2012 RCR #2 Allow use of 5.3L LS motors in place of 5.7L LS

[Al F.]

Two different RCRs came in effectively for the same thing so I combined them. Here is their text:

 

Rule reference # 7.11 Engine

Recommended Revised Wording;

7.11.1

Any 4.6 Ford, 5.0,(302 Ford or 305 GM), 5.7 liter LT1 GM V8 production engine, in OEM stock configuration unless otherwise stated in these rules, that was originally offered in an eligible model car is legal. Cobra R model engines (Ford) and LT4 (GM/Chevrolet) engines or engine components are prohibited. Any Chevrolet LS series 5.3 liter engine from 1999 - 2004 (Iron or Alum.) may be substituted for the LS1 engine package on the 1998-2002 F body that came with an LS1. Or installed in any 93-02 GM F-body. If the Iron block 5.3 is used the 50 lbs weight penalty is negated.

 

Reasoning for change :

the 5.3's are significantly cheaper than the LS1. LS1's in need of a rebuild typically cost between $1000 and $2500 depending on where your lookin. Then a typical Rebuild is $1500 +/-. An LS1 from a wrecked car with low miles will run anywhere from $2000 to $4000. And sometimes $5k + with the T56 6 speed. The LS series 5.3 iron block versions will cost anywhere from $300 to $1500. A $1500 5.3 will be a pristine low mileage engine. The availability of the 5.3 are endless, the aluminium block 5.3 was available from 2002-2004 on GM trailblazers and Buick Rainier's and some (Pick Ups) while not as common are also readily available and inexpensive. The difference between the 5.3 and the 5.7 LS1 is only the bore size. The LS1 bore is 99mm (3.898in) and the 5.3 is 92mm (3.78in). Heads, crank , rods, all external accessories are interchangeable. The relationship between the 5.7 and the 5.3 is the same relationship as the 350 and the 305 that is currently allowed in the rules today. The 5.3 is GMs bread and butter truck V8 engine and has been installed in literally Millions of GM trucks, vans and SUVs.

 

---------->a) Willl decrease series cost because…

of the low cost and availability of these modern day engines. The expense of the LS1 can cause some potential competitors to turn away. If you wanna keep CMC cheap and grow the class we are gonna have to deal with the escalating cost of the LS1 eventually...

 

---------->b) Will increase driver safety because…

NA

---------->c) Will promote series growth because...

We can convert alot of the bazillion 98-02 V6 F-body's to CMC because they are cheap and the same as the V8 cars except they are missing the V8. Hell, the T5 that came in these V6 cars might also work with the 5.3 truck motors so it will even save us more $$$$. We have a potential CMC'er in RMR that bought one of the many SCCA SSB 98-02 Camaro's. He just needs a V8 and he'll be in CMC. If the 5.3 was legal I'd have him out of that V6 and into CMC in no time. I know there are more of those SCCA SSB F-body's out there that aren't competitive in SCCA SSB anymore and thats not even figuring the mass exodus of people from SCCA to NASA.

*NOTE* (I've got my eye on a $1000 2001 Camaro V6 5 speed. If I can get my hands on one I'll know more about the 5.3/T5 combo)

 

---------->d) Will improve competition because…

competitors will not have to sacrifice running a worn out engine or missing events because they are saving to replace / rebuild there LS1 or LT1. I know if I vented my LS1 mid-way through the season I'd be done for the year, but If the 5.3 was legal I could probably tip over the furniture to scrounge enough to get a used 5.3 out of a wrecked truck. I think Cody bought one for $600?

 

---------->e) Will provide more clarity because...

"The 350 and 305 are in the rules today and the 5.7 and 5.3 is the modern day relationship. This will provide consistency in the rules."

 

 

 

2) Rule reference:

7.11 Engine

3)

Recommended wording:

7.11.1

Any 4.6 Ford, 5.0,(302 Ford or 305 GM), 5.7 liter LT1 GM V8 production engine, in OEM stock configuration unless otherwise stated in these rules, that was originally offered in an eligible model car is legal. Cobra R model engines (Ford) and LT4 (GM/Chevrolet) engines or engine components are prohibited. Any LS series 5.3 liter engine from 1999 - 2004 may be substituted for the LS1 engine package on the 1993-2002 F body. If the Iron block 5.3 is used the 50 lbs weight penalty is negated.

