318 LA mildish bolt-on tuning?
318 LA mildish bolt-on tuning?
It looks like I will get the go-ahead on putting an LA engine into the 541. What is the best option for getting ca. 300hp (DIN) from a 318LA? I want the engine to look as standard as possible so no obvious external changes. I am prepared to make a discrete throttle body injection based on the original carb though. Will it be enough to fit a different cam + TB injection? Or do I need to look at a stroker kit as well? If I have to have a stroker kit, how do I pick a suitable cam?
Per
Not only English cars these days, an Italian is part of the stable again
Not only English cars these days, an Italian is part of the stable again
Re: 318 LA mildish bolt-on tuning?
Per,
Since all of the LA motors look virtually identical why not up the ante with a stroked 360? At 408cuin you can keep the build very mild and still make well over 300hp. I do like 318s, but their heads are not very good until the magnum 5.2l motor came out in 91. My 3200lb 72 Barracuda is a 318 powered car and makes 250hp a the rear wheels. it runs its original block, heads, crank and rods. Its a lot of fun to drive while not being a handful. I would have preferred a stroked 360, but the (cheap) parts for that build were not avail when I put it together in 89. If you must go with the 318, my recipe for 300+ hp is as follows:
Bigger intake valves. I put in 1.88 chevy valves. no block notching needed and minimal shrouding.
Port the heads by hand. clean up the bowl and guide area, port match it to a good intake
You wont like this, but you MUST ditch the stock 2bbl intake. Suggest anything from edelbrock.
Up the compression ratio to 9.8:1-10.25:1 I used Silvolight pistons... They are cheap, but they are also castings... Today Id go with a set of forged JE pistons.
Stock rods and forged stock crank work well for no addtl stroke. this crank for the 318 will get you about 360cuin... for over 1K USD... not a good deal http://www.summitracing.com/parts/dcc-5007253" onclick="window.open(this.href);return false;
Stick with a fairly mild cam with a 112LSA .484 lift works good on the stock heads. Much more and the bottom end torque will go away. Duration wise Id stay under 230 deg
I run a multiport multi throttle body intake controlled by a BIGSTUFF ECU with 24lb injectors.
Long tube hooker headers are on the Barracuda, not sure what you'll do for the 541, but the stock 318 cast iron manifolds are not good for performance.
Looking stock was never a consideration for the Barracuda as its an AAR tribute car.
Suggest the new Atomic TB injection system from MSD with a edelbrock intake manifold for discreet and inexpensive EFI.
Since all of the LA motors look virtually identical why not up the ante with a stroked 360? At 408cuin you can keep the build very mild and still make well over 300hp. I do like 318s, but their heads are not very good until the magnum 5.2l motor came out in 91. My 3200lb 72 Barracuda is a 318 powered car and makes 250hp a the rear wheels. it runs its original block, heads, crank and rods. Its a lot of fun to drive while not being a handful. I would have preferred a stroked 360, but the (cheap) parts for that build were not avail when I put it together in 89. If you must go with the 318, my recipe for 300+ hp is as follows:
Bigger intake valves. I put in 1.88 chevy valves. no block notching needed and minimal shrouding.
Port the heads by hand. clean up the bowl and guide area, port match it to a good intake
You wont like this, but you MUST ditch the stock 2bbl intake. Suggest anything from edelbrock.
Up the compression ratio to 9.8:1-10.25:1 I used Silvolight pistons... They are cheap, but they are also castings... Today Id go with a set of forged JE pistons.
Stock rods and forged stock crank work well for no addtl stroke. this crank for the 318 will get you about 360cuin... for over 1K USD... not a good deal http://www.summitracing.com/parts/dcc-5007253" onclick="window.open(this.href);return false;
Stick with a fairly mild cam with a 112LSA .484 lift works good on the stock heads. Much more and the bottom end torque will go away. Duration wise Id stay under 230 deg
I run a multiport multi throttle body intake controlled by a BIGSTUFF ECU with 24lb injectors.
Long tube hooker headers are on the Barracuda, not sure what you'll do for the 541, but the stock 318 cast iron manifolds are not good for performance.
Looking stock was never a consideration for the Barracuda as its an AAR tribute car.
Suggest the new Atomic TB injection system from MSD with a edelbrock intake manifold for discreet and inexpensive EFI.
Re: 318 LA mildish bolt-on tuning?
Thanks Bruce 
It will have to the 318. Only pistons then. I had picked a 0.454 cam with 216 deg so that seems fine. Edelbrock will have to be it with a single TB. The stock manifolds will have to go anyway as custom headers will be a necessity to clear the other basic hardware. I will need to hide the TB so butchering a suitable carb and putting injectors inside must be investigated. Alternatively one of your TBs and a butchered carb with the injectors on top? What size the TB, 2x50mm? And what injector type(s)? I was thinking of Megasquirt, as much for the fun of building it as any other reason. I'll use Pertronix in an original dizzy.
