John Collins
Well-Known Member
I got the last pair of 6 leaf springs from ESPO. They hope to get more in the next month, but it could be much longer. About the same situation with Mancini Racing. I got super lucky.
LA 360 Engine refresh?
- Thread starter John Collins
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I got the last pair of 6 leaf springs from ESPO. They hope to get more in the next month, but it could be much longer. About the same situation with Mancini Racing. I got super lucky.
furrystump
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So I’m going the generic mechanical work route. I’m a bit of a control freak so I only really work alone. I have the wife help with the hood, but that’s it. For a novice I’m not sure getting the car high enough is wise, but it does eliminate hood removal. So my advice is attention to detail. If it feels wrong stop and ask on here. No such thing as a stupid question. No rushing and no time estimates. Two bolts can take 2 mins or 2 days it lowers the frustration level if you don’t set time estimates. Like “I should be able to drop it in by this afternoon” Also if there is even the slightest chance you could be building another motor. I would buy some cheap measuring tools. Nothing worse than you put it together and it doesn’t do what you want. When you ask for help people will ask questions you won’t know the answers to.
Dartswinger70
Well-Known Member
I did think about doing the same with my 86 Fox body. Pull the engine reseal everything. Its just a thought. i did everything "up top" intake valve covers etc. But still leaks down below. It has that rubber oil level sensor gasket ill try that next they are notorious for rear mains also (5.0 Fords)
John Collins
Well-Known Member
Thank you, I appreciate it! I’m in real rush, my only concern for timing was to work out a deal with my neighbor to ask him for a general amount of time that I can use his space. I’m torn about how to pull the engine, or whether to pull it at all and struggle with it in place. I like the idea of dropping it from below though with the K member attached, since I’ll be doing a front suspension rebuild as well. I gave a background in rigging and dealing with weighty pieces, but this is a first and I’m definitely gun shy. I have some time to think about it though as I wait for parts. Thank you again!
John Collins
Well-Known Member
I’ve been dealing with electrical issues that I thought were in the rear view and lost steam on this car and needed a break from “learning”/utter frustration. Lol. I did a compression test the other day and here are the numbers. This was dry and not at running temp. I still haven’t installed the 8 3/4 rear, or anything beyond rewiring/trouble shooting the engine bay.
1 155
3 158
5 160
7 159
2 166
4 160
6 155
8 154
1 155
3 158
5 160
7 159
2 166
4 160
6 155
8 154
Captainkirk
Old School Mopar Warrior
Compressions look fairly consistent. If it was me, I'd fix the leaks and drive it, and start socking away money for a crate motor. Trust me when I say you won't be on such good terms with your neighbor after a few weeks. You'll be under pressure to rush things, and despite your best intentions you'll have oil and antifreeze all over his floor. A pre-run crate will take far less time to drop in...when you're ready...and by then you may have your own garage to work out of. I'm building my 340 now (again) and the cost is likely gonna equal or exceed that of a crate motor by the time I'm done. I'm doing it in small chunks on my own time in my own garage, so that's OK. If I was in your situation I would be throttling WAY back on getting in too deep.
If you are really jonesing to get your hands dirty and get right in there with the alligators, I might suggest finding a good core motor and start building it to your specs. It will take up a whole lot less garage space than an entire car and you can put a drip pan under the engine stand. Just sayin'...
If you are really jonesing to get your hands dirty and get right in there with the alligators, I might suggest finding a good core motor and start building it to your specs. It will take up a whole lot less garage space than an entire car and you can put a drip pan under the engine stand. Just sayin'...
John Collins
Well-Known Member
Pretty spot on. I’ve switched gears and have been looking for a either a short block to start with, or an engine to brake down and rebuild. I want to learn more and this is a good opportunity. The short block will make it easy to start. I need to make a plan, but first I need to learn a whole lot more about building/rebuilding an engine. I’ve read a ton of threads and articles, but I still don’t know a thing about cams and how the math works. Lol. There’s a couple books that I’m going to buy. I want to find a simple combo that’s been tested and copy it, or take the other route of finding an engine and break it down, clean it up and prepped to go to the machine shop to get checked over and do what they recommend and clean then clean again and slowly reassemble with a combo of upgraded parts and refreshed existing parts. Whatever I do though, I need to formulate a plan and stick to it. Thank you for your reply!