4) Will decrease series cost because the 5.3 is a fraction of the cost of a LS1. LS1 needing rebuilt typically costs between $1000 and $2500 depending on region. A LS1 from a wrecked car with low miles will run anywhere from $2000 to $4000. The LS series 5.3 iron block versions will cost anywhere from $300 to $1500. A $1500 5.3 will be a pristine low mileage engine. The availability of the 5.3 is endless. the aluminium block 5.3 was available from 2002-2004 on GM trailblazers and Buick Rainier's while not as common are also readily available and inexpensive. I Purchased one with 69K miles for $700. This engine as a LS1 would have cost around $2500.

The difference between the 5.3 and the 5.7 LS1 is only the bore size. The LS1 bore is 99mm (3.898in) and the 5.3 is 92mm (3.78in). Heads, crank , rods, all external accessories are interchangeable. The relationship between the 5.7 and the 5.3 is the same relationship as the 350 and the 305 that is currently allowed in the rules today. The 5.3 is GMs bread and butter V8 and has been installed in literally Millions of GM trucks, vans and SUVs.

See the attached link to Car-Part.com and you can see the price and availability of these engines in your area.

http://www.car-part.com/ Use 2000 Chevy Silverado 1500 for a sample search and it brings up 28 pages of available engines....

 

Will increase driver safety because: NA

 

Will promote series growth because:

of the low cost and ease of availability of these modern day engines. The comparative difficulty to procure and expense of the LS1 and even the LT1 can cause some potential competitors to turn away.

 

Will improve competition because:

competitors will not have to sacrifice running a worn out engine or missing events because they are saving to replace / rebuild there LS1 or LT1.

 

Will provide more clarity because:

The 350 and 305 are in the rules today and the 5.7 and 5.3 is the modern day relationship. This will provide consistency in the rules.

[raybob92891548534723]

This will be a great addition to the Rules. Theres a zillion 5.3's out there.

I got a V6 Car waiting to be converted...

[wastntim]

having just spent a ton of money on a rebuild of my LT1 only to have it not be right, I am for any option which would cut costs down in the future.

[nape1548534725]

having just spent a ton of money on a rebuild of my LT1 only to have it not be right, I am for any option which would cut costs down in the future.

 

You might want to submit a RCR to allow them in 3rd gens then. As of right now, 4th gens only.

[wastntim]

having just spent a ton of money on a rebuild of my LT1 only to have it not be right, I am for any option which would cut costs down in the future.

 

You might want to submit a RCR to allow them in 3rd gens then. As of right now, 4th gens only.

 

Good Point.

 

Then again who says I'm going to be driving a third gen?

 

Just kidding. Cindy will have me living in my truck before she let's me spend any more money on racing.

[ls168camaro]

The LT1 bolts into the 3rd gen from my understanding but the LS1 doesn't. The LS1 requires a subframe change for the 93-96 F-body.

 

This has been discussed on here before. The 5.3 would be great and a no brainer. Has to be similar to the 5.0 guys being able to run short blocks from all the exloders out there.

 

The 5.3 shortblocks are available everywhere. Only difference would be the bore then I could throw in the LS1 cam, heads, intake, etc. as everything is interchangeable. Would save an easy $2k from a rebuild and allow more people to build them out of v6 cars.

[MHISSTC]

In the Mustangs, and depending upon the vintage, there are differences between the V6 and V8 cars in things like the driveline, brakes, and suspension components, and computers/wiring harnesses that need to be swapped out when converting a V6 (or I4) to a V8. Out of curiosity and since I am not as familiar with the GM products, what are all of the differences between the V6 and the V8 GM cars that need to be swapped out to complete the conversion?

 

I figure the cars you are planning on building are full-tilt-boogie CMC cars and not just merely "legal" cars, so I'm guessing several of the components that would have to be swapped when converting from V6 to V8 are going to be upgraded with aftermarket pieces anyway. Neglecting the purchase price of the subject car for a moment, what would the price difference be to build a top shelf '98-'02 GM CMC car if you started with a running/driving V6 manual transmission car versus a V8 manual transmission car with a blown engine if you figure on building the car with an iron block 5.3L and 6 speed?

 

Is the only difference between the late and early 4th gen cars in the above scenario the front subframe unit?

 

Since the 3rd gen has already been mentioned, am I correct in assuming the number of changes needed would be much more numerous and costly? Does it require the same subrame swap to run the 5.3L, or is it out of the question?

