[RCCADMAN]

Stroker kit maybe? 360 to a 408 or so?

 

[Canadian country boy]

Jesus guys, I wasn't expecting all of this information. I asked for it though, so thanks.

I'm still a total beginner with working on stuff and especially with engines, so this is kind of a lot. As such, let me try to narrow things down a bit. I don't have the tools (or knowledge, for that matter) to do a motor swap, so for now I'm going to rule out a magnum or a big block. They would be nice, but for my purposes I think it'll be far more manageable for me to just modify the engine I already have. To bring everyone up to speed if they haven't read the whole thread, this motor is an early 90s (not sure on the exact year so let's call it a 90) 360, has an Edelbrock 1406 600cfm 4 barrel carb, LD340 intake, headers, and dual exhaust. Everything else is stock. So, the question now is where to go from here. I'm a little confused on compression because the comments are conflicting. Some of you are saying stock is fine, some are saying to go higher. So which is it? And how do you go about increasing compression?

For the record, I most likely won't be tearing into this until next year sometime, so I've got time to think about it. I just wanted to start asking around to get some ideas.

Again, the answer to your question is: what do you want out of your engine - power or economy or reliability and durability? If you're kinda happy with what you have but just want a little more power and economy then just focus on some add on's like a good ignition system and some roller tip rockers and a bigger carb (for power) and a good tune job or if you want more power then you rip your engine out and tear it apart and have it bored for bigger pistons and a higher compression ratio, deck the block and buy a good set of aftermarket heads. The combinations and possibilities are almost endless. Just decide what you want.

 

[jerseybud]

the good- you have the 308 heads. Think of them as pre-magnum. were swirl port. Pretty good for a street motor. would need 1.92 or 2.02 valves for 300 plus hp.

the bad- low compression truck engine and tiny cam. Not just any cam but a roller cam! Less friction, less aftermarket availability. And you deserve the urine of a thousand cats on your bed if you switch to a flat tappet cam with todays metallurgy and oils.

Heres what I would do- jet the carb, fine tune everything. read the edelbrock manual for that carb (on website) be an expert on it. They are finicky critters and I found my 1406 needed 2 tunes- summer and winter. Keep the fuel cool, use a big ass carb insulator. Optimize the igntion. Keep tranny adjusted- learn to be an expert on that. Read the FSM for the 727/518- do the bands. be sure the kickdown is right.
You might get back to the factory rating of 190 hp (engine!). Just not a much you can do without getting into engine.

 

[TheBohunk]

Yeah if you don’t have the ability to do an engine swap, then doing an actual build is going to be tough.

I would do the above mentioned with your ignition, carb, rockers and such. I might also add a better cam. But keep In mind you are going to be limited with what you can achieve with your current bottom end. This is what I was getting at when I said 350 out of your current motor is very optimistic with your current pistons.

Different pistons is pretty much the only meaningful way to bump up compression. You can deck heads and a few other things to make some small gains but new pistons is the big one

Some minor porting in factory heads can wake up a stock motor too. But that’s tricky and you can ruin a head if you don’t know what you are doing.

 

[NitroMachine]

Yeah if you don’t have the ability to do an engine swap, then doing an actual build is going to be tough.

I would do the above mentioned with your ignition, carb, rockers and such. I might also add a better cam. But keep In mind you are going to be limited with what you can achieve with your current bottom end. This is what I was getting at when I said 350 out of your current motor is very optimistic with your current pistons.

Different pistons is pretty much the only meaningful way to bump up compression. You can deck heads and a few other things to make some small gains but new pistons is the big one

Some minor porting in factory heads can wake up a stock motor too. But that’s tricky and you can ruin a head if you don’t know what you are doing.

So what pistons/heads/cam do you think would work best for this motor? I want to figure out the combination of parts I do/don't want so I can start looking at prices and figure out how much I'm willing to spend.

 

[TheBohunk]

So what pistons/heads/cam do you think would work best for this motor? I want to figure out the combination of parts I do/don't want so I can start looking at prices and figure out how much I'm willing to spend.

I’m probably not the best guy to ask. I’ve never done a 360 and It’s been 15 years since I did a full build, I’m kind of out of the loop.

Some of the other guys here probably have some good recipes.