Dartswinger70
Well-Known Member
Also think about what you want to do street or race etc. That will determine a direction. For me ,I am in the middle of a refresh of one of my 340s. I would like to be as close as I can get to a stock 68 340 4 speed engine. I am not sure the factory cam grind is available so I am open to suggestions on a cam, but I don't want anything too aggressive or that needs anything more than stock style valve springs. Point is to know what you want and how far to go.
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Captainkirk
Old School Mopar Warrior
What are your goals for it?
John Collins
Well-Known Member
Only street. Low miles daily driver. I just want something reliable, but fast enough to get the adrenaline going. The leak is what got me thinking about possibly building the engine up a bit... I think the engine I currently have is probably already enough though. With that said, I’m leaning towards a stock LA 360 short block with J heads with the 2.02/1.60 if I can find a pair that’s cheaper than Edlebrock Performer RPM heads, a Performer intake, 750 Holly DP carb and suitable cam(which I have no clue on).
John Collins
Well-Known Member
In a dream scenario, I’d start with a 340. I’ve been searching high and low and they’re way out of my price range. I might get lucky though.
Dartswinger70
Well-Known Member
yeah they are difficult because they only made them 5 years, and the good ones are the early ones so that leaves 3 years. It was the same in the early 90s when I found my car. It came with spare engines etc. I paid for the whole "basket case" car and parts back then what a "basket case" 340 costs now
Captainkirk
Old School Mopar Warrior
I have a "spare" '69 X-head 340 but I'm very reluctant to let it go. You don't find them on every street corner. Besides, I "stole" the forged crank out of it for my current '72 340 build. Figure if I ever build this one I'll go aftermarket forged.
The 360 can be built to perform equally.
The 360 can be built to perform equally.
Dartswinger70
Well-Known Member
Agreed. The only thing I dislike about 360 is the external balance. you need two distinct setups to swap fron internal to external balance. I have one 340 together and a 318 that will drop in and run,and I am in the process of getting another 340 together. I like the straight swap interchangeability between 318/340 with internal balance. Just to clarify not all 340s are internal balance I think the late 340s (72-73) are external balance also.
Captainkirk
Old School Mopar Warrior
They are. One of the reasons I'm using the forged crank this time around.
Captainkirk
Old School Mopar Warrior
He can get around that by using an aftermarket forged crank. Most, if not all of them, are internally balanced.
Dartswinger70
Well-Known Member
I did not know that. You learn something new all the time. I may go with a 360 one day if one comes along for the right price. I did have a 360 short block that I let go cheap back in the day. That was early 90s. Back then this stuff was dime a dozen except for 340. Everyone knew what they were. people dont realize that these engines perform well without much modification. They are V8 power, even a 318. You can build them up or run them stock, and they will run good. They make good make Small Block V8 power.
Captainkirk
Old School Mopar Warrior
Eagle LS Gen III, Big Block Chevy, Steel & Forged Crankshafts, Connecting rods & rotating assemblies
CHRYSLER SB FORGED 4340 STEEL CRANKSHAFTS
Forged SAE 4340 steel with non-twist forging and multi-stage heat-treatment
Micropolished journals feature a 3 r.a. or better
.125” radiuses improve strength and rigidity. Chamfered or narrowed bearings required.
Shot-peened, stress relieved, and nitrided for superior durability.
Target bobweight guaranteed +/- 2%. Designed for internal balance without heavy metal.
Recommended for use up to 1500 hp. Approximate weight is 57-60 pounds.
CHRYSLER SB FORGED 4340 STEEL CRANKSHAFTS
Forged SAE 4340 steel with non-twist forging and multi-stage heat-treatment
Micropolished journals feature a 3 r.a. or better
.125” radiuses improve strength and rigidity. Chamfered or narrowed bearings required.
Shot-peened, stress relieved, and nitrided for superior durability.
Target bobweight guaranteed +/- 2%. Designed for internal balance without heavy metal.
Recommended for use up to 1500 hp. Approximate weight is 57-60 pounds.
John Collins
Well-Known Member
I’d hold onto those X heads as well... They seem to be more rare than a 340 itself. I’ve seen really awesome builds with 360’s. Here’s a question. I currently have a performer 318/360 and Carter 625 carb. If I changed those out to a Performer RPM intake and a bigger flowing carb, will I need to modify anything else, such as degreeing the cam? Or will they be ok to just bolt on? These are two components I plan on using for the future build and an upgrade in my opinion to what I currently have. Also, mechanical vs electric choke carbs... What do you prefer and why?
yeah they are difficult because they only made them 5 years, and the good ones are the early ones so that leaves 3 years. It was the same in the early 90s when I found my car. It came with spare engines etc. I paid for the whole "basket case" car and parts back then what a "basket case" 340 costs now
What changed in ‘72 besides the heads? I know compression dropped considerably to 8:5-1 from the 10.3-1 in ‘71 and was only rated to 240 net HP. I’m guessing emission controls.
