jb78L-82

Adam,

I reused the OEM Aluminum L-82 intake. I did so for a number of reasons:

1. I wanted to be sure that I could keep the L-82 GM CAI dual snorkel dual intake and using an aftermarket intake would have prevented me from doing that. I wanted to keep as much L-82 as possible while at the same time dramatically increasing the HP/TQ.

2. Since the engine would live in the 2,500-5,000 RPM rev range 95% of the time, I felt that an aftermarket intake would not add much to the equation in terms of power and torque.

3. After speaking with the builder who did the bottom end of the L-82 and who worked for GM for 16 years as a field tech (owns his own high performance shop now), he told me that leaving the L-82 intake on my engine built as it was would not hurt performance much at all (5-10 HP, at most). If the engine was going to spend some time above 6,000 RPM, which it was not, an aftermarket intake would help more make max power. The Howards Roller cam makes its power from 1,500-5,600 RPM....

4. I did take my L-82 intake to the builder for a minor cleanup before the reinstall.

5. Early in my car hobby experience with my Nova SS during college when I swapped out the cast iron GM intake for an aluminum edelbrock performer (the only change at that time) was disappointing in terms power increase....slightly better power...Not a great example since the 350 had the OEM cam and OEM cast iron heads but nonetheless....

6. Replacing the restrictive Shorty Headers (McJacks with 2 inch outlet) with Long Tube Headers (1 3/4 inch primaries/3 inch collector, hopefully soon!) would be MUCH more beneficial to the motor versus an intake change

gkull

Race cars like winged Sprint cars go around dirt tracks ovals and they don't have any belts or alternator. dragsters either

99 Black Bird TA

230/236 comp cams XE lobes 110 :') 2 degrees of advance ground in, custom distributor curve from Sun machine, twin spal electric fans come on at 180, temp stays under 210 at all times, thermostat is 160, custom Griffin selected by the engine builder, My car is typically 190ish when it's hot, checked with calibrated gauge. TH400 & 3200 stall is some of the extra heat.

The Money Pit

How is the low end power of this during normal stop/go? My long term goal I think is to go solid roller about 250@.050 and on a 106 LC, and swap my gears to 4.10. Then tweak the converter for the best feel. I figure low 11 seconds maybe tickle high 10's....but mostly street,....not so much strip.

v2racing

It actually pulls very strong on the bottom. In the 80 it was pulling 3.08 gears and it yanked hard. Traction was a problem. The 4.11 gears are going to make it impossible to hook up.

I used lobes that are fairly aggressive, narrow at .006". Combined with the high compression, it makes for a strong, wide power-band.

Mike

The Money Pit

Thanks for that feedback. I went to MT 295 55 15 drag radials for the same reason. Couldn't even put full power down after the second gear shift with street tires. Not a problem now.

Looks like Monday I'll be calling AFR to place the order.

Thanks to everyone on here. Been a great help.

augiedoggy

If I remember right my 355 has a .034-36 quench.... I had .019 deck height with the flat top 4 relief pistons and I used the .015 steel shim gaskets but I did spray them with the permatex spray copper gasket spray when mounting the iron eagle 64cc heads... I think I had 9.7:1 compression and it does run great on 91. I have run 89 and not noticed pinging but normally use the 91 for piece of mind. I have the high-rise vented greenwood hood and the 14" air cleaner with the filter top so I believe it get fairly cool air while moving. The lunati 262-268 cam brings my dynamic compression down though.

SDVette

Visiting from the C1 section.. Interesting discussion. I have a 1970 LT-1 (11:1, solid lifter) motor in my '61. I have to pull a few degrees of timing to run on 91 (So. Cal) without pinging.

The Money Pit

So I called and ordered the heads this morning....a 4 to 6 week lead time , which I sort of expected. While discussing the order, decided on 75 cc chambers for two very good reasons. First was gas quality, and running on the ragged edge as I would have been, may have me faced with a tank of gas that pinged for 300 miles. The better reason, was in the future a 427 short block would allow me to repurpose the heads for that rendition...and still have a reasonable pump gas compression.

Thanks again for all the input.

RBrid

Hey Adam, I just want to make sure you know the Shell stations in our area sell 92 octane gas. -R

gkull

You can order pistons in any dish size. As you look at high performance heads for big ci small blocks they might be as low as 38 cc. Flame travel and exposing less cc of the head chamber to heat to being lost to the cooling system.

My 64 cc heads have been resurfaced and are more like 62 cc on my 427 and now bored out to 434. I always thought it would have been nice to just get some 58 cc

The Money Pit

George,

When I get ready to build my 427.....(no time soon), I might take a trip out to see you. Maybe a test drive in your vette?

With no real sources of experts near me, I do rely a lot on guys like you for advice.

boat196

Without knowing your specific piston volume, I would say your in the range of 10.30 - 10.52 static compression. The IVC affects dynamic compression

domenic tallarita

I ran water injection on a street car and when I couldn't get av-gas the water stopped the ping. Edelbrock made the water injection and it injected according to vacuum and RPM.

Dom

Kacyc3

current configuration is 406 11:1 alum heads with efi, 36* no pinging, old config was same engine w/flat top pistons, 58 cc heads small cam and 750dp holley, couldnt run more than 32* or it pinged.

domenic tallarita

Like to add one more thing! when using the water injection I was able to keep the same timing that I used with Av-gas. When I was only using the water system I was able to tell when the water ran out (about a tank) because it would start pinging. Also the water kept the carbon buildup on the top of the pistons down.

Dom

cv67

http://www.snowperformance.net/?gcli...FQqFfgodqdQB-g

Had one on a 90 ZR1 it definitely helped
No methanol (big mistake found out!) 50/50 winshield washer fluid and water only had it come on at 3/4 throttle and above
Pinging disappeared do recommend sounds goofy but it works.