I appreciate everyone's time and thoughts regarding this topic. I'm diving in to my first "real" car project with equipment and ideas that I have no experience with.

My project is building a kit car that will use an LS1/T56 drive train.

After owning a Dodge SRT-4 I am VERY wary about engine mods of any type. I won't even go into that nightmare of a car. That being said, it is my understanding that there is probably no more worthy engine to work on than the LS1.

My plan for the drivetrain is to purchase an LS1/T56 dropout from one of our members once the kit is ready to receive the drivetrain. The kit will be driven on the streets and occasionally driven on a track.

Now, I don't need gobs of horsepower due to the low weight of the kit. I wanted to keep the engine close to stock but make smart improvements. Here is what I have come up with for "modifications" on an LS1 engine:

Accusump oil sustem
Oil cooler
Katech oil pump
Batwing oil pan

Perhaps a blueprint of the engine...It seems like if I'm going to invest in something like this I can spend the change to have this done. Am I nutty for thinking about that on a stock LS1?

ARP bottom end fasteners

Long tube headers made for dual side pipe applications

The air intake is in an open engine bay. I'm not sure where to go with something like this.



Eventually I'd like to look at the cam and the head but only for very mild HP increases. I'd rather go with something that will suit street running. It should also be noted that I'll be using a respected tuner in my area to assist with the first startup and tuning of the engine (and vehicle as a whole). I'm thinking in my situation that a good tune will be the best performance "modification". I also skip talk about the transmission since I have NO idea what will truly help.

My mindset with these thoughts is to get a "stock block" that is very reliable and puts out good solid performance. I'd rather have peace of mind than a few seconds of adrenaline only to be let down the first time I track the engine. I don't need much from a 1460 lb vehicle (w/the drivetrain included in that weight). Efficiency is the key to everything as I see it.

Again, your input on this is more than welcome.



Thoughts?

 

Is this vehicle going to be raced or pushed hard? Some known weak spots in these engines are oil pumps, pushrods prone to bending under high revs, and stock valve springs that float at high rpms. So those 3 would be on my list to replace even on a healthy engine. If you don't plan to live above 6500 rpms, I wouldn't do much else to it internally at the moment.

 

I agree with the above. A cam I like is the ASA cam. It can be used with ls6 springs, but 918's will last a lot longer. The cam has a heavy chop but drives very well and is easy to tune. It's not a power house, but will put down more than enough for a light cruiser/occasional track outings.

 

Yeah it will be tracked, but not more than probably twice a year. Even at that, it would be for my enjoyment and not in a race series. I'm hoping to pay one of my acquaintances to teach me how to drive a high performance machine on a track and on the street. She's definitely qualified seeing as she's a lead instructor at the miller performance driving school and a speed world GT driver...

Most of the operation will be out on the street.

after looking around I'm seeing that the oil pump and the overall performance of the wet sump set up of the engine is something that needed to be looked at and that's why I put those those "modifications" in my original list.

the power to weight ratio of this kit is so much that I would almost be insane to put more than 500-550 hp to it and even be serious about keeping the back end controlled under heavy acceleration. Thankfully I have experience with composites and can make my own body pieces or modifications to the kit's body pieces to try to fiddle with aerodynamics and downforce.

Ultimately it's the idea of having the most reliable yet sturdy engine and transmission combination that I can put in a chassis like this. My biggest concern will be the tweaking in tuning of the suspension to get all that power to the ground effectively. I'll take a look at those pushrods and what were they, lifter springs? I would imagine I can have those replaced when the blueprinting of the engine happened.

Thank you both for your thoughts on this, it means a lot.

 

Add another thought.....you touched on it. The oil pan. Most complain about the sump pickup in an f-body pan. I am not up to snuff on the batwing pan, and it may be better. I know Improved Racing makes different baffle systems for use in f body pans to improve pickup during extreme situations. Next time I have my pan off I will be ordering one. Rumor is oil psi goes to 0 during hard launches at the drag strip. That's no good.

 

Oh absolutely! The thought that an engine isn't getting lubed correctly scares the hell out of me. I've had an oil pump go out on me before in the middle of traffic going uphill and boy that was not a good 30 seconds of noisy death to that little engine!

 

2 questions first:

what is the purpose of this car?
what year engine are we dealing with?

my suggestions:

quality air induction
long tube headers

if the car isn't really going to be pushed HARD, a lot - there is no reason to alter anything. i have ran my car to the rev limiter (6199) on the factory parts spanning 80k miles and 6 years. nothing in the engine has been touched. the car has 109k miles on it now and i'm not afraid to do anything with it in that regard. the engines are very tough. the oiling systems work well, sometimes too well in the respect that aftermarket pumps will quickly empty a stock capacity pan.

leave the internals alone. i'm highly doubting you will reach any of the limits regarding durability if you aren't pushing the car. i can't believe some of the **** i've done to my car and it hasn't blown up - yet.

define "hard launches"...? my car went high 1.5/low 1.6 for 2 years and never had an oil pressure issue. i doubt this kit car will be doing that.

 

oops.

 

The car will be for road track type performance. Most of the operation will be done on he public roads though.

I'll be paying attention to the suspension and handling quite a bit.

I'm looking to have around 4 1/2 - 4 lbs per HP... Yet not make the chassis uncontrollable. I've heard that can happen when this type of roadster gets over 500 HP. My goal is to keep it around 350 - 400 HP.

All that power isn't going to do me any good if I can't keep that back under control.

The recommendation is an LS1. Really and LS motor can be out in the car but the builder said they were having difficulties with mills cranking over 550 HP. The LS1 seems to be inexpensive enough to be realistic for a working man and able to be worked pretty easily.

 

1.5x and lower 60 ft range from what I've seen. I've seen dash videos of the needle dropping. It absolutely does happen. Of course, most aren't staring at gauges when taking off like that as there is a million other things to pay attention to.