[Adam Ginsberg]

Has to be similar to the 5.0 guys being able to run short blocks from all the exloders out there.

 

For clarification - the 5.0L engine from the Explorer SUVs (just the long block, not the controls) is identical to the 5.0L engine Ford used in the Mustangs, as well as the F150 pick trucks. Same block, crank, rods, pistons. Ford used GT40P heads, and, IIRC, regular GT40 heads on the Explorers.

 

So, let's not muddy the waters regarding the discussion about the RCR for the 5.3L GM engine by saying it's the same thing for the Fords. It's not, so please keep it out of the discussion.

[Glenn]

Has to be similar to the 5.0 guys being able to run short blocks from all the exloders out there.

 

For clarification - the 5.0L engine from the Explorer SUVs (just the long block, not the controls) is identical to the 5.0L engine Ford used in the Mustangs, as well as the F150 pick trucks. Same block, crank, rods, pistons. Ford used GT40P heads, and, IIRC, regular GT40 heads on the Explorers.

 

So, let's not muddy the waters regarding the discussion about the RCR for the 5.3L GM engine by saying it's the same thing for the Fords. It's not, so please keep it out of the discussion.

 

It is the same since the only parts being swapped are the short blocks. The only difference is the displacement - the proposed motor is SMALLER.

[Adam Ginsberg]

It is the same since the only parts being swapped are the short blocks. The only difference is the displacement - the proposed motor is SMALLER.

 

You just proved my point - it's not the same.

[Glenn]

So you would be against the Explorer motor if it was .4ltrs smaller?

 

All these years of listening to Fords guys complain about the GM's having a 350 (5.7ltr) and here we are willing to drop in iron 5.3's in place of aluminum 5.7's and your against it.

 

Obviously I'm only for it if does not prove to be an advantage performance wise. Surely you realize it will be tested prior to approval - right?

[D Algozine]

Bob suggested this last year, and I thought for sure it would be have been approved. But when it wasn't, I was surprised.

What would be the reason for not allowing the 5.3? I really cant think of anything.

Its cheaper

More widely available

No performance advantage

Same design as an LS1

Potential to grow the series

 

Really, what is the down side?

[raybob92891548534723]

Really Adam? Its the same as an LS1 except less displacement and 9 out of 10 of them are Iron Blocks.

This IS a No Brainer.

 

1.)About the same or less power

2.)Interchangable with LS1

3.)More of them available

4.)Much more affordable

 

Why would anybody in their right mind be against this?

[Adam Ginsberg]

It's always interesting how people put words in others mouths, and things turn into a train wreck.

 

Did I, in either of my posts, state I was, or was not, in favor of the proposed allowance of the 5.3L GM LSx engine? No, I didn't.

 

I said not to muddy the waters with incorrect information when we consider the 5.3L GM LSx engine. It was in response to Bryan's thought that "it has to be similar to using the 5.0L from the Explorer". It's not the same situation, because the Explorer 5.0L engine is exactly the same as the 5.0L Mustang engine.

 

Doing things like that is precisely how these threads turn into a useless waste of time and effort. Let's stay focused on actual accurate tech, and not bits of outright wrong information that don't belong in the discussion.

 

Infer whatever you wish. I'm not going to debate the potential 5.3L allowance here.

[Glenn]

Bob suggested this last year, and I thought for sure it would be have been approved. But when it wasn't, I was surprised.

What would be the reason for not allowing the 5.3? I really cant think of anything.

Its cheaper

More widely available

No performance advantage

Same design as an LS1

Potential to grow the series

 

Really, what is the down side?

 

Lack of data last year. It is possible it was submitted too late. I'm not sure though.

You are correct on your points made above. Should be a slam dunk.

[CMC#11]

Bob suggested this last year, and I thought for sure it would be have been approved. But when it wasn't, I was surprised.

What would be the reason for not allowing the 5.3? I really cant think of anything.

Its cheaper

More widely available

No performance advantage

Same design as an LS1

Potential to grow the series

 

Really, what is the down side?

 

Lack of data last year. It is possible it was submitted too late. I'm not sure though.

You are correct on your points made above. Should be a slam dunk.

I'm reading into your text but I get the feeling that if this rule doesn't get changed, you will be overly shocked.

There are lots of RCR's that have been submitted by racers who I'm sure felt it was a "slam dunk" and then nothing changed. My head spins every year at some of the decisions made to the point that nothing surprises me anymore.

