SL-C powerplant possibility?
- Thread starter c0wboy
- Start date
I've got a 6.2L L92. I'm going to put fully forged internals and stroke it to a 6.8. I'm figuring 600hp would be pretty easy and ead reliable.
I know it's not the most exotic for sure, but after weighing everything out it was really the obvious choice for me.
- Low cost - I picked up the engine, wire harness, pedal assy, ECU and all Accessories for $2,700
- Lot's O' Power - Will cost about $3.5-$4k to give me 600hp
- Reliable - Easy 200k miles
- Good Mileage - With tall enough gears you can get close to 30mpg.
I'm not giving up on the 180 degree headers,, they sound awesome. I have even thought about doing a dry sump system, that way I can run the headers under the engine. I'll figure out more as time goes on, I'm still stuck overseas for a while longer and won't be till next year before I can start to even work on it (it's just sitting in a garage right now).
I know it's not the most exotic for sure, but after weighing everything out it was really the obvious choice for me.
- Low cost - I picked up the engine, wire harness, pedal assy, ECU and all Accessories for $2,700
- Lot's O' Power - Will cost about $3.5-$4k to give me 600hp
- Reliable - Easy 200k miles
- Good Mileage - With tall enough gears you can get close to 30mpg.
I'm not giving up on the 180 degree headers,, they sound awesome. I have even thought about doing a dry sump system, that way I can run the headers under the engine. I'll figure out more as time goes on, I'm still stuck overseas for a while longer and won't be till next year before I can start to even work on it (it's just sitting in a garage right now).
I'd re-think that - even with a dry smp your exhaust will be hanging well below the frame rails if you run underneath the engine, so you'd have to raise the engine, which means a rear cover, which means probably, what, $10k to make it all work, if not more by the time you're said and done?
Delynn at Griffin Gearboxes informed me he knows someone that is currently working on 180's with a dry sump system, It will require a 3" pan, not the standard 5". I don't remember the name of the system (it was a couple of months ago I talked with him), but said it would work, and the headers could be bought, without the need to fab them up.
Again, it's still so far down the road for me. I'm stuck in Afghanistan (well, not stuck, but I have goals that require me to be here about another year). So my poor SLC will be sitting in a garage for a year before I get to work on it.
Again, it's still so far down the road for me. I'm stuck in Afghanistan (well, not stuck, but I have goals that require me to be here about another year). So my poor SLC will be sitting in a garage for a year before I get to work on it.
^Keep us posted. This may be interesting reading for you....same design.
"Often times I am asked to specify a 180 degree header design, usually for a replica GT40 or Pantera. Though I think it is a great “look” and if I was building a street GT40, would likely choose the design for historical purposes, the truth is, it is often not the best design from a performance standpoint. Why you ask? Engine speed. The V-8s that ran in the late sixties were relatively low rpm engines. Due to packaging, that is, fitting the collectors behind the engine, the shortest primary lengths usually possible is around 36”. This primary length is good for a motor with a useable rpm range of 4500-6000. And wouldn’t you know, a small-block “HiPo” engine of the day made around 300 hp at 6,000 rpm – perfect. Today, some GT40 replica builders fit NASCAR Sprint Cup-derived engines built by the likes of Roush Yates Engines that make power at 8000 rpm+, dictating a header length closer to 28” or shorter. Running a “bundle-of-snakes” header would result in a few ponies left on the dyno room floor.
As the adage goes, “there is more than one way to skin a cat.” Several years ago, Burns Stainless was working with a NASCAR Cup engine builder to develop a 180 degree header (pictures above) that would work with a stock car. The design shown in these pictures was developed that crossed the tubes under the engine. A special dry-sump oil pan was designed for the necessary clearance. Initial testing was promising, but as it goes in racing, rule changes made the header illegal for NASCAR."
