LT193

So i know that they are alot smaller in displacement but does anyone know if they are more efficent of a motor? Cause that also adds power as we all know. I was wondering what anyone also thought about the matchup NA vs NA and booste VS Booste. I think the GM LS line holds the king for NA vs NA. But i think the booste part is a bit different. If anyone would like to compare and have Friendly conversation about the 2 please reply with some good stuff.

GhostZ28

Yeah I'm pretty sure GM did the old pushrod V8 better than anyone else and it holds up to the modular fords very well. I think the only reason for a modular motor is.... repair.. wait... cost of.. wait.. what are the benifits?

LT193

Well first some of the advantages they do have over our motors.
1: no noise at idle and smoother running engine.
2: better gas milage in stock trim and modified trim.
3: less maintanance when it comes to the valve train.
4: Less compression stock which enables better boosting.
5: Overhead cam ability which enables high RPMs.

Advantages of LS1 motor
1: Cubic inches over fords modular 346 to 281.
2: more compression to help the NA guys (like me)
3: Great flowing heads and intake, unlike a mod motor an ls1s intake flows well.
4: Great bottom end that is probably stronger then your adverage 281 Gt motor (unless compared with cobra motor)
5: more aftermarket and cheaper parts.

These are some things i can think of right off hand, although i must say a 4 valve head on a cobra motor makes exceptional flow over an LS1 head. I have seen 320 CFM out of a 4 valve head, and i know that it is capable of more. This is a limiting factor with LS1s, even know they flow almost as well with half the valves i dout that they could ever flow as well as a 4 valve head. Anyone have any ideas yet?

mmmchickenboy

two intake valves are in the works

LT193

Anyone have any more take on this?

downwithmustang

Yet I would like to know as well. Those 4.6L can get alot of boost (I think around 20psi) over the 5.7L. The 4.6L has an cast lron over the 5.7L aluminum.

downwithmustang

Here goes some information on the 4.6L http://www.modularfords.com/articles...aration/1.html The cast iron was made for nitros and supercharged as for the LSX was not because of it being aluminum.

Ken S

better gas milage? I guess that would also depend on the car around the engine too.


Also the dohc mod engines are physically much much larger than a LSx engine.. and weigh in more. The LSx family may displace more ci internally, but they are lighter and smaller overall in physical dimensions.


Packaging is one major advantage about the V8 pushrod (cam in block) engine that most people don't realize. They don't understand that even though it displaces more internally, its most likely smaller and lighter physically overall to a comparable DOHC engine.

Even compared to turbo applications (intercooler, piping, turbo, etc)

NavyBlueFanatic

WRONG. I have read post on SVT performance.com where many, many people have a ticking at idle from the heads. Plenty of guys had the heads done to try and fix it.

LT193

Well i know my buddies GT is stout at idle for exaust noise and for ticking. It is the smoothest quietest motor i have ever heard running. I wonder what would happen if u had a 5.7 modular vs an LS1 with the same compression. I really dont know how much more efficient the overhead cam thing is but i know when u start getting multiple valves it really is amazing how much power they get outta the cobra motor. Considering its a 281 with under 10-1 compression u know.