Awesome! This is another area that I need to research a lot more... External VS Internal balancing.
Captainkirk
Old School Mopar Warrior
Your intake choice will be heavily dependent on your choice of heads and valve size. @yellow rose and a few others did a really good thread about port shape and flow but I can't seem to find it now. Most street builds, especially milder ones, will benefit from a dual plane design, although the SP manifolds tend to get with the picture much better "upstairs". As you mention, in '72 the J heads changed over to 1.88 intakes, although these can be fitted with 2.02 intakes fairly easily. I've been told the X-heads flow better on the bench due to slightly different port shapes, but it's not likely you'll notice much on a street motor. Yes, compression dropped and the newer engines were outfitted with dish-top pistons, which did a bunch to de-rate the HP rating...however, IIRC there was something in the way HP was rated that changed in 1971 as well so it might be less of a drop than meets the eye.
Also, with the externally balanced crank and damper, the timing marks on the timing cover were shifted to the left (driver's side) from the right side, also water pump and radiator were different as a result. A flywheel from a forged crank will not bolt up to a cast crank, if you're running a manual trans.
You really only need to degree a cam if you are changing it, for the most part. Certainly swapping carbs and manifolds won't require it.
WRT carbs; everyone has their favorite. I prefer the Holley double pumpers because they are darn near idiot proof and lend very easily to tuning. My last build was really finicky on start up; needed plenty of choke, but after lighting off would run richer than hell unless it was wide open so a manual choke was the easiest and best solution. Fire it up and then open the choke. I suppose an electric choke would be fine if your motor likes it?
Also, with the externally balanced crank and damper, the timing marks on the timing cover were shifted to the left (driver's side) from the right side, also water pump and radiator were different as a result. A flywheel from a forged crank will not bolt up to a cast crank, if you're running a manual trans.
You really only need to degree a cam if you are changing it, for the most part. Certainly swapping carbs and manifolds won't require it.
WRT carbs; everyone has their favorite. I prefer the Holley double pumpers because they are darn near idiot proof and lend very easily to tuning. My last build was really finicky on start up; needed plenty of choke, but after lighting off would run richer than hell unless it was wide open so a manual choke was the easiest and best solution. Fire it up and then open the choke. I suppose an electric choke would be fine if your motor likes it?
Captainkirk
Old School Mopar Warrior
Oh, I have the rest of the motor to go with them! (except the crank that I swiped)
John Collins
Well-Known Member
I’m going to search for that thread. Thank you for all your input!!
That’s awesome!!
That’s awesome!!
Captainkirk
Old School Mopar Warrior
Dartswinger70
Well-Known Member
John Collins
Well-Known Member
I decided to slowly build an engine. I’m waiting on a shipping quote for a (Hasn’t been run since machined) bored .40 over LA360 from ‘75 with 974 heads and original crank. All in excellent condition, the block is ready to get a couple final cleanings and for the bottom end assembly. Hopefully the shipping doesn’t kill me and I go ahead with the purchase. This is the same combo I have in my car, other than my current block is a 4006830-360-9 and his a 360-2. It won’t let me download the pictures of the block for some reason. I’m going to start a build thread once I actually take possession of an engine... Hopefully it’s this one. I thought I had a line on a great deal for .40 over pistons, but it turned out to be around the actual retail cost and not a set I’d choose based on compression specs, but not a bad choice if my budget was shoe string(it’s not much more though. Lol). I would’ve started with a stock short block and been happy, but since this one will need pistons, I’m going to go a step up... Not by much, but a good step and money well spent, easily worth the extra $200 over the Sealed Power 405CP’s, which would’ve been an upgrade from stock compression at just under 9:1 with the .40 over, but I can get around 10:1 from Keith Black or Speed Pro, depending on which way I go on the build. I’m learning every day and looking forward to starting a build, now that I’ve decided on a direction. Thank you CaptsonKirk and the rest of you! Side note, randomness. I was was Shatners driver on a movie for a few days. I was driving the Electric 10ton tractor truck, but got pulled to drive him around for the few days he was shooting with us. He was hilarious and a stand up guy.
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