 

FWIW, with being able to learn a little more on the 5.3 vs 5.7 I'm pretty certain I'd be on board with the change.

[Glenn]

The power band is a place to be worried about. This will depend on how much restriction (if any) is needed.

Also, do we allow the whole long block, or just the short block? Truck cam? The intake from the truck will not fit under the 4th gen hood.

 

My thinking is - test the longblock as is, and then go from there. Cam swaps on LSX motors are very easy. Don't even need to remove the intake or lifters.

[Steve91T]

Any idea of what might be involved to swap the LS 5.3 into a LT1 4th gen? Obviously LS T-56, but what about engine mounts? Does it bolt in?

[Glenn]

Any idea of what might be involved to swap the LS 5.3 into a LT1 4th gen? Obviously LS T-56, but what about engine mounts? Does it bolt in?

 

The K members are different from LS1 and LT1. Motor mounts are also completely different. Obviously you will need a 4th gen LS1 PCM and electronics, wiring. Some sensors may also be different.

The LT1 T-56 will need a different input shaft and front cover plate as well as a different bellhousing. Also the clutch is hydraulics are totally different. The rack is different as well for the LS1 cars. The stearing shaft inputs to the rack at a different place and different angle due to the alt position on the LS1 motor. And of course the accesories on the front are totally different. The radiator should work on either. Upper radiator plate on the LT1 will need to be swapped w/ one from an LS1 car since the LS1 uses that part as the lower airbox housing.

Gotta know your 4th gens if you want to do a swap. Likely some of the same issues for a V6 to LSx swap.

[Al F.]

I'm not sure its such a slam dunk, though its certainly worth looking into. Its entirely reasonable to expect that the 5.3 will have both peak and power under the curve numbers inferior to the 5.7, but until we prove it then we're just assuming. I'm not approving it until proven, but I am willing to work with the guinea pig to ensure he doesnt get hurt.

 

There are quite a bit of technical aspects to work out including is it only the block and pistons, or does it also need to run the 5.3 head otherwise the compression falls appart, does the 5.3 intake work or do you have to run the 5.7 intake...lots of details, but nothing insurmountable.

[Glenn]

Has to be similar to the 5.0 guys being able to run short blocks from all the exloders out there.

 

I'll have to respond to this comment to get my point across.

If you mean similar w/ regards to a cheaper altermative to an OEM motor, them yes it is similar.

[ls168camaro]

Has to be similar to the 5.0 guys being able to run short blocks from all the exloders out there.

 

I'll have to respond to this comment to get my point across.

If you mean similar w/ regards to a cheaper altermative to an OEM motor, them yes it is similar.

 

Correct. It is similar to the 5.0 guys having a cheap and plentiful alternative from all the other applications it came in.

 

I agree with Al that there are items to address but it isn't that complicated since everything bolts onto the 5.3.

Off the top of my head I would suggest requiring a factory F-body intake manifold. No biggie since they are cheap with everyone going to other intakes.

Same thing for the camshaft. Be aware there were 2 different cams that came in the LS1 F-body. The 00-02 cam is commonly referred to as the truck cam as its the same came used in tons of trucks. I don't know the exact specs on each 5.3 cam but changing the cam would be easy.

F-body heads can be had for $100 any day of the week. I don't know the compression ratio change if swapping the heads but with how similar the heads are you probably don't even need to swap them. Just throw on the intake system and maybe swap the cam if its different.

 

I haven't seen any evidence presented that this shouldn't be given a chance other than its a smaller motor.

[ls168camaro]

So what happened to all of the posts over the weekend? Why do the mods always have to come in and delete posts made by Adam when he goes crazy over Glenn and me? It's been pretty clear over time that Adam goes way out of his way to try and slander Glenn and to a lesser degree myself.

Why does Adam and maybe other directors not want to be transparent? This is a small group of people and the ones setting the rules are also racers so seems logical in America to make these sort of things public. Even in our government we get to see how our elected officials vote so why is this so much different.

I know-I'm beating a dead horse and this comes up every year or two. I'll just go start another thread about transparency.

[Glenn]

Truck intake will not fit under the hood.

[MHISSTC]

I haven't seen any evidence presented that this shouldn't be given a chance other than its a smaller motor.

 

As I understand it from the GM dudes who I've heard extolling the virtues of the LSx engines, the smaller displacement should work out better because it won't have to be choked down with an itty bitty restrictor plate like the LS1.