BAD WAG build

It has been over a month since your last post, anything new?

BAD WAG was at the 2024 ISSCA Nationals photographing the events. Incredible photographer. I'll be sharing some of his work in a related thread here soon.

Fred Kiehl wrote:

It has been over a month since your last post, anything new?

Hey Fred, thanks for checking in.  I've been busy with other family stuff, traveling, and July was the hottest month on record.  Almost every day it was between 110-120 degrees, too hot to work outside (even though I have a RV cover) on the car.  But, I did get the new oil pan installed on the engine.  I tried to get the engine in the car, but I couldn't get it done.  I could only get one side mount bolt in, just couldn't get the other to line up. I pulled the engine out four times and retried but doing it by myself was impossible for me.  On this past Saturday had four of the car club guys come over and we got it in.  Engine sits perfect, plenty of room from the crossmember and brake line.  Starting in a couple weeks the temps shout be cooling off and I should be able to get out there and working on it more.

sherlock9c1 wrote:

BAD WAG was at the 2024 ISSCA Nationals photographing the events. Incredible photographer.  I'll be sharing some of his work in a related thread here soon.

Truth! I still have a LOT of pics to edit and post, many more of your car!

for what it is worth, I watched an episode of Engine Masters today, and they were testing tunnel ram intakes. They found that the A/F ratios varied widely from cylinder to cylinder. They asymmetrically rejetted the carbs, and got them within reasonable A/F ratios. They did it on a dyno with O2 sensors in all eight primary tubes. Consider having your engine set up on a dyno before putting it in service. One cylinder was at fourteen to one, and that is enough to melt a piston.

Fred Kiehl wrote:

for what it is worth, I watched an episode of Engine Masters today, and they were testing tunnel ram intakes. They found that the A/F ratios varied widely from cylinder to cylinder. They asymmetrically rejetted the carbs, and got them within reasonable A/F ratios. They did it on a dyno with O2 sensors in all eight primary tubes. Consider having your engine set up on a dyno before putting it in service. One cylinder was at fourteen to one, and that is enough to melt a piston.

I agree with Fred, tunnel rams are tough to tune, and from what I have seen of them in the past even finely tuned they still have mixture issues.

Tunnel rams are made for high rpm and high load and usually have carbs that are similarly large flow.  Most don't run well at low rpms and loads due to low airflow, poor atomization, and fuel drop out.  The have long runners that run cold so makes drop out quite bad and worse on the front cylinders than the rear.  When carbs are jetted, they really only work well over a narrow range of rpm and power as that is just the nature of carbs and venturi fuel deliveries. When you look at modern engines, and our LT1s are the prototype for a lot of them at GM, you see shorter runners that are no bigger than necessary to make the power needed and determined by the rest of the engine design.  Chrysler had very similar engines in the late 90s with the first Magnum engines.  They had short, small diameter, runners and small ports to matching flow valves and were way ahead of their time, I think.  It was quite easy to get 350hp out of a 318 with a carb or throttle body injection back then with the stock intake and "302" tiny port, fast flow, heads and streetable cam that made them very driveable.

Of course none of this stuff has visibility factor that a tunnel ram and dual carbs has

Fred Kiehl wrote:

for what it is worth, I watched an episode of Engine Masters today, and they were testing tunnel ram intakes. They found that the A/F ratios varied widely from cylinder to cylinder. They asymmetrically rejetted the carbs, and got them within reasonable A/F ratios. They did it on a dyno with O2 sensors in all eight primary tubes. Consider having your engine set up on a dyno before putting it in service. One cylinder was at fourteen to one, and that is enough to melt a piston.

Great info Fred! That's really interesting how it was that different. I'll look into it more. Thanks!

booster wrote:

Fred Kiehl wrote:

for what it is worth, I watched an episode of Engine Masters today, and they were testing tunnel ram intakes. They found that the A/F ratios varied widely from cylinder to cylinder. They asymmetrically rejetted the carbs, and got them within reasonable A/F ratios. They did it on a dyno with O2 sensors in all eight primary tubes. Consider having your engine set up on a dyno before putting it in service. One cylinder was at fourteen to one, and that is enough to melt a piston.

I agree with Fred, tunnel rams are tough to tune, and from what I have seen of them in the past even finely tuned they still have mixture issues.

Tunnel rams are made for high rpm and high load and usually have carbs that are similarly large flow.  Most don't run well at low rpms and loads due to low airflow, poor atomization, and fuel drop out.  The have long runners that run cold so makes drop out quite bad and worse on the front cylinders than the rear.  When carbs are jetted, they really only work well over a narrow range of rpm and power as that is just the nature of carbs and venturi fuel deliveries. When you look at modern engines, and our LT1s are the prototype for a lot of them at GM, you see shorter runners that are no bigger than necessary to make the power needed and determined by the rest of the engine design.  Chrysler had very similar engines in the late 90s with the first Magnum engines.  They had short, small diameter, runners and small ports to matching flow valves and were way ahead of their time, I think.  It was quite easy to get 350hp out of a 318 with a carb or throttle body injection back then with the stock intake and "302" tiny port, fast flow, heads and streetable cam that made them very driveable.