You might want to pick up the old mopar small block book and do some reading. It’s probably out of date by now but it will get you some ideas

Small Block 'A' Engines (Mopar Performance Parts): Mopar Performance Parts: Books: Amazon.com

Small Block 'A' Engines (Mopar Performance Parts) [Mopar Performance Parts] on Amazon.com. *FREE* shipping on qualifying offers. Small Block 'A' Engines (Mopar Performance Parts)

www.amazon.com

 

[Canadian country boy]

I would find a '97 or '98 (I forget which year it is) and later Magnum and hop it up a bit like I did. It's a better engine for sure and starting off with better power. Your engine has decent heads on it now but if you're looking for more then you'll need decide if you want aluminum heads or steel heads because that choice determines how much compression you will need. Aluminum doesn't hold as much heat as steel heads do so you can bump the squish up a bit over steel. I don't know what your octane rating is in your area but in my parts, the best gas I can buy is 94 octane out of the pump and therefore can not go more than 9.5:1 (approx) with steel or around 10.25:1 (approx) with aluminum if you want to protect your new engine from detonation damage, and then of course choose a cam for the RPM's you plan to do. You already have a good intake, get good a set of roller rockers and a Pertronix ignition system and your out digging trenches!

 

[NitroMachine]

I would find a '97 or '98 (I forget which year it is) and later Magnum and hop it up a bit like I did. It's a better engine for sure and starting off with better power. Your engine has decent heads on it now but if you're looking for more then you'll need decide if you want aluminum heads or steel heads because that choice determines how much compression you will need. Aluminum doesn't hold as much heat as steel heads do so you can bump the squish up a bit over steel. I don't know what your octane rating is in your area but in my parts, the best gas I can buy is 94 octane out of the pump and therefore can not go more than 9.5:1 (approx) with steel or around 10.25:1 (approx) with aluminum if you want to protect your new engine from detonation damage, and then of course choose a cam for the RPM's you plan to do. You already have a good intake, get good a set of roller rockers and a Pertronix ignition system and your out digging trenches!

A lot of stuff is interchangeable between the LA and magnum series isn't it? I know not all, but I've read about guys putting magnum heads on an LA block. Don't know if that's be worth it really though.

 

[NitroMachine]

Also, full size pickups, dakotas, and durangos of those years all have the magnums don't they?

 

[Canadian country boy]

Yes, you can swap parts but it gets tricky. The Magnum blocks (especially the '98 and later) has better compression pistons than your 360 does stock so if you want to keep costs down just look for a low mileage Magnum and start there. Yes, the Magnum's are found in those vehicles.

 

[1970Pelle]

I just had a 318 come back from the machine shop. Here is the list of work done and new parts. Bored 0.030 with 8 new pistons, which are 10:1. New camshaft bearings, freeze plugs, block cleaned up and all clearances checked.
Cylinder heads cleaned, new seats and guides, 8 new intake valves 1.88, my 1.6 exhaust valves worked alright. A three angle valve grind was done, back cut the valves, along with porting the pockets and intake ports and exhaust ports before going into the machine shop.
The crankshaft had to be cut to 10/10 on the Mains and Rod bearing journals.
So with eight new pistons & rings, rod & main bearing sets. Full engine rebuild gasket set, timing chain & gears(double roller) high volume oil pump. Freeze plugs, camshaft bearings, eight intake valves, 16 valves and 24 valve guides.
I have to double check everything. I'm currently weighing everything, so I'm as close to balanced as possible. Deburring the inside and outside of the block and heads(I had most of this done before hand). And starting the engine assembly, I'm not in a real big hurry, so I have time to mess around with stuff. I have a new degree wheel coming in, I have the extra bucks for one of the big degree wheels.
So all this with parts and labor from the machine shop came to. $1700.00

And I had all my parts clean when they arrived there, there was little work needed on the outside of my stuff. I had let the parts drain for days, before tearing anything apart. Also cleaned all gasket surfaces. There job was some what a bit easier.
Have you noticed how much or the large amount of rough metal, edges hard lines. On a Mopar engine form the 1960 and 70's. I asked this question several times up north and never was given a good answer. If it was a mold issue or a chipper problem.(chipper) guys cleaning the castings out of the molds. So I take the time and clean my stuff up. Do others also clean there's up?

Ken

 

[Canadian country boy]

Hey Ken, welcome to RCC. Yes, deburring your block, heads and engine parts are always a good idea if you have the ability but it's not as critical for a mild street engine. Factory assembled engines can last a long time with no major issues. It's not until you start making some real power where it becomes beneficial but if you have the time and know what and where to debur, then have at it.

 

[Canadian country boy]

This title is misleading when it says "junkyard" when it is not entirely stock and has been rebuilt with a lot of good performance parts but look at the power numbers for a 360LA......

 

[Canadian country boy]

And here is a mostly stock LA360 making just over 300 horsepower, so 350 horsepower would be possible on a stock 360 with a more aggressive cam, better springs a set of roller rockers, and porting.

