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I played with SBCs for over 50 years, and I can say with full confidence that there is NO comparison between a 400 chp SBC and a 400 chp LT5 when it comes to reliability.
Let me put it another way: It's a damn good thing parts for a SBC are so cheap, because chances are you're gonna need 'em!
Far as the "Torque Monster" goes, Tom said it best: If you have to brag about something, it has to be torque because the L98's 240-250 chp ain't gonna get it! The LT1 will meet the L98s numbers (for all practical purposes).
However, a stock '90 ZR-1 puts both of them to shame - making nearly as much torque at the wheels as either the L98 or the LT1/4 makes at the crank.
If the discussion settles around reliability resulting from modifications being an issue, consider the LT5 can be brought above 500 chp with ZERO addition of performance parts, i.e., ALL stock everything except exhaust - porting and tune alone: Zero reduction of reliability. Zero reduction in driveability, Zero difference in mpg at 70 mph cruise. (In fact, these mods were all validated by the gen-II LT5 originally slated for the 96 ZR-1. According to Graham Behan, a former engineer for LOTUS and now for LINGENFELTER, the 5.7L LT5-II made close to 550 chp. Now, JMO, but how well would a 350 chp C5 stake up against a 550 (NA) chp C4 from the previous year? (Don't strain yourself!)
It has been 8 years and almost 40k miles since I ported my LT5 and installed headers and 3" exhausts - making 432 rwhp. It has been on 4 trips from IL to the Appalachians for the popular Mountain Runs there, Also to Carlisle and back and to Atlanta once and to the Rocky Mts twice (once just this past July) and have ZERO broken LT5 parts; just regular oil changes, tires - routine stuff. And, if the secondary system scares some off as being "complicated", well know that I removed all that back then too - runs on all 16 injectors ALL the time (except @ idle or below 1000 rpm). OK, one example does not a trend make. I get that. So, do some research before dismissing the ZR-1 for your perception of LT5 reliability. (have a look at this source far as parts availability goes: Jerry's Gaskets
My stock 90 (375 chp) LT5 ZR-1 vs. after porting and headers and aluminum FW. And, you might appreciate knowing too that this mod results in so much improved performance with ZERO downside for all practical purposes that it is very popular - many ZR-1s are modded with the "510" package. Believe me, a so modified ZR-1 "sleeper" will do a 45-50 mph 5-2 downshift - putting the LT5 right in its 'wheel house' - and holding it to the floor to 90 mph (still in 2nd gear) will wipe the smirk off a lot of LS faces!
Last edited by Paul Workman; 11-09-2018 at 09:41 AM.
I played with SBCs for over 50 years, and I can say with full confidence that there is NO comparison between a 400 chp SBC and a 400 chp LT5 when it comes to reliability.
Let me put it another way: It's a damn good thing parts for a SBC are so cheap, because chances are you're gonna need 'em!
Far as the "Torque Monster" goes, Tom said it best: If you have to brag about something, it has to be torque because the L98's 240-250 chp ain't gonna get it! The LT1 will meet the L98s numbers (for all practical purposes).
However, a stock '90 ZR-1 puts both of them to shame - making nearly as much torque at the wheels as either the L98 or the LT1/4 makes at the crank.
If the discussion settles around reliability resulting from modifications being an issue, consider the LT5 can be brought above 500 chp with ZERO addition of performance parts, i.e., ALL stock everything except exhaust - porting and tune alone: Zero reduction of reliability. Zero reduction in driveability, Zero difference in mpg at 70 mph cruise. (In fact, these mods were all validated by the gen-II LT5 originally slated for the 96 ZR-1. According to Graham Behan, a former engineer for LOTUS and now for LINGENFELTER, the 5.7L LT5-II made close to 550 chp. Now, JMO, but how well would a 350 chp C5 stake up against a 550 (NA) chp C4 from the previous year? (Don't strain yourself!)