Source: Burns Stainless LLC - Bundles of Snakes and 180 Degree Headers
Also, others may chime in, but this sounds pretty great with an x-pipe. Not sure if that is all that is causing the more pleasant sound, but it is pretty nice and may be a good compromise.
http://www.youtube.com/watch?v=5gEVgHLL3Y4
"Often times I am asked to specify a 180 degree header design, usually for a replica GT40 or Pantera. Though I think it is a great “look” and if I was building a street GT40, would likely choose the design for historical purposes, the truth is, it is often not the best design from a performance standpoint. Why you ask? Engine speed. The V-8s that ran in the late sixties were relatively low rpm engines. Due to packaging, that is, fitting the collectors behind the engine, the shortest primary lengths usually possible is around 36”. This primary length is good for a motor with a useable rpm range of 4500-6000. And wouldn’t you know, a small-block “HiPo” engine of the day made around 300 hp at 6,000 rpm – perfect. Today, some GT40 replica builders fit NASCAR Sprint Cup-derived engines built by the likes of Roush Yates Engines that make power at 8000 rpm+, dictating a header length closer to 28” or shorter. Running a “bundle-of-snakes” header would result in a few ponies left on the dyno room floor.
As the adage goes, “there is more than one way to skin a cat.” Several years ago, Burns Stainless was working with a NASCAR Cup engine builder to develop a 180 degree header (pictures above) that would work with a stock car. The design shown in these pictures was developed that crossed the tubes under the engine. A special dry-sump oil pan was designed for the necessary clearance. Initial testing was promising, but as it goes in racing, rule changes made the header illegal for NASCAR."
Source: Burns Stainless LLC - Bundles of Snakes and 180 Degree Headers
Also, others may chime in, but this sounds pretty great with an x-pipe. Not sure if that is all that is causing the more pleasant sound, but it is pretty nice and may be a good compromise.
http://www.youtube.com/watch?v=5gEVgHLL3Y4
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Thanks, josh. I ended up going back to the beginning and found it the other evening. shoulda posted it for everyone. I emailed dan, and he said that he was running 2-3 different cooling mechanisms into the engine bay to keep the porsche transaxle (apparently doesn't like the heat) cool. He also mentioned that he is running a pan under the engine bay which makes me wonder if all would be good if the pan was removed and more airflow reached the engine bay that way???? He also self-fabricated the exhaust too 
Oh, and that engine isn't an LS. FWIW, the LS engines sit a bit higher in the bay too.
I don't think the x-pipe works. Look at the pic above from dan's build and watch that video you posted again....there is a big support area on the SLC where the exhaust x-pipe was on the other car.
Oh, and that engine isn't an LS. FWIW, the LS engines sit a bit higher in the bay too.I don't think the x-pipe works. Look at the pic above from dan's build and watch that video you posted again....there is a big support area on the SLC where the exhaust x-pipe was on the other car.
Yes, I saw that picture taken a while back. That's what prompted me to ask Fran about it, and his exact word's were "Good luck with that."
He said, it was extremely hard to do, as well as there are tons of heating issues from it.
To deviate from the topic slightly (but still relavent), Can SBC exhaust headers work on an LS(x). I know the flanges must be cut and LS1's put on. Other than that, will they fit? The is relavence to this question if it is possible to get them to fit.
He said, it was extremely hard to do, as well as there are tons of heating issues from it.
To deviate from the topic slightly (but still relavent), Can SBC exhaust headers work on an LS(x). I know the flanges must be cut and LS1's put on. Other than that, will they fit? The is relavence to this question if it is possible to get them to fit.
Too much work just to get a sound but to each their own. Just check out this guy:
The whistles go.... whoo whoo! - YouTube
The whistles go.... whoo whoo! - YouTube
Haha, saw that on Tosh.0 a few months ago. Fortunately, I am not going for that tune of an exhaust note.
