EFI SBC vs LS Motor

[Ron Sutton]

Originally Posted by redefined

Ron, my current SBC motor/tranny build is in the first post. I believe the compression is around 10:1 so not sure it'd do very well boosted. I did not build the motor myself but that's what I was told. That and I don't really have anything against carbs, I just want the reliability and consistency that seems to come with fuel injection. This is the first car/motor I've ever owned that's carbed. I need to start with having it tuned correctly, both the carb and the motor.
* Yes.


Have I decided LS or SBC? I'd really like to do LS, but again I have nothing against SBC. Have I decided 100% fuel injection? I suppose the answer is no. I have a friend that runs a carbed LS motor in his Panoz race car and that seems to run like a scolded monkey and cranks after 2 pumps of the gas EVERY time, mine doesn't even do that.
*Because this ...

Like I said previously also, 700hp isn't a must have. I'm not chasing a whp, a 1/4 time or anything like that. Someone had ask me a goal so that's what I threw out. More of a goal is reliability for the street, road course, autocross, than power numbers. I'd rather have 550whp and have it turn over 100% of the time I turn the key. I'd also rather not smell like exhaust/fuel every time I drive it haha!
* and this ...

are tuning issues.

All of my race engines fire easily after 2 pumps of the throttle.

[redefined]

Well that's all great news. Sounds like that will be the best way for me to go then!

I'll see if I can find a good tuner/builder local. Happen to know anyone in the Atlanta area?

[WSSix]

Originally Posted by redefined

Right but what kinda power with 5-6psi? At that level of boost is it really worth it? Not worried about the cam, if it's not good I don't mind swapping out cams but is it good for it? Probably not but not sure.

Also what would the best way to simply change the compression on my motor? BMW guys use different headgaskets, granted the headgasket is a weak spot in those motors but they use them to lower the compression on a stock motor. HG, pistons? And change cam?

Pro-charger kits on LT and LS engines add 100-150 hp with 5-6 psi. You'll need to investigate your engine first to know what power you're making now and what exactly you have. I use the LT and LS engines as examples since they are high compression v8 street motors like your motor.

You can easily change cylinder heads to drop compression. You may even pick up a better cylinder head that will make more power. The beauty of a SBC is the ridiculous amount of parts out there for them. You have so many options that it can be over whelming at times.

Changing cams can also help control your static compression. You'd want to work with an engine builder that really knows boosted engines to make sure it's selected correctly.

If you do go the Pro-Charged SBC route, I'd recommend you work with a engine builder anyway to select a cam. That way you get the most out of the combination. I'd hate to see you go this route only to be underwhelmed. I love seeing different approaches. That's a huge part of why I like this scene.

[redefined]

Yeah a good tuner friend of mine recommended http://www.nickersonperformance.com/ so I sent them an email. My friend doesn't do carbed motors and that's who he sends everyone to who needs that service. They do tunes and build carbs and make cams as well. So we'll see what he says!

I'd be great to still get some nice power out of this motor, even if I have to change a few parts around!

[Sparks67]

Originally Posted by WSSix

You'd want to work with an engine builder that really knows boosted engines to make sure it's selected correctly.

If you do go the Pro-Charged SBC route, I'd recommend you work with a engine builder anyway to select a cam. That way you get the most out of the combination. I'd hate to see you go this route only to be underwhelmed. I love seeing different approaches. That's a huge part of why I like this scene.

All engine builders won't bother with a used motor. They want to build you a new one. There is no money in it for them. Also realize that all engine builders are busy building next season's engine in the winter months.

If the OP ultimate goal is 600 to 700RWHP in an LS engine, then that is your best option. I owned several SBC in the past,and I looked into several different blowers for my fresh 383 (612hp/520ft/lb) engine option in the past. SBC is a waste of time for blower engine as compared to an LS engine. I decided to go with an LS418 with a Harrop TVS 2300. (building a blower engine is built from the block up, and it is rather expensive.) (Custom built engine) Actually, I had the LS418 for sale in the past, because we was talking about going for a little more power. Although, it was about impossible to sell the engine in the forums.

Personally, I would recommend that OP just start working on the front and rear suspension, new rear end, new wheels, brakes, etc. Use the current engine for now, but any local speed/engine shop would be able to adjust your carb. Building a first gen with a blower is rather expensive, so be sure you have the cash to do it.

Jeff

[Sparks67]

Originally Posted by redefined

Yeah a good tuner friend of mine recommended http://www.nickersonperformance.com/ so I sent them an email. My friend doesn't do carbed motors and that's who he sends everyone to who needs that service. They do tunes and build carbs and make cams as well. So we'll see what he says!

Almost all engine builders don't reply to emails, so it is best to contact them by phone or do a shop visit.

Jeff

[redefined]

Originally Posted by Sparks67

Almost all engine builders don't reply to emails, so it is best to contact them by phone or do a shop visit.

Jeff

Not local to me. And this is how I was told to contact him from a tuner friend who has used him multiple times.

Thanks for the info though.

I'm just at the point I need to decide to do what I can NOW or build what I really want. Which might require building the motor and running it NA for a little till I build the turbo or s/c setup.

[Windsor GTO]

Bill Mitchell has a conversion that allows LS top end on SBC bottom end. Gets you the best of both worlds....worth looking into at least.

[Vegas69]

Bill Mitchell doesn't have the best reputation.

[makoshark]

I went through this debate when I built my SBC. It ultimately came down, for me, to budget and already having a large amount of the SBC stuff sitting around.

If I were at that juncture right now, I would seriously consider an LS over the SBC, but there again it would come down to budget. However, to me, I wouldn't consider the 4.8/5.3 or the LS1. I have an LS1 now and didn't ever really consider using it. Those early LS motors are antiquated compared to the new LS3 setups. The LS3 has even nearly knocked out the LS2 out of the equation. I look at the LS setups now as having the ability to unshroud the valves. LS motors main benefit is the head design. The LS3 has the ability to run the LS7 style head and not constrict air flow into the cylinder. That gives you the ability to run the 11* heads with a large bore. All this takes out the early LS series motors out of the contention, to me.

With all that said, after tallying the final cost I have in my SBC, I could have easily purchased an LS3 crate or even built one for what I have in my SBC. I did, however, have a lot of SBC parts already purchased and sitting on my shelf that I did factor into the final cost of my motor build.