 

[Canadian country boy]

And here's one more. This guy lives in my town and dyno's his stuff at my friend Peter's house who has an engine dyno at his house. This engine has a 10.0:1 360 in it that makes over 400 hp. Of course this engine is more for a street car and not a 4x4 but my point is if power is what you want then this is an example of what kind of numbers you can achieve on a mild build 360.

 

[1970Pelle]

Thank you Canadian Country Boy, I have reviewed the Hot Rod article and Video on YouTube. Along with quite a few others. I have been around Mopar's since I was 15. And as my career for 28 years as a dealership tech. I also had the chance to work at the Conner Ave Plant for a period of time before it closed. I had a spot in R&D on the Prowler line. A story for another thread.
So building engines is very natural for me. This current build should yield some good HP numbers. With the compression ratio, the choice in camshaft= Comp Cams 20-220-3 with Comp valve springs and valve hardware, lifters. Edlebrock performer intake manifold (dual plane) with suggested mods. I have changed my mind on Carbs, I like the Edelbrocks and the Quick Fuel carbs work very good also. So if I can get a better deal on the quick fuel that's what I'll run. An HEI ignition, and all the head work, the engine should run pretty decent. I'm not expecting a wheel standing power house. I also built a transmission to match the engine.
So we'll see in a short while. I'm also dealing with a small bit of body work, at the same time. Both my doors have broken(cracked) around the lower door hinge. Which has doomed the doors out, I have located really nice used replacements. I'm going to change the front fenders also run your hand down the top of each fender. Its a bumpy ride, most likely someone laid across the fenders working under the hood and didn't watch how much weight they put on the tops of the fenders. Trashed them both, I could use a thin layer of body filler to fix the issue. I hate body filler, period.

K

 

[NitroMachine]

And here is a mostly stock LA360 making just over 300 horsepower, so 350 horsepower would be possible on a stock 360 with a more aggressive cam, better springs a set of roller rockers, and porting.

Yeah I watched this one, which is why I was a little confused when guys were saying you have to tear into the bottom end to break 300.

 

[Canadian country boy]

300 horsepower is a conspiracy NitroMachine, didn't you know that? Lol.
Engines are not very well understood by many people. I myself have been building engines since 1986 and have won many races and a couple of championships at our race track. I also built my engine in my '88 Trans Am that won the 1996 Car Craft Magazine Real Street Eliminator competition in California. I drove my car all the way to Cali (1100 miles) and kicked everybody's ass and then drove 1100 miles all the way home! 😎
Anyways, engines are my thing.

 

[NitroMachine]

300 horsepower is a conspiracy NitroMachine, didn't you know that? Lol

I do know this thread is making me wish I had a 70s motor instead of an early 90s, I think it would've made this a little bit simpler.

 

[Canadian country boy]

Thank you Canadian Country Boy, I have reviewed the Hot Rod article and Video on YouTube. Along with quite a few others. I have been around Mopar's since I was 15. And as my career for 28 years as a dealership tech. I also had the chance to work at the Conner Ave Plant for a period of time before it closed. I had a spot in R&D on the Prowler line. A story for another thread.
So building engines is very natural for me. This current build should yield some good HP numbers. With the compression ratio, the choice in camshaft= Comp Cams 20-220-3 with Comp valve springs and valve hardware, lifters. Edlebrock performer intake manifold (dual plane) with suggested mods. I have changed my mind on Carbs, I like the Edelbrocks and the Quick Fuel carbs work very good also. So if I can get a better deal on the quick fuel that's what I'll run. An HEI ignition, and all the head work, the engine should run pretty decent. I'm not expecting a wheel standing power house. I also built a transmission to match the engine.
So we'll see in a short while. I'm also dealing with a small bit of body work, at the same time. Both my doors have broken(cracked) around the lower door hinge. Which has doomed the doors out, I have located really nice used replacements. I'm going to change the front fenders also run your hand down the top of each fender. Its a bumpy ride, most likely someone laid across the fenders working under the hood and didn't watch how much weight they put on the tops of the fenders. Trashed them both, I could use a thin layer of body filler to fix the issue. I hate body filler, period.

K

That sounds like its going to make some decent power 1970Pelle. Can't wait to hear how it turns out!
I also have experience with bodywork from always having to repair damage from oval track racing plus when I had my race shop I started getting into rebuilding damaged vehicles from the insurance company for some extra cash. If I were you I would hammer and dolly the dents out on the fender and then just use a light skim of body filler to smooth it all out. Filler is perfectly fine as long as you keep it thin.