8ballautomotive

Hi I'm hoping to get some opinions from those with more knowledge than me. I've just bought an LS3, its fitted with:
- AFR Cathedral port heads #1510
- Texas speed Bald Eagle boost cam 229/242 .600"/.600" 115 LSA 111 ICL
From what knowledge I have this seems like a strange combination. The engine was run naturally aspirated and I intend to keep it NA.
Do you think this is a combination worth persevering with, or should I just start a fresh?
Ideally I want around 550hp and plenty of torque, can i archive this with this set up?
Thanks in advance

jasons69chevelle

What kind of vehicle is it in?
205 heads on a LS3, the low end seems like it would be explosive I’d be interested to see a dyno on that. But yes it does look to be a strange combination.

8ballautomotive

It was in a newer model sierra I believe. Currently it’s on my engine stand but I plan to put it in an OBS K3500

G Atsma

The LS3 never came in any truck. You likely have an L94. Somebody switched heads from the original rectangular port version

8ballautomotive

No it was last fitted to a truck but was out of a corvette originally. Not sure why they would switch to cathedral port heads though but I guess with them being AFR heads they should have decent flow. Also not sure why they would fit a cam intended for boost.

440_Stroker

Maybe random used parts purchased individually in an effort to save money? Maybe the idea for low end power was the goal in a heavy vehicle.

grinder11

iTrader: (1)

It sounds like it would make for a nice truck motor. 205 cathedrals would have good low end, and still have decent high rpm power. Are they CNCd 205s?

old motorhead

iTrader: (10)

Yep, I'd run it. You can move around where it makes power with different cam timing, but the cam you have is healthy enough to make some decent power. 550 engine HP may be doable with a decent intake manifold. If it's an SBE LS3, your static CR will be up a little.

Utinator

If it's going into a truck, I would swap the cam while you have it on a stand. A smaller cam will make power lower in the rpm range. With the cam you have now, it's going to want to rev real high. It sounds like they planned on using a short runner intake with a turbo on this engine.

I would go with something in the 224/232-114 (.600) area for good low end power and still be over 550hp at the crank. A cam this size will probably still make peak torque and hp around 5000 and 6000 rpms. You could probably go a little smaller if you want to peak sooner.

A cathedral port FAST-102 would be a good intake option, but the TBSS intake would work too.

NAVYBLUE210

RonSS put AFR 205s on LS3 shortblock with FAST 102 and 226/230 cam,
went 10.90s @ 126+ in a C5.

+2-6* max exhaust split is the sweet spot on those heads NA
(with a good header & exhaust system).

+13* exhaust split is Way to big for those heads NA.

8ballautomotive

I think I’ll stick it in ‘as is’ for now and see how it runs. I have two other trucks, one with a 6.0 steel block and one with an aluminium 5.3 both with 317 heads so I’ll maybe swap the AFR heads on to one of those at some point.

G Atsma

Haven't heard of a steel block. Lots of cast iron ones though....
One is not the other...