Thanks, josh. I ended up going back to the beginning and found it the other evening. shoulda posted it for everyone. I emailed dan, and he said that he was running 2-3 different cooling mechanisms into the engine bay to keep the porsche transaxle (apparently doesn't like the heat) cool. He also mentioned that he is running a pan under the engine bay which makes me wonder if all would be good if the pan was removed and more airflow reached the engine bay that way???? He also self-fabricated the exhaust too
I don't think the x-pipe works. Look at the pic above from dan's build and watch that video you posted again....there is a big support area on the SLC where the exhaust x-pipe was on the other car.
Looking at the picture, it looks like it could fit underneath the cross brace. Above still looks like a possibility. I mean even the GTM guys have it, and made by Kooks to boot. :laugh:
I don't think that air filter is very happy, sucking air right above the exhaust, lol!
Looking at the picture, it looks like it could fit underneath the cross brace. Above still looks like a possibility. I mean even the GTM guys have it, and made by Kooks to boot. :laugh:
And its a really good way to burn the bodywork....bubble the paint and generally make you have a really bad day....
Getting heat out of the engine bay as fast as possible is very important...the GT40 guys have realised this ...there are many bubbled paint jobs on GT40's real and replica due to the proximity of the 180 headers to the bodywork...
Getting heat out of the engine bay as fast as possible is very important...the GT40 guys have realised this ...there are many bubbled paint jobs on GT40's real and replica due to the proximity of the 180 headers to the bodywork...
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Howard Jones
Supporter
I built my own headers for my SLC. They are 4 into 1 each side. I read damn near everything I could about header design and came to the conclusion that:
1. Simple is better in a street car, or for that matter a track car that doesn't have to meet any power limiting rules.
2. 1 5/8 to 1 3/4 stepped primary, 30 inches in length into a 3 inch collector for a 6500RPM motor is close enough. In my case this was a good length to fit also.
3. The question of crossover pipe, either X or H, is one that in the end I don't think will work any better than a straight 4 into 1. In order for a X pipe to work you need to have some down stream back pressure in the exhaust system. The back pressure is what the X pipe is used for in order to add exaust flow capacity to overcome the sort of double pulse exhaust in a cross (like ours) normal V8. The install in a SLC just doesn't have enough exhaust system to have much back pressure to overcome.
4. Adding a 16 inch 3 inch diameter crossover pipe from one header collector to the other to reduce back pressure when it is only 25 inches from the end of the exaust system doesn't make much sense and adds a lot of expense, complexity, and heat for what I believe isn't much gain, if any, in power.
5. It would be a bitch to take apart (180 type) and more connections to leak (H or X).
I'm at work so I don't have my pictures here. I will add a picture later and you can see what I mean.
1. Simple is better in a street car, or for that matter a track car that doesn't have to meet any power limiting rules.
2. 1 5/8 to 1 3/4 stepped primary, 30 inches in length into a 3 inch collector for a 6500RPM motor is close enough. In my case this was a good length to fit also.
3. The question of crossover pipe, either X or H, is one that in the end I don't think will work any better than a straight 4 into 1. In order for a X pipe to work you need to have some down stream back pressure in the exhaust system. The back pressure is what the X pipe is used for in order to add exaust flow capacity to overcome the sort of double pulse exhaust in a cross (like ours) normal V8. The install in a SLC just doesn't have enough exhaust system to have much back pressure to overcome.
4. Adding a 16 inch 3 inch diameter crossover pipe from one header collector to the other to reduce back pressure when it is only 25 inches from the end of the exaust system doesn't make much sense and adds a lot of expense, complexity, and heat for what I believe isn't much gain, if any, in power.
5. It would be a bitch to take apart (180 type) and more connections to leak (H or X).
I'm at work so I don't have my pictures here. I will add a picture later and you can see what I mean.
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Ken Roberts
Supporter
The stock stainless LS7/LS9 manifolds are hard to beat. They are hydroformed and surrounded in a stainless cover for heat protection. They can be found for as little as $100 a set.
Will they bolt to any LSx engine???
