Build me a GM Gasser tow motor for 5k?
02-17-2017, 10:32 AM
#11
There are way too many 8.1 nut swingers in this thread.
Did everyone forget they ping like a drunk midget with a hammer on a windchime? Aftermarket is expensive, the bottomends aren't that strong comparatively speaking, and unless you're into custom fab, only short tubes are available
allison requires a body lift
and for an 8.1 to hang with a diesel, must have been a slow, or NA diesel. Everyone of us knows how important boost is, and diesels were bred to run on positive pressure. The only diesels I can see losing to an 8.1 is a 6.5 holocaust or an early NA 7.3
Did everyone forget they ping like a drunk midget with a hammer on a windchime? Aftermarket is expensive, the bottomends aren't that strong comparatively speaking, and unless you're into custom fab, only short tubes are available
allison requires a body lift
and for an 8.1 to hang with a diesel, must have been a slow, or NA diesel. Everyone of us knows how important boost is, and diesels were bred to run on positive pressure. The only diesels I can see losing to an 8.1 is a 6.5 holocaust or an early NA 7.3
02-17-2017, 11:56 AM
#12
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Currently leaning towards a LQ4 block with L92 heads. Cam/Intake suggestions?
Also what would I need to do with the computer? Was figuring everything would pretty much plug right back in, and then need a tune?
Also what would I need to do with the computer? Was figuring everything would pretty much plug right back in, and then need a tune?
02-17-2017, 07:04 PM
#14
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Just to make sure I have all of the info, this is kinda what I was going off of:
Testing LS Cathedral-Port Vs. Square-Port Heads - Hot Rod Network
The stockers only have a 15/ftlb advantage at 3k, but I don't know what its like under that. The L92 hit hard over 4k, more than making up for it imo, but only based on this data. Got any other I can look at?
Testing LS Cathedral-Port Vs. Square-Port Heads - Hot Rod Network
The stockers only have a 15/ftlb advantage at 3k, but I don't know what its like under that. The L92 hit hard over 4k, more than making up for it imo, but only based on this data. Got any other I can look at?
02-18-2017, 11:34 AM
#15
I had a 2005 2500HD with a 6.0 in it and loved it. I kept it basically stock other than a cai, headers and exhaust and it pulled like a mule. I towed my 93 z71 extend cab with it several times and couldn't even tell it was back there. I would have kept the truck but kids came and just wasnt practical anymore.
02-18-2017, 12:03 PM
#16
There are way too many 8.1 nut swingers in this thread.
Did everyone forget they ping like a drunk midget with a hammer on a windchime? Aftermarket is expensive, the bottomends aren't that strong comparatively speaking, and unless you're into custom fab, only short tubes are available
allison requires a body lift
and for an 8.1 to hang with a diesel, must have been a slow, or NA diesel. Everyone of us knows how important boost is, and diesels were bred to run on positive pressure. The only diesels I can see losing to an 8.1 is a 6.5 holocaust or an early NA 7.3
Did everyone forget they ping like a drunk midget with a hammer on a windchime? Aftermarket is expensive, the bottomends aren't that strong comparatively speaking, and unless you're into custom fab, only short tubes are available
allison requires a body lift
and for an 8.1 to hang with a diesel, must have been a slow, or NA diesel. Everyone of us knows how important boost is, and diesels were bred to run on positive pressure. The only diesels I can see losing to an 8.1 is a 6.5 holocaust or an early NA 7.3
It's all dependent on how you tune it. And Some of the ones we ran against were GMT900 trucks...
Body lifts are easy
02-18-2017, 12:59 PM
#17
You're right, we all have opinions and we all stick to them like glue.
l think cost vs performance, a 6.0 swap is the best idea. I've never been a fan of how expensive 8.1 stuff is. Any motor can be made to perform better with money and time. I like how little money and time is needed with the LS platform, comparatively speaking
l think cost vs performance, a 6.0 swap is the best idea. I've never been a fan of how expensive 8.1 stuff is. Any motor can be made to perform better with money and time. I like how little money and time is needed with the LS platform, comparatively speaking
02-20-2017, 01:09 PM
#18
I laugh more than I should have at this. BTW, they still use the 8.1L and a newer stroked out 8.9(9L) variant in natural gas gensets. they put two turbos on the thing and run the hell out of them.
all joking aside. a stock 8.1L vs a Stock 6.6L in pulling: 8.1L will keep up and in some cases excel.
same with a stock 6.0L. but this applies to the older early to mid 00's 6.6L
granted the times it does out do the 6.6L, it's not by leaps and bounds but it does happen. both engines were designed right before the diesel aftermarket really took off. So manufacturers were still trying to have their gassers out perform the diesels.
but the big difference between the three is that the 6.6L will get better fuel economy than the other two while doing literally anything. and then just outing a tune on the 6.6L will leave the other two in dust.
all joking aside. a stock 8.1L vs a Stock 6.6L in pulling: 8.1L will keep up and in some cases excel.
same with a stock 6.0L. but this applies to the older early to mid 00's 6.6L
granted the times it does out do the 6.6L, it's not by leaps and bounds but it does happen. both engines were designed right before the diesel aftermarket really took off. So manufacturers were still trying to have their gassers out perform the diesels.
but the big difference between the three is that the 6.6L will get better fuel economy than the other two while doing literally anything. and then just outing a tune on the 6.6L will leave the other two in dust.
02-21-2017, 09:42 AM
#19
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I think if we were back in 2001 and buying the truck new, the 8.1 would be the obvious choice. Now that you can build a 500+ hp/tq 6.0 from intake to pan for around 4-5k, and something like the raylar stage 1 kit gives 440/490 for that same 4k, its a different ball game.
Im going to do a full compression/leak down test on the 8.1l before I start buying parts but at this point I am 95% convinced it will be a 408. My general plan is something like build the 408, run it for a season while I'm rebuilding the 8.1, then swap again, throw turbo on the 408 and slap it into a track car. My FIL "gave" us a 68 mustang coupe, but only with the expectation that I do a full concourse resto on it. They left the showroom floor with turbo'ed 408's, didn't they?
Im going to do a full compression/leak down test on the 8.1l before I start buying parts but at this point I am 95% convinced it will be a 408. My general plan is something like build the 408, run it for a season while I'm rebuilding the 8.1, then swap again, throw turbo on the 408 and slap it into a track car. My FIL "gave" us a 68 mustang coupe, but only with the expectation that I do a full concourse resto on it. They left the showroom floor with turbo'ed 408's, didn't they?
02-21-2017, 10:12 AM
#20
I got hosed on my initial LY6 purchase, however 408 rotating assembly, machine work and cam I am ~4000 into the motor.
You can find workable blocks for ~$300, heads for ~$4-600 (depending on your head desires) and an intake for ~$200.
I think the 408 is a great choice, but mine doesnt run yet, so I can't speak to the long stroke/ stock deck height issues that ppl have.
You can find workable blocks for ~$300, heads for ~$4-600 (depending on your head desires) and an intake for ~$200.
I think the 408 is a great choice, but mine doesnt run yet, so I can't speak to the long stroke/ stock deck height issues that ppl have.