Of course none of this stuff has visibility factor that a tunnel ram and dual carbs has  

I understand all that and have researched the different aspects of a tunnel ram. A friend of mine who is a retired engine machinist/builder when I told him I'm going to use a tunnel ram his first reaction was I can get a lot more power with a different intake. Which of course I agree with. But, my purpose of this built is a street cruiser, not looking for max power (I have my 95 Impala race car for that). And like you said the visibility factor of a tunnel ran / dual carbs sticking up out of the hood is impressive.

Now that I have the engine back in, time to start putting things back together. I installed the radiator support today.

 

Fred Kiehl wrote:

BAD_WAG wrote:

Fred Kiehl wrote:

BAD_WAG wrote:

Will do, good info.  This is a challenge, I wish I had access to different headers to test fit!  

That would be nice. No matter how nice they look, if they don't fit in the car, you can not use them.

I think you should have 2 inch ID primary tubes. Less than that and you are causing flow issues. If you want the most performance, learn the aerodynamic rules and follow them. Make sure the intake and heads are gasket matched too.

Agree, good catch by you on the other ones I have.  I guess I just had a brain dump and didn't even think to look at the size of them.  They fit the stock cast heads, but I bought bigger AFR heads.  I do need to refresh my memory on this stuff.  Haven't had to think about a lot of this building stuff in a long time.  Damn old age...

2 inch is best, although when I found these 1 7/8 is pretty damn close.  Decisions, decisions...

1 7/8 is still smaller than the 1.93. I would not use them.  You really need the 2 inch tubes.

I contacted AFR Tech Support and they recommended 1 7/8 tube headers.

BAD_WAG wrote:

Fred Kiehl wrote:

BAD_WAG wrote:

Fred Kiehl wrote:

BAD_WAG wrote:

Will do, good info.  This is a challenge, I wish I had access to different headers to test fit!  

That would be nice. No matter how nice they look, if they don't fit in the car, you can not use them.

I think you should have 2 inch ID primary tubes. Less than that and you are causing flow issues. If you want the most performance, learn the aerodynamic rules and follow them. Make sure the intake and heads are gasket matched too.

Agree, good catch by you on the other ones I have.  I guess I just had a brain dump and didn't even think to look at the size of them.  They fit the stock cast heads, but I bought bigger AFR heads.  I do need to refresh my memory on this stuff.  Haven't had to think about a lot of this building stuff in a long time.  Damn old age...

2 inch is best, although when I found these 1 7/8 is pretty damn close.  Decisions, decisions...

1 7/8 is still smaller than the 1.93. I would not use them.  You really need the 2 inch tubes.

I contacted AFR Tech Support and they recommended 1 7/8 tube headers.

If they say it is OK, I am not going to argue with them. Do whatever you want.

You should watch the episode of Engine Masters dealing with header primary tubes. I believe they agree with my pick. Unless you have a long taper, you will have an aerodynamic trip edge that will cause turbulence in the pipe.

I agree with what you are saying and I am looking for to getting a 2 inch setup.  

But, for the sake of discussion a 1 7/8 tube is pretty damn close.  That means (if I'm correct) that trip edge will be 1/16 which I don't believe is hardly significant with my setup.  I have watched car show episodes where they compare headers with the tubes compressed (so they fit the car, and show no significant loss in power compared to a non-adjusted header tube.  Which, honestly, surprised me with the results. I can completely understand with my original headers that were 1 3/4, that was a big trip edge.   A top fuel 3000hp setup, sure they squeeze everything they can to make power.  My setup, 600ish hp, I don't think there would be a significant loss in HP.  

But, again, I'm looking at 2 inch primary tube headers to buy.

Finally got the solution to a transmission crossmember for the wagon. Thanks to a fellow B-Body owner (Chris Belcher) for letting me know about BRP Hot Rods as they sell universal crossmembers. Mainly for LS conversions, but they have them for TH400 in the B-Body. The only issue I ran into is the frame on a wagon is different than a sedan, which BRP didn't know. Reference the pic from their installation guide, on a sedan the drivers side main part of the frame stops just aft of the bolt holes for the crossmember. On a wagon the frame continues aft. On their installation guide they have you drill a couple holes and use an adapter bracket to stabilize the bracket. On a wagon this is not an option. So I will see how it holds, if I need to I can drill a hole in the frame and install a bolt or tack weld the bracket to the frame at the rear of the bracket. Which seems the easiest to do.

Below second from BRP installation guide. Ref the frame stopping aft of the two forward bolts and the adapter bracket on the aft section of the bracket. Not an option on a wagon.

Must not have any old heads working there to not know the wagons are different.

Whenever I see the replacement crossmembers for our cars I wonder about the strength of them compared to the massive factory crossmembers.

The cars are body on frame with a parallel rail frame so the crossmember, as far as I know, would be structural and needed to maintain the frame strength.

Has anyone ever heard anything about that topic?