: 4.9 to 5.7 tbi - what do you think



BigPmpn
05-24-10, 10:13 PM
I have been thinking about how to get more power out of the 4.9, and the thought crossed my mind that I could swap it out for a vortec 5.7 tbi engine out of a 1996-2000 Full Size Truck. I know I would need a tranny adapter for the different bellhousing, but otherwise, what would I be looking at?

Do any motor mounts exist that will work?

Will all the sensors work?

Does anyone know the difference in dimensions between the two engines?

Any info is appreciated. Thanks!

Hogg
05-29-10, 11:58 AM
The 1996-2000 trucks never used a TBI 350, but they did use a CSFI Vortec 305 or 350.
The 1996-2000 Vortec V8's use a different intake manifold that uses 8 vertical bolts, 2 at each corner rather than teh traditional 12 intake bolts. GM Performance Parts makes a Vortec head to TBI intake manifold that allows the 88-95 truck TBI unit to be used on a 1996-2000 Vortec 305/350.

http://www.summitracing.com/parts/NAL-12496821?autofilter=1&part=NAL%2D12496821&N=700+4294822100+115&autoview=sku

peace
Hog

BigPmpn
05-31-10, 06:45 PM
Thanks for the info, Hogg. That will definitely help when I get to that point. This would be a project for next summer most likely, I'm just trying to get a feel for what's involved. My main concern is the overall dimensions of the different engines, I haven't been able to find that info.

If anyone has done anything like this, let me know!

Stingroo
06-06-10, 02:12 PM
What's the torque on the 4.9? That would be really cool. The 350 TBI also is rated at 200 horsepower (I suspect more, though..) and 300 lb/ft of torque.

The Vortec 350's are a bit higher though. I would love to do vortec heads and intake for the wagon... maybe next summer. :(

Rodya234
06-06-10, 02:49 PM
What's the torque on the 4.9? That would be really cool. The 350 TBI also is rated at 200 horsepower (I suspect more, though..) and 300 lb/ft of torque.

The Vortec 350's are a bit higher though. I would love to do vortec heads and intake for the wagon... maybe next summer. :(

The L26 4.9L is rated at 275lb-ft of torque @ 3000 rpm.


The biggest problem I would see is that the 4.9L/4T60-E is a FWD drivetrain, and the 5.7L might not fit into the engine bay mounted transversely. It's pretty cramped in there already.

Stingroo
06-08-10, 07:38 PM
No way. There's a LOT of room under my hood. I assume the Caddy engine bay is just as large.

Not sure on the Eldo though.

N0DIH
06-12-10, 11:52 PM
An LT1 maybe, but not a conventional 350 Small Block, too long, the waterpump/belt accessory drive is too long and sticks out. The LT1 is far more compact there. But the trans will never survive long, the diff is too weak.


No way. There's a LOT of room under my hood. I assume the Caddy engine bay is just as large.

Not sure on the Eldo though.

Stingroo
06-13-10, 12:47 AM
^ Ahoy. Engine master returns. Long time no see around here.

drewsdeville
06-16-10, 11:15 PM
As far as size, also consider the overall width and height of the engines. The 4.9 is surpisingly compact with it's odd geometry (the reason why the 4.9 pushrods go through the intake manifold, not the head) and still it's a snug fit in the FWD engine bays.

I'm going to go ahead and say that 0hp and 25 ft/lbs isn't worth the large effort needed to complete this project.

N0DIH
06-18-10, 01:43 PM
The 350 has of course 10x more go fast goodies than a 4.9 ever will, but you run into weight being more and the trans can't handle it. The 4T65E HD is in the 5.3L FWD SS cars now, which is a nice 303 hp, and very heaviliy torque managed to make the trans live. The diff is the weak link. No wheel spinning! Very important on them, else they explode. The diff is like 6-7 inches. Tiny thing....

Take a stock 210 hp 350 and toss on Vortec heads and a mild cam, and you are way over 300 hp easily. No other changes. Think of it this way, a 5.7L 350 with a LT4 hot cam and vortec heads and good exhaust is a way to make easy 350 hp and still have reasonable street manners. But not in a front wheel drive....


As far as size, also consider the overall width and height of the engines. The 4.9 is surpisingly compact with it's odd geometry (the reason why the 4.9 pushrods go through the intake manifold, not the head) and still it's a snug fit in the FWD engine bays.

I'm going to go ahead and say that 0hp and 25 ft/lbs isn't worth the large effort needed to complete this project.

N0DIH
06-18-10, 01:47 PM
Finally! I am hanging around 3800pro.com and fullsizechevy.com and monodax.com a lot lately, but still lurk around!!! I need to get involved here some more. My Cad is hopefully going to get on the road here shortly again! I miss it a lot. My 3800 SC Buick is ok, but it is no Cadillac. I miss my V8 RWD. Being I am not daily driving it, might go ahead and complete the 9C1 suspension and do some engine mods.... See how much I can do on a 250k mile LT1! I have the 3.42's to put back in and might go with 3.90's.... Ahhh the fun. I want to do a larger cam anyway, the shorter gears really need it. And a looser converter.... I might just go racing and have some fun with a Cadillac Fleetwood!!!



^ Ahoy. Engine master returns. Long time no see around here.

Stingroo
06-18-10, 01:49 PM
I want to get into modding the wagon, both cosmetically and performance wise, and I remembered the vortec heads from your posts here.


Now if only I can find a decent job in this crappy Floridian economy, I would be in business. Good to see you around though.

N0DIH
06-21-10, 11:04 PM
I hear ya! It sucks here, 20-25% unemployment locally here. I was commuting 75 miles each way since 2002 till I got canned last month.

The Vortec heads are vastly superior to the L05 heads, and the cam is ancient grind, so the 2 of them with the decent bottom end the L05 has (truck one would be better given a choice), can make a screamer.

I have sorta got to a point where flow is most important.

But given a budget? I would look to another choice...

Lets see $700 for a upgrade.

Get a $400-$500 LM7 truck 5.3L engine. Starts off with 300 hp.... And more efficient and a bottom end you would have a hard time killing no matter what you did to it.

I'll help out with the PCM tuning for it to keep you in budget if that is what it takes... The new engines are sooo much better....


I want to get into modding the wagon, both cosmetically and performance wise, and I remembered the vortec heads from your posts here.


Now if only I can find a decent job in this crappy Floridian economy, I would be in business. Good to see you around though.