It will have to the 318. Only pistons then. I had picked a 0.454 cam with 216 deg so that seems fine. Edelbrock will have to be it with a single TB. The stock manifolds will have to go anyway as custom headers will be a necessity to clear the other basic hardware. I will need to hide the TB so butchering a suitable carb and putting injectors inside must be investigated. Alternatively one of your TBs and a butchered carb with the injectors on top? What size the TB, 2x50mm? And what injector type(s)? I was thinking of Megasquirt, as much for the fun of building it as any other reason. I'll use Pertronix in an original dizzy.Per
Not only English cars these days, an Italian is part of the stable again
Not only English cars these days, an Italian is part of the stable again
Re: 318 LA mildish bolt-on tuning?
Per,
Your cam choice is a wee bit mild for a full 300hp. Id go a bit bigger and definitely port the heads and install bigger intake valves. LSA is the lobe separation angle, duration is the amount of time the valve is open. 112 LSA is good for bottom end (not much overlap at lower durations), and duration of 222-230 is very mild (smooth idle). I think my suggestion of the MSD or FAST EZ 2.0 throttle body injection is still your best bet to get EFI performance without the hassle. You cant see it under an air cleaner. If you want easy HP start with a Magnum 5.2 motor instead of the LA. Looks virtually identical but makes a lot more hp the easy way. You can use the magnum heads on the LA motor, but youll need a magnum intake manifold and valve covers to match. A niggling problem with aftermarket LA 318 intake manifolds is that every 4bbl unit has 340/360 ports, even the factory cop car intakes. They will mismatch to the 318 head ports and will need to be filled (like my 6 pack intake). The easy way out is 340/360 style aluminum heads.
Heres a video link from COMP re: FAST EZ 2.0 installation: https://www.youtube.com/watch?v=MXiX3EBT9dE" onclick="window.open(this.href);return false;
Oh...Make sure to use a new vibration damper as any OEM unit is by now kaput.
Bruce
Your cam choice is a wee bit mild for a full 300hp. Id go a bit bigger and definitely port the heads and install bigger intake valves. LSA is the lobe separation angle, duration is the amount of time the valve is open. 112 LSA is good for bottom end (not much overlap at lower durations), and duration of 222-230 is very mild (smooth idle). I think my suggestion of the MSD or FAST EZ 2.0 throttle body injection is still your best bet to get EFI performance without the hassle. You cant see it under an air cleaner. If you want easy HP start with a Magnum 5.2 motor instead of the LA. Looks virtually identical but makes a lot more hp the easy way. You can use the magnum heads on the LA motor, but youll need a magnum intake manifold and valve covers to match. A niggling problem with aftermarket LA 318 intake manifolds is that every 4bbl unit has 340/360 ports, even the factory cop car intakes. They will mismatch to the 318 head ports and will need to be filled (like my 6 pack intake). The easy way out is 340/360 style aluminum heads.
Heres a video link from COMP re: FAST EZ 2.0 installation: https://www.youtube.com/watch?v=MXiX3EBT9dE" onclick="window.open(this.href);return false;
Oh...Make sure to use a new vibration damper as any OEM unit is by now kaput.
Bruce
Re: 318 LA mildish bolt-on tuning?
Would Edelbrock heads+intake+cam bring me there, or close? I haven't opened the engine I have yet but it is supposed to be OK apart from a burnt valve, so keeping my options open. BTW the main reason for going to TB is that I am comfortable doin g tuning via a laptop but less so fumbling with carb jetting, and of course driveability.
Per
Not only English cars these days, an Italian is part of the stable again
Not only English cars these days, an Italian is part of the stable again
Re: 318 LA mildish bolt-on tuning?
Per,
Yes the Edelbrock combo works well and should get you to where you'd like to be HP wise. You can use the FAST Sportsman system with their EZ 2.0 throttle body for full laptop tuneability at about the same price as the self tuning set-up (and IMO its a better way to go). The MS3.0 pro is a good system and is very flexible. Youll still need to come up with a TBI style throttle body. MS should be able to drive an older Holley TBI unit, but that's kind of primitive...
Bruce
Yes the Edelbrock combo works well and should get you to where you'd like to be HP wise. You can use the FAST Sportsman system with their EZ 2.0 throttle body for full laptop tuneability at about the same price as the self tuning set-up (and IMO its a better way to go). The MS3.0 pro is a good system and is very flexible. Youll still need to come up with a TBI style throttle body. MS should be able to drive an older Holley TBI unit, but that's kind of primitive...
Bruce
Re: 318 LA mildish bolt-on tuning?
I have looked into the built up Speedmaster heads with matching intake manifold. With e.g. 2.202 intake valves they look like a good idea, particularly at the price they charge? Is the cam as you have described above still right for those heads? (Fetching the engine this coming weekend and will start dismantling immediately.)
Per
Not only English cars these days, an Italian is part of the stable again
Not only English cars these days, an Italian is part of the stable again
Re: 318 LA mildish bolt-on tuning?
Per,
A friend purchased a set of the Speedmaster heads for his 440. Castings were OK, valves, springs and valve job were junk... I cant recommend them...
Bruce
A friend purchased a set of the Speedmaster heads for his 440. Castings were OK, valves, springs and valve job were junk... I cant recommend them...
Bruce