GMC Truck Forum banner

1 - 20 of 84 Posts

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #1
I just got word the project is a go! My 2003 Chevrolet Suburban 2500 will be the new Raylar test vehicle for the BBC swap & 540 stroker kit. With your permission, we're planning to post pictures of the build / engine swap here as it moves along.

The current engine in the Suburban is alright for a mouse - 6.0 LQ4 with K&N, Texas Speed 224R on a 114, long tube headers, Spintech 8000 - it lopes nice and runs great, but its not nuts enough.

The 4.5" stroke crankshaft clears within the stock 8.1/496 block to make a 511. We've always had 4.75" stroke crankshafts for the 4.5/4.62 bore motors (604/632cid) and thought, why not turn the stock 4.26 bore motor into a 540cid?

Initial inspection shows that the stock block will require some clearancing for the crankshaft and we may have to use special rods, but everything is a go. If we cannot fit the crank within the stock block, the engine will be a 511cid, but know both Larry and I are planning to make the big cubes work.

8.8/540 - How Much Power?


We aren't exactly sure. In marine applications, we routinely see our 511cid stroker kit produce 650 horsepower and 735 ft-lbs with the BP-206 max effort camshaft and Cool Gap intake manifold.

We're planning to use the lower duration BP-205 high-lift street strip camshaft as we're planning to leave the 4L80E stock and we want this Suburban stock-like driveable. The additional 30 cubes added should produce another 30 more horses, but we're going to use a stock 80mm throttle body and ported Vortec intake manifold instead of the Cool Gap - this vehicle still has to pass California smog. We're expecting to see the limitations of the ported stock intake manifold on this build.

The long stroke means the big increase should be in the torque department. Realistically, we're looking at a crank output somewhere around 630 horsepower / 750 ft-lbs naturally aspirated.

Once we know everything fits in the block, the 540 stroker kit will be another standard off the shelf kit from Raylar. More to come!
 

·
ΜΟΛΩΝ ΛΑΒΕ
Joined
·
8,527 Posts
This should be cool, but are we to expect a stock 4l80e to handle that much power?
As with everything, how much you beat on it will determine how it lasts, a stock engine can wear one out if beat hard enough, but general consensus seems to be 650-700 ftlbs is about the limit on a stock 4l80e's hard parts. I'd say they could make this one live for a while at least. I know several of them surviving 2-300k miles behind a duramax in van applications.
 

·
Registered
Joined
·
1,292 Posts
As with everything, how much you beat on it will determine how it lasts, a stock engine can wear one out if beat hard enough, but general consensus seems to be 650-700 ftlbs is about the limit on a stock 4l80e's hard parts. I'd say they could make this one live for a while at least. I know several of them surviving 2-300k miles behind a duramax in van applications.
Just realize that the max output Duramax's were not used in the 4l80e applications in the vans.
But I agree that a 4l80e would do fine behind this engine.

Thanks Mr Raylar.

peace
Hog
 

·
ΜΟΛΩΝ ΛΑΒΕ
Joined
·
8,527 Posts
Just realize that the max output Duramax's were not used in the 4l80e applications in the vans.
But I agree that a 4l80e would do fine behind this engine.

Thanks Mr Raylar.

peace
Hog
Yes, they are detuned to around 460ftlbs, but we all know how employees treat work vehicles such as that.
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #6
This should be cool, but are we to expect a stock 4l80e to handle that much power?
As with everything, how much you beat on it will determine how it lasts, a stock engine can wear one out if beat hard enough, but general consensus seems to be 650-700 ftlbs is about the limit on a stock 4l80e's hard parts. I'd say they could make this one live for a while at least. I know several of them surviving 2-300k miles behind a duramax in van applications.
Exactly what we're thinking. The Suburban is a daily driver and TH400s are good to about 750-800, so we figure we'll be pushing it but still on the safe side. Of course, after 600 horsepower you start finding all the other weak links in the drive line.

Initially, we're just going to do the 540 stroker / 205 cam / ported intake manifold to show everyone what kind of power can be had with the stroker kit alone. Figure Raylar heads will be added a month or two later, it will be interesting to see how much more power is made with the head swap!
 

·
Registered
Joined
·
763 Posts
Ballpark price of said package after all is said and done?
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #8
Ballpark price of said package after all is said and done?
Not a problem Smurf. We're still waiting on final information on the connecting rods so that might increase the price a bit. We'll probably offer a Raylar truck stage 4 kit which will be a 540cid + Stage 3 kit. The only real differences are the stroke of the crankshaft, piston comp ratio and narrower connecting rods. I used the stage 2 package so pricing it out would be more self explanatory.