It has been 8 years and almost 40k miles since I ported my LT5 and installed headers and 3" exhausts - making 432 rwhp. It has been on 4 trips from IL to the Appalachians for the popular Mountain Runs there, Also to Carlisle and back and to Atlanta once and to the Rocky Mts twice (once just this past July) and have ZERO broken LT5 parts; just regular oil changes, tires - routine stuff. And, if the secondary system scares some off as being "complicated", well know that I removed all that back then too - runs on all 16 injectors ALL the time (except @ idle or below 1000 rpm). OK, one example does not a trend make. I get that. So, do some research before dismissing the ZR-1 for your perception of LT5 reliability. (have a look at this source far as parts availability goes: Jerry's Gaskets
My stock 90 (375 chp) LT5 ZR-1 vs. after porting and headers and aluminum FW. And, you might appreciate knowing too that this mod results in so much improved performance with ZERO downside for all practical purposes that it is very popular - many ZR-1s are modded with the "510" package. Believe me, a so modified ZR-1 "sleeper" will do a 45-50 mph 5-2 downshift - putting the LT5 right in its 'wheel house' - and holding it to the floor to 90 mph (still in 2nd gear) will wipe the smirk off a lot of LS faces!
Like I said, after some reports reassuring the reliability of the LT5, I'm again considering a 1990 ZR-1. It just needs to be the right price and in the right condition and the right car.
But hearing that the LT5 can be brought above 500 chp with zero addition of performance parts and keep the very same reliability, and hopefully same characteristics including idle, makes it an even stronger candidate. But what costs are we looking at here for this so called "510" package?
510 chp is nothing to sniff at, even in 2018. If I could be successful in getting the car in a diet to lose weight, we would be talking serious challenging performance even to modern sports cars. So let's here more about it please.
Like I said, after some reports reassuring the reliability of the LT5, I'm again considering a 1990 ZR-1. It just needs to be the right price and in the right condition and the right car.
But hearing that the LT5 can be brought above 500 chp with zero addition of performance parts and keep the very same reliability, and hopefully same characteristics including idle, makes it an even stronger candidate. But what costs are we looking at here for this so called "510" package?
510 chp is nothing to sniff at, even in 2018. If I could be successful in getting the car in a diet to lose weight, we would be talking serious challenging performance even to modern sports cars. So let's here more about it please.
Well, here the critics have a point: It is MUCH cheaper to make big power as a rule than it is to modify an LT5 - mitigated somewhat if you have to buy an LS motor as the starter ingredient.
That said, it is possible for a person handy with tools to do a significant amount of the work (e.g., porting) and save 3/4 of the $$ he would spend on a turn-key upgrade. Also, the road to big HP in the LT5 is well traveled. That is to say if you have a HP goal set, it is very possible to plan out a route that will get you there at a pace you control - or as you can afford.
There are too many different options to list here. But, to give you an idea for the kind of performance that is possible and what is involved to get you there, C this link to Marc Haibeck, the ZR-1 Specialist.
My honest opinion would be to DRIVE the ZR-1 stock for a year. Join the ZR-1 Net Registry and get to know the club people and what the car is all about and better understand what if anything you want to change before diving right into it. After a year you will know if you want to keep it as is, sell it and get something else, or bite the bullet and "go for it"!!
Well, here the critics have a point: It is MUCH cheaper to make big power as a rule than it is to modify an LT5 - mitigated somewhat if you have to buy an LS motor as the starter ingredient.
That said, it is possible for a person handy with tools to do a significant amount of the work (e.g., porting) and save 3/4 of the $$ he would spend on a turn-key upgrade. Also, the road to big HP in the LT5 is well traveled. That is to say if you have a HP goal set, it is very possible to plan out a route that will get you there at a pace you control - or as you can afford.
There are too many different options to list here. But, to give you an idea for the kind of performance that is possible and what is involved to get you there, C this link to Marc Haibeck, the ZR-1 Specialist.
