.553" lift, 218º @ .050", Ex 0.571º lift, 223 @ .050" and big 116.8º (117º) LSA, which I installed at 110º ICL. Gas mileage cam

[squirrel]

That's a blower cam. Put an 8-71 on it.

[SuperBuickGuy]

or turbos
in that vein, there should be porn pictures of the bottom end of my 455, now 430, this week

[TheSilverBuick]

That's a blower cam. Put an 8-71 on it.

Might be a tad unhappy with 10.6:1 compression eh? I'm pondering some "cold air" ducting though since the engine bay air runs about 30ºF above ambient at speed.

[Scott Liggett]

Going from a single pattern cam with 0.531" lift, 232º @ .050", 110 LSA, to a split pattern cam with In. 0.553" lift, 218º @ .050", Ex 0.571º lift, 223 @ .050" and big 116.8º (117º) LSA, which I installed at 110º ICL. Gas mileage cam

All lift and short duration with wide LSA, all low end torque. You are going to need much bigger back tires. Don't expect this one to rev past 5000 rpm.

[hauen]

...all low end torque... Don't expect this one to rev past 5000 rpm.

Sounds like you need a truck, better yet, a Scout or maybe a Wagoneer!

[TheSilverBuick]

All lift and short duration with wide LSA, all low end torque. You are going to need much bigger back tires. Don't expect this one to rev past 5000 rpm.

You saw the dyno sheet, pulling to 6,000rpm if needed! Come on 25mpg!

[CDMBill]

The mileage will all come from very different places on the fuel and spark tables. Your comparison engine appears to suffer form fuel distribution issues and just planin old being fat. It'll be interesting to see where your combination settles in in terms of mean best timing at WOT and what the chamber tells you regarding WOT AFR. THat will end up being your target number across the power band. Then you can add advance and lean it out up to stoich for low load cruize parts of the table and get your 25 MPG.

[TheSilverBuick]

That test was on a dual plane intake and mine is a single plane that has equal runner distances. The dyno tests were at 34º timing, and I'll probably start at 32º since my static and dynamic compression is a tad higher. It was definitely fat, but the EZ-EFI system was "auto-tuning" so it appears to start on the rich and safe side. The second run leaned out a tad, but was still on the rich side. A few more pulls probably would of leaned out a bit more, but to what point? I'm not sure to what point it's adapting too. Typically these engines make best power around 13.0-13.3 AFR's, so 13.0 is probably what I'll shoot for at 32º timing until I see a reason to change it (like dyno time or such).

[TheSilverBuick]

This morning I re-torqued the heads after they've sat about a week so hopefully shouldn't see any head gasket issues. Also trimmed the oil dipstick and welded a slightly larger tube to the top of the oil dipstick tube so I could put a rubber stopper in it to make it air tight. Conveniently the stock dipstick still fits over the new tube.

[TheSilverBuick]

Since I'm going to a full time crankcase evacuation system, I wanted to add a little more for oil control at the port to minimize the amount of oil reaching the port. So I bolted a baffle over the port that should work pretty well in conjunction with the valley pan.



The valley pan will tuck up against the side of the new baffle when installed. The tin got a bit distorted during cleaning. I've already set it in the engine with the intake and all appears good.

[CDMBill]

What do you use for oil separation above the manifold?

[TheSilverBuick]

I'm going to build a catch can similar to the Firebird's. Basically a length of pipe with one baffle in it above the inlet (that connects to the engine), then above the baffle a piece of copper scouring pad/mesh, then an outlet connected to a vacuum source. The Firebird's vacuum source is currently a split between intake manifold and exhaust evac using a check valve on the intake manifold side. It has a petcock drain at the bottom that I drain out every other tank of gas or so. Usually collects a fair bit of water and a bit of oil, depending on the type of driving I've been doing. Periodically looking at the intake manifold connection, it doesn't appear to be sucking any oil, at least not in any noticeable amounts, so I think the catch can is working fairly well. The Skylark's evac point is better baffled than the Firebirds.

Here is a top view of the Firebird's. Its about 10" tall over all with about 4" or so of reservoir below the inlet point.