Your results again are very impressive. Regardless of the combination of parts, a 355 making 490 ft/lbs at the flywheel will require volumetric efficiency approaching 120 percent. And you accomplished that with production heads and a small street cam. Professionals building state of the art race engines strive to achieve results like these. Great work indeed!Originally Posted by Fast355
That one was not mine, check out Something New Something Old by GM High Tech. I had a very similarly built 383 TPI in my 1983 G20 that put down 430 RWTQ.
Yes, that's making unbelievable power for sure. It took Super Chevy 28 build combinations in their danger mouse series to come up with very similar power as this LS engine and it required 40 thou more lift and 20 degrees more duration in their cam choice compared to yours. But, they also did it with the E-tec 170 heads which definitely are a really good head choice. Their torque started dropping like a rock below 3k rpm and was below 350 ft-lbs at the crank by 2600 rpm. If their torque continued to drop like the graph was showing then their engine certainly wouldn't be any better in the low end compared to the LS engine in this thread.
So, it's really impressive you came up with a combo that makes what, another 60-80 ft-lbs at 2400rpmthan SC managed and also beats their build all the way to 5k all while using a more tow friendly smaller cam.
In other words, your engine outgunning this LS engine all the way to 5k is still rather unbelievable.Your smaller cam should help the torque below 3k rpm but no way are you beating this LS engines torque all the way to 5k rpm.
http://www.superchevy.com/how-to/pro...block-part-28/
As for the TPI engine - full block work align honed, decked etc lighter pistons with 6" rods, ported heads, ported intake, ported runners, larger throttle body. Someone who knew what they were doing worked over the heads to get the flow numbers they got. You casually write the numbers as if it was a off the shelf Vortec and TPI build, but it was really an all-out build with very few expenses spared.
Last edited by lionelhutz; 07-02-2015 at 07:49 AM.
I love how this turned into a total apples and oranges debate. These engines being compared aren't even in the same ball park with budget or parts. Again, this is not a built engine. This is a JUNK YARD engine.
You are telling me you could take a PRODUCTION TPI 350 with 125k plus miles on it, put a cam in it, and destroy this engine? No way. Look at the length of the parts list and COST to make it beat this. Not to mention the 0411 ECM and other LS parts used... LOL
Considering this is Gearhead.... We all have a pretty good idea on the cost associated with making power like that in a SBC. Its WELL over 3k. Without dyno time I'm in this 2.4k. Then look at what it did without the new cam.... Subtract estimated value of cam kit. That puts a 419hp 444lb-ft engine at well under 2k.
Last edited by Skinny Pedal; 07-02-2015 at 09:43 AM.
Its still going to cost you a grand to swap that into a car and get it running. Not to mention to put down that kind of power and hold it you are going to need most of my parts list anyway. Cooling system, headers, cats, exhaust piping, muffler. My exhaust 2.75" mandrel bends are literally pieces of cut up GM truck tailpipes.
350 TPI Vortec with a cam and Acell runners will run this 6.0L all day long from idle to ~5k.
http://www.superchevy.com/how-to/061...k/viewall.html
0411 PCM was $50 at the junkyard and cost me $100 to license and $100 to convert to real time tuning capable operating system. LS engine is going to require tuning as well.
Last edited by Fast355; 07-02-2015 at 03:36 PM.
Apples and oranges, I'm sorry I tried to vary the tech here. It won't happen again.
Maybe next time bring a no expense spared LS engine to the party? I bet there was $2-3K spent on machining and porting that TPI engine's top-end alone. But it beats a junkyard pulled LQ4 with a cam and intake swap....
I appreciated the information on the new cam and the dyno results. LS swaps are super common these days but 20 years ago the SBC used to get the same abuse. There were always people around then arguing that their favorite engine , something other than a Chevy, made just as much power. Maybe... some guys do seem to do amazing things with an engine. But time marches on and the SBC is likely to continue to decrease in popularity while more and more LS family engines are available cheap in the wrecking yards. Cheap + available is what drives the "engine swap" market. So with that in mind, if you've found a way to make cheap + available more attractive, then I love to hear about it.Apples and oranges, I'm sorry I tried to vary the tech here. It won't happen again.
I thought this was some good tech info, I could read these kind of threads all day(minus the bs of course).
Last edited by hammered94; 07-02-2015 at 10:42 PM.
I guess these old 350s are just garbage and don't work in their intended environment or work efficiently LMAO!!
My brother and I drove from Fort Worth to San Antonio, TX today to pickup a Jeep Cherokee and a stranded cousin. He blew a radiator hose and the headgasket or cracked the head. I had to stop for fuel in Austin which is about 80 miles north of where I was headed. Cruised those 80 miles at about the 80-85 mph speed limit. Went and picked up a U-haul and the Jeep near downtown San Antonio. Then we all drove back home. ~ 270miles loaded with the A/C blasting and running 65-70 mph in 3rd gear turning 2,600-3,000 rpm. Drove 372 miles on 25.8 gallons, 270 of those miles pulling 6,500+ lbs and a trailer whose surge brakes did not seem to like to fully release for a couple of miles after bumping them. Picture was take right befor I let alot of air out of the Jeeps tires and strapped the suspension down with 15K ratcheting tie down straps. The 350 actually pulls the flats in 4th gear but pulling that kind of weight with a 3.73 gear it is a bit lugged for the cam in it. If I had 4.10s and or a 383 or both I would tow all over in overdrive. I did not nail it from a dead stop with the load, but I did kick it down to first gear a few times accelerating from the frontage road onto the on-ramp to better meet the 80 mph traffic. Pulls like a damn freight train from 2,500-5,200 rpm Tow/Haul shift points.
Last edited by Fast355; 07-04-2015 at 08:25 AM.
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