My honest opinion would be to DRIVE the ZR-1 stock for a year. Join the ZR-1 Net Registry and get to know the club people and what the car is all about and better understand what if anything you want to change before diving right into it. After a year you will know if you want to keep it as is, sell it and get something else, or bite the bullet and "go for it"!!
Aha! $10K for the 510chp package. Not really sure I want to invest that much, which could be between 1/2 to 2/3 of the price of a good deal on ZR-1 by the looks of it. So either I will have to be happy with the stock 375 of the 1990, or I will go with Mattew's suggestion above in abase C4 1990.
Although maybe it's cheap and simple to at least bring the 1990 LT5 to 405 like the later LT5?
But if I end up buying a 1990 ZR-1 your suggestion is a good one. Drive for a year and see. Maybe I will fall in love with it and not mind investing $10k in the engine alone, then more $$$ in larger breaks to stop the 510hp, plus then chassis stiffening to cope with the 520 hp and so on.
Aha! $10K for the 510chp package. Not really sure I want to invest that much, which could be between 1/2 to 2/3 of the price of a good deal on ZR-1 by the looks of it. So either I will have to be happy with the stock 375 of the 1990, or I will go with Mattew's suggestion above in abase C4 1990.
Although maybe it's cheap and simple to at least bring the 1990 LT5 to 405 like the later LT5?
But if I end up buying a 1990 ZR-1 your suggestion is a good one. Drive for a year and see. Maybe I will fall in love with it and not mind investing $10k in the engine alone, then more $$$ in larger breaks to stop the 510hp, plus then chassis stiffening to cope with the 520 hp and so on.
Well, I did my own porting work, pulled and reinstalled the motor (twice), and I had Pete handle the head machine work and phasing the cams and Marc do the dyno tuning and provide the tuned chip (plus some other nice features). I sent one of the heads to a welder who meant well, but not skilled with repairing a "minor" problem - I ended up replacing the head (an extra $700 cost). There were some complications to work through as well, but frankly all part of the learning curve for a DIY project..
I ended up with a "510" package for under $3.5k (excluding tooling and the head and incidental OE injectors that alcohol had destroyed). Having decades of automotive experience and expert guidance from Marc Haibeck and Pete and Bob Gillig and being able to do a lot of the work myself made my joining the "500" club A LOT less expensive. But, isn't that about normal for a DIY vs. a turn-key project?.
She idles like (well, you've seen the video), and screams like a banshee crossing into the low 7000s at WOT.. It supersizes a lot of "LSx" people and I still have the permagrin from when I first drover her off the lot! And, I'm fortunate to live in the thick of some exceptionally skilled ZR-1 experts: The Fast Boyz of Illinoiz (aka "FBI") club!
Last edited by Paul Workman; 11-09-2018 at 04:33 PM.
Aha! $10K for the 510chp package. Not really sure I want to invest that much, which could be between 1/2 to 2/3 of the price of a good deal on ZR-1 by the looks of it. So either I will have to be happy with the stock 375 of the 1990, or I will go with Mattew's suggestion above in abase C4 1990.
Although maybe it's cheap and simple to at least bring the 1990 LT5 to 405 like the later LT5?
But if I end up buying a 1990 ZR-1 your suggestion is a good one. Drive for a year and see. Maybe I will fall in love with it and not mind investing $10k in the engine alone, then more $$$ in larger breaks to stop the 510hp, plus then chassis stiffening to cope with the 520 hp and so on.
Headers and Marcs chip will get you to 400-410 doing nothing else... And no, you don't need larger breaks nor chassis stiffening.... Weve already established, youre not a race driver, but a street driver.... It seems youve heard allot of these things twice already.... Im not sure what kind of cars youve had in the past, but I can almost be sure a ZR-1 of any year will satisfy your need for the street even in stock form....
Here are some LT5 components weights which I weighed when building my 427 CID engine:
Block (empty) 55 lbs
Lower housing 35 lbs
Crankshaft 60 lbs
Cylinder head (loaded with valves, springs and lifters) 44 lbs
Head bolt set 12 lbs
lower housing and main bearing cap bolts 8 lbs
Last edited by Jagdpanzer; 11-09-2018 at 08:51 PM.