Raylar Truck "Stage 2 Kit" with BP205 high-lift cam: $4459
Raylar Ported Intake Manifold: $950
Raylar 4.75 Stroker Crankshaft Kit (estimated): $3350
Estimated Total: $8,759
 

·
TEAM FUEL MOTORSPORTS
Joined
·
7,889 Posts
:hmm:







All this "new" 8.1 info popping up recently and I've just sold the garage queen..... Money in the bank, just sitting there....

:insane2:
 

·
Registered
Joined
·
519 Posts
Our 280K 8.1L dually is getting a bit tired. The 5 speed allison should be a good behind one of these (after its freshened up)
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #11
Minor update: There have been so many questions from the boat guys about modified versions of the stock iron heads (HP2 / HP3) that we decided to start with ported stock heads on the stroker swap. This way you can directly compare ported stock heads versus Raylar aluminum heads for power numbers in a real world application.

How much porting did the heads see? Well, I spent a total of 7 miserable, noisy hours perfecting the stock heads. Thankfully, Larry already has a stock cylinder head cut in half so I could see the thicknesses of intake and exhaust ports before I tore into them.

- The ports were smoothed and slightly reshaped for more straight-line air flow to the cylinder. The intake ports have a extraneous raised section which was cut back quite a bit as well.
- The bowl area was opened up a lot. I removed a great deal of material from the clumsy stock valve guides on both the intake and exhaust ports which impede flow right before entering and exiting the cylinder.
- The bottom of the exhaust port is overly thick on the stock head, I removed about 1/4 inch of material from the bottom of the exhaust ports.

Sorry about the rough pics. I only took pictures of the heads after initial porting, polishing will smooth out any edges.



 

·
( o) ( o)
Joined
·
2,460 Posts
updates?
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #13
I finished cleaning up the stock cylinder heads end of last week.


We outfitted the cylinder heads with our high lift valve spring kit, roller rockers and a set of Viton seals.

The engine block is currently at the machine shop for piston fitment and boring (0.030 over) which will bring the displacement up to 547cid. After we get the block back we'll check connecting rod clearances and start assembly. I will have pics as all of that comes together.



Side note - here's a shot of a customer's 632cid sitting in the shop.
Dart 4.6 bore iron block
4.75 stroker kit
CNC ported iron heads
203 camshaft
stainless steel roller rockers
high lift valve spring kit
90mm Raylar cool gap intake manifold
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #15
Well, it runs so well in the Suburban I figured I would find something neat to shove it into like an old 50s Cadillac..

But, if you cover shipping on it, I figure 2k is pretty fair for a 115k 6.0 LQ4 with cam, dual springs, pushrods and stainless long tube headers. (I will be running stainless works headers on the big block) I've got an extra set of LS7 lifters, lifter trays and head gaskets which I'll throw in as well. I was planning to run heads, but never got around to it.

PM me if you're interested.

In engine swap news, the block is back from the machine shop and the 4.75" crankshaft doesn't drop in. Unfortunately, the 540 kit will not be a simple bolt-in replacement and will require some block modification. Tomorrow, we'll clearance the block for the 4.75" crankshaft. I'll shoot some before / after pictures to show what had to be notched for this kit to fit.
 

·
TEAM FUEL MOTORSPORTS
Joined
·
7,889 Posts
Good to hear of the progress! :thumbsup:


I'll be checking back to watch the build....
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #17
The 4.75" (540cid) stroker kit required some minor clearance work within the stock engine block, but 45 minutes of minor grinding later - everything fits!

To install this kit, you or your machine shop will need to cut about 1/4 inch from the bottom of the inner cylinder walls, focusing mainly on removing the edge near the cam journals. Here are some before and after shots of the engine block, as well as an installed shot of the crank.





 

·
TEAM FUEL MOTORSPORTS
Joined
·
7,889 Posts
Interesting...

I think it's great your taking pics along the way to show this detailed build in depth.... Although I doubt I'd ever have the extra funds to do a similar build on my 8.1, but it's nice to dream! :thumbsup:
 

·
Vortec 8.1L Go Fast Parts
Joined
·
103 Posts
Discussion Starter #19
I think Mercury Racing really got it right with the red valve covers, but the boring flat red needed some street rod flair. I picked up some high temp dupli-color silver / metalcast red candy for the fuel rails / valve covers.





The "candy" metalcast colors come in purple and blue as well. A silver base will give you a more subdued shifting effect, but the more metallic silvers will add even more sparkle. If its too maroon for you, a gold base will add an even warmer glow to the color.
 
1 - 20 of 84 Posts
Top