L31 Extreme Budget Build

[Erik the Awful]

My stock steel tank in my 93 Camaro was useless at 5/8 of a tank on a road course.

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Holley Hydramat. It works. When we run out of gas on track, we're completely out of gas. There's no limping it back to the pits.

 

[Supercharged111]

Holley Performance Carbs & More at Summit Racing

The Holley brand is synonymous with automotive performance. Bring legendary Holley carburetors, EFI parts, and fuel system components to your ride.

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Holley Hydramat. It works. When we run out of gas on track, we're completely out of gas. There's no limping it back to the pits.

Last I looked I didn't see one that would push onto a stock pump.

 

[Erik the Awful]

Would any of these work?

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[tayto]

Part I am not looking forward to comes soon. The old fuel tank is coming out. I hated that stock TBI tank when this van was LS powered. Had to keep 1/3 tank or more in it or it would fall on its face launching hard or cornering hard. The new Spectre tank has a really nice baffle to it. Might have already posted the picture, but the Chinese got this part correct in the tank. The baffled area probably holds 3 gallons and it is probably 7" tall. It is going to keep some fuel at the pump pickup.

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i thought the spectre tanks were still made in canada? The dual tanks I got for my squarebody earlier this year were.

 

[Supercharged111]

Would any of these work?

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www.summitracing.com

Probably, I never knew they made adapters like that. The one push on that I did see was a monster.

 

[L31MaxExpress]

i thought the spectre tanks were still made in canada? The dual tanks I got for my squarebody earlier this year were.

Mine had Made in China on the box. We were in the middle of a line change on fuel tanks at Oreilly when I bought it, so it may very well have been a relabeled older part too.

Here is Spectra's condenser SNAFU! Must have been the design teams first day on the job and I am not sure how it got by actual test fitting in a vehicle. No way to mount the thing on the driver side the way it was shipped to me. I did send an email and picture to their Techline guys asking how this was supposed to fit. The stock image on their website shows the same thing and it appears they are no longer coating them as advertised to add insult to injury. Spectra has definitely fallen off. The condenser (6mm Pico tube)I bought 10 years ago for my 83 van fit perfectly and this condenser is the same unit, just redesigned. I like that this condenser is a microtube parallel flow, but not impressed that I will be making my own mounting and bending the hardlines on the condenser to the correct angles to mate with the vans OE hard lines.

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[tayto]

Mine had Made in China on the box. We were in the middle of a line change on fuel tanks at Oreilly when I bought it, so it may very well have been a relabeled older part too.

Here is Spectra's condenser SNAFU! Must have been the design teams first day on the job and I am not sure how it got by actual test fitting in a vehicle. No way to mount the thing on the driver side the way it was shipped to me. I did send an email and picture to their Techline guys asking how this was supposed to fit. The stock image on their website shows the same thing and it appears they are no longer coating them as advertised to add insult to injury. Spectra has definitely fallen off. The condenser (6mm Pico tube)I bought 10 years ago for my 83 van fit perfectly and this condenser is the same unit, just redesigned. I like that this condenser is a microtube parallel flow, but not impressed that I will be making my own mounting and bending the hardlines on the condenser to the correct angles to mate with the vans OE hard lines.

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Ya it's to bad,their rads and fuel tanks i've used in the past were usually good and actually fit.

 

[L31MaxExpress]

i thought the spectre tanks were still made in canada? The dual tanks I got for my squarebody earlier this year were.

I will say the tank I bought was extremely good quality though and it has a coating on it. It is going into place sometime this next week.

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[L31MaxExpress]

Pat just ran his budget L31 LT4 Hotcam build on the dyno. I had a very similar setup ~20 years ago. Low mileage junkyard L31 4-bolt main short block, LT4 Hotcam advanced 4°, GM 330 HP 350 HO Q-Jet manifold, Hamburger 1" tapered opening spacer, 850 cfm Q-Jet and Thorley tri-ys. Mine made 407 hp @ 5,600 and 438 tq @ 3,600 with 12° initial timing and 34° total timing at 3,100 rpm. Pat mentioned that he played with spacers and saw some good gains. My guess is another 10-15 hp with a 1" open center spacer. Probably has 10-20 ft/lbs of torque to gain as well if he messes with the advance curve in that HEI. His 1-3/4" headers are costing him some torque production as well compared to 1-5/8" units. With the Hotcam straight up, it is making power longer, but costing torque as well. With a reasonable stall speed and factory gearing he would have a better torque curve with that cam 4° advanced. The lift specs for the cam in the GM 604 engine he mention match the ZZ3/ZZ4 cam and that makes sense, since that is basically a factory GM sealed up (twist off bolts in places) ZZ6. When GM dropped the 113 heads that the ZZ3 and ZZ4 used, they put FastBurn heads on them and a single plane intake manifold and renamed them. The FastBurns could stand to have some work done to them the way they ship from GM and the single plane should go away atleast under a carb. A good dual plane adds about 30 ft/lbs to that engine. The single plane looks racey but that combination does not rev high enough to need it.

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[L31MaxExpress]

I set up the base map for this last night. I picked the engine size, cam size from the various ranges, as well as the 43.5 psi fuel pressure option to match the regulator. I let it build the base map, then I adjusted the timing settings. For now I set the Idle timing at 12° (which is the starting point of the " mechanical advance similar to initial advance of a regular distributor). I set the WOT timing to give 26° total at 3,600 rpm. I added to that 8° of vacuum advance. Edelbrocks vacuum advance function works like ported vacuum per the instruction sheet, kind of annoying but is what it is. I set the commanded idle for 650 rpm. The idle AFR is set for 14.1:1, the cruising afr to 15:1 (slightly leaner than the 14.1:1 stoich value of the common E10 fuel here) and the WOT is set for 12.5:1. I will see how that works, then creep up on more timing after it breaks in and I read the plugs. After this pig gets new tires, new U-joints and a new carrier bearing it may find its way on to a chassis dyno to optimize the fueling and timing as well as to find out what it makes. It should be able to make ~300 hp at the tires.

Here are some screenshots from the basic setup menu.

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