Well, I did my own porting work, pulled and reinstalled the motor (twice), and I had Pete handle the head machine work and phasing the cams and Marc do the dyno tuning and provide the tuned chip (plus some other nice features). I sent one of the heads to a welder who meant well, but not skilled with repairing a "minor" problem - I ended up replacing the head (an extra $700 cost). There were some complications to work through as well, but frankly all part of the learning curve for a DIY project..
I ended up with a "510" package for under $3.5k (excluding tooling and the head and incidental OE injectors that alcohol had destroyed). Having decades of automotive experience and expert guidance from Marc Haibeck and Pete and Bob Gillig and being able to do a lot of the work myself made my joining the "500" club A LOT less expensive. But, isn't that about normal for a DIY vs. a turn-key project?.
She idles like (well, you've seen the video), and screams like a banshee crossing into the low 7000s at WOT.. It supersizes a lot of "LSx" people and I still have the permagrin from when I first drover her off the lot! And, I'm fortunate to live in the thick of some exceptionally skilled ZR-1 experts: The Fast Boyz of Illinoiz (aka "FBI") club!
Isn't the $10K price on the site for the parts only, apart from the porting, excluding labor?
Here are some LT5 components weights which I weighed when building my 427 CID engine:
Block (empty) 55 lbs
Lower housing 35 lbs
Crankshaft 60 lbs
Cylinder head (loaded with valves, springs and lifters) 44 lbs
Head bolt set 12 lbs
lower housing and main bearing cap bolts 8 lbs
Headers and Marcs chip will get you to 400-410 doing nothing else... And no, you don't need larger breaks nor chassis stiffening.... Weve already established, youre not a race driver, but a street driver.... It seems youve heard allot of these things twice already.... Im not sure what kind of cars youve had in the past, but I can almost be sure a ZR-1 of any year will satisfy your need for the street even in stock form....
You're absolutely right.
I actually said I would be happy with 400-ish hp. So I would be happy with a stock LT5. It was just that Paul Workman came in and threw 510 hp out there and made it sound "easy" and or cheap at first. So it picked up my interest. I thought, why not?
But if I buy a LT5 I would be happy with what it gives. If I can bring it up to the 400-ish as the late LT5 even better. It seems just the chip you mentiond already would. But is it possible or even financially worth it to do whatever upgrades GM did to raise the power to 405 in the late LT5? Then maybe chip on top of that. I'm guessing it wasn't only an ECU tuning GM did.
The breaks, chassis etc was just a metaphor for the habit most of us car guys start once you mod the engine. You can never stop only there once you open that door.
Although stiffening up the chassis is something I'm thinking of pursuing in any C4 I buy. Even if I can only notice it when I take it to the track 2 to 4 times a year.
Another thing I will try to do with any C4 I get, especially a ZR-1, even if I don't mod the LT5, or especially if i don't, will be do everything I can to shave weight. If that means upgrading breaks, wheels etc to make it lighter I will. Although I really like 1990 wheels. If it means tossing the electric seats out and replacing them with non electrical C4 seats, I will do that. Or just yank the motors and everything off if all C4 seats are just electric. I even looked at carbon fiber parts like hoods etc and am trying to figure if the weight saving is worth it.
Cutting weight is like adding hp, only better. This is something I will try to do for sure. Carbon fiber is expensive and I'm not sure I will go that far. Especially that I'm thinking the savings over fiberglass wouldn't be as much as if the C4 was made of sheet metal. But throwing things out which are superfluous luxury items, such as electrical seats and a few other things and could make the car lighter, I definitely will do. Especially that this most likely won't add cost or much cost, since it will be basically throwing things away.
I'm guessing for example that the glass roof is heavier than the fiberglass top? So I would go for a fiberglass one. Things like that.
Have people got their road C4s in a diet here? How much weight did you manage to shave?
I say road C4 because in a track car you can naturally throw the whole interior, sound isolation etc in the trash to save weight. But not in a road car.
What can be done to shave weight in a road C4? To be honest the only luxury item I REALLY need is AC. Need no electric seats, electric mirrors etc. Electric windows is probably ok to keep, especially that making them wind up will be difficult. And might not save much weight anyway. But don't need much more than that in luxury. Safety is a different matter. I want the ABS, traction control etc to stay.
Thanks for the chat guys. It has been immensely educative and also fun.
Weight reduction, Headers, remove AIR. remove spare tire and carrier run with half tank of gas.
Really? I'm surprised. Normally glass is heavier. Especially as I think it can't bee too thin glass, for a roof. Or is it not real glass? Is the weight difference known by the way?
What do you mean by headers? Replacing?
By AIR, do you mean air conditioning? I'm asking because you used all capitals.
Spare tire is a good idea. Does the C4 have a full sized one?
Curious to see if people have gone beyond that to shave weight and what else they did.
I actually said I would be happy with 400-ish hp. So I would be happy with a stock LT5. It was just that Paul Workman came in and threw 510 hp out there and made it sound "easy" and or cheap at first. So it picked up my interest. I thought, why not?
But if I buy a LT5 I would be happy with what it gives. If I can bring it up to the 400-ish as the late LT5 even better. It seems just the chip you mentiond already would. But is it possible or even financially worth it to do whatever upgrades GM did to raise the power to 405 in the late LT5? Then maybe chip on top of that. I'm guessing it wasn't only an ECU tuning GM did.
The breaks, chassis etc was just a metaphor for the habit most of us car guys start once you mod the engine. You can never stop only there once you open that door.
Although stiffening up the chassis is something I'm thinking of pursuing in any C4 I buy. Even if I can only notice it when I take it to the track 2 to 4 times a year.
Another thing I will try to do with any C4 I get, especially a ZR-1, even if I don't mod the LT5, or especially if i don't, will be do everything I can to shave weight. If that means upgrading breaks, wheels etc to make it lighter I will. Although I really like 1990 wheels. If it means tossing the electric seats out and replacing them with non electrical C4 seats, I will do that. Or just yank the motors and everything off if all C4 seats are just electric. I even looked at carbon fiber parts like hoods etc and am trying to figure if the weight saving is worth it.
Cutting weight is like adding hp, only better. This is something I will try to do for sure. Carbon fiber is expensive and I'm not sure I will go that far. Especially that I'm thinking the savings over fiberglass wouldn't be as much as if the C4 was made of sheet metal. But throwing things out which are superfluous luxury items, such as electrical seats and a few other things and could make the car lighter, I definitely will do. Especially that this most likely won't add cost or much cost, since it will be basically throwing things away.
I'm guessing for example that the glass roof is heavier than the fiberglass top? So I would go for a fiberglass one. Things like that.
Have people got their road C4s in a diet here? How much weight did you manage to shave?
I say road C4 because in a track car you can naturally throw the whole interior, sound isolation etc in the trash to save weight. But not in a road car.
What can be done to shave weight in a road C4? To be honest the only luxury item I REALLY need is AC. Need no electric seats, electric mirrors etc. Electric windows is probably ok to keep, especially that making them wind up will be difficult. And might not save much weight anyway. But don't need much more than that in luxury. Safety is a different matter. I want the ABS, traction control etc to stay.
Thanks for the chat guys. It has been immensely educative and also fun.
Well, since you seem to be very set on weight reduction, I would buy a base C4 and do what the others have suggested with building an engine to what you want. Dont buy a ZR-1 and start hacking it up to save weight...
11-09-2018, 09:16 AM
goes, Tom said it best: If you have to brag about something, it has to be torque because the L98's 240-250 chp ain't gonna get it! The LT1 will meet the L98s numbers (for all practical purposes).
And, I'm fortunate to live in the thick of some exceptionally skilled ZR-1 experts: The Fast Boyz of Illinoiz (aka "FBI") club!
