360 build.

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Wyrmrider said:
motorhome could have had an easy or a hard life depending on loads and hills
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Well thats true I suppose. Its been here in the UK for most of its life. Im not sure if that means its had a hard or easy life but generally we dont have vast ranges of Hills it would have gone up. The Roads are so small and winding here that it would generally been confined to the Motorways.

Wyrmrider said:
did you do a compression check or leak down before taking the heads off? if not do it
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Good point! I'll do that as Ive not touched the Engine yet.

Wyrmrider said:
If bores look good you can either leave well enough alone or do a minimum hone and new rings
new pistons without a bore job has been done to get the compression up
use the KB quench dome pistons especially made for LA open chamber heads
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Ok cool, a minimal hone an be done at home? Good to know I could replace the Pistions easily if the Bores are good. :) I tried looking on Summit for Pistons but never seen anything like what you're describing.

Wyrmrider said:
if it has the premium engine with premium valves and real exhaust seats they are hard to find check the engine codes carefully
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Interesting, Ive never heard of a Premium 360 or would know what to look for?

Wyrmrider said:
check out the voodoo Lunati line but get your compression nailed down first
at least use the .028 Mr Gasket head gaskets- but you will still have no quench and have less compression than you think you do without measuring
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How do I get the compression down? Reduce it or measure it?

Ok, if I get a .028" Gasket set should I still shave the heads?

Thanks for the reply. :)
 
Use the .028 gasket with the heads shaved .060. Make sure you shave the intake side .057. Should put you close to 9 to 1 comp. HP mopar did a build years ago called budget 360. It was 9 to 1 engine, ported smog heads with 1.88 1.6 valves, summit racing 218in. 228ex. at .050 .441 lift on both and 114 lsa. rpm intake and 750 holley. Put it in a 73 challenger with 1 5/8 headers 3500 stall and 3.55s. Car ran 12.60s in the 1/4 mile. Very impressive and very cheap. I think they figured about 340 HP.
 
aaronk785 said:
Use the .028 gasket with the heads shaved .060. Make sure you shave the intake side .057. Should put you close to 9 to 1 comp. HP mopar did a build years ago called budget 360. It was 9 to 1 engine, ported smog heads with 1.88 1.6 valves, summit racing 218in. 228ex. at .050 .441 lift on both and 114 lsa. rpm intake and 750 holley. Put it in a 73 challenger with 1 5/8 headers 3500 stall and 3.55s. Car ran 12.60s in the 1/4 mile. Very impressive and very cheap. I think they figured about 340 HP.
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Awesome! I like those figures. :D

I read somewhere else on here that you can shave .060" off the Heads and nothing off the intake faces and not have any sealing issues, but I think that was with a .040" Gasket. Works on my 340 as thats what I have on there. But think I might be pushing it with a .028" Gasket. But while they are in the shop getting the .060" off I might as well.
 
Yes I've done .040 with the .028 gasket and it worked but had to oblong the intake bolt holes. Once torqued down port alignment was fine. I just hate to tell people this and it not work for them because of block tolerances.
 
Yes, it's always advisable to mill the intake faces after taking any more than .020, as there are too many tolerance stack up issues that start to negatively affect port and flange alignment past this point. On a whim, I was going to throw out a hand grenade guess (accurate to within 20%) earlier of 345 hp @ 5100 and about 410 lb feet at 3800 rpm. That's close enough to the magazine article results for me to say it here. I don't put a whole lot into what a dyno says though, as real world E.T. will show what a dyno can't. That should be pretty close with the mildly ported 587s with the chambers opened up for the 202 valves, along with the cam and induction from your 340. It's also assuming you got about a 9.2:1 compression ratio with all cylinder pressures within 10% of one another. I think your probably going to have dished pistons below deck, so even with the heads milled .060, .040 is going to be too thick to target that much compression. Which rear axle does it have? I am assuming 8-1/4. For your English countryside roads and four speed, you should really consider stepping up to 3.55 gears in this combination. It would make for a snappy driver with that 360 in that relatively light car.
 
trigger_andy said:
Ok so maybe get a new Cam instead of risking using an old 340 one?

Any particular one spring to mind?
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Are you sure there 2.92 gears?
What size tire?
What’s the goal?
Spirited driver?

Wyrmrider said:
or do a minimum hone and new rings
new pistons without a bore job has been done to get the compression up
use the KB quench dome pistons especially made for LA open chamber heads
Click to expand...
The KB-107 @ zero deck and a .040 gasket will come in at (or right close to a) 9.8-1 ratio. A small cam can cause detonation issues. A thicker head gasket may have to be employed or skip the block decking to zero.

A dome piston will make matters worse.


some like the stock 340 cam which is even longer and lower lift- what's with that?- long life for warranty early years and emissions later years
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There is no way you can call the 340 cam an emissions cam. Stop it already. Really! Just stop telling lies. Stop whining about what was and the reasons behind it. It was what it was and that’s it.
The engine still produced reasonable power with excellent drivability.
 
Right on! Let us know what you get on your compression test and decide from there, if your going to build the 340 in the future anyway, I would avoid the piston and ring job. If all you get out of it is 8.8-9.2 to 1 with the milling and the thin gaskets, it will still be a great street combination with the other mods.
 
Garrett Ellison said:
Yes, it's always advisable to mill the intake faces after taking any more than .020, as there are too many tolerance stack up issues that start to negatively affect port and flange alignment past this point. On a whim, I was going to throw out a hand grenade guess (accurate to within 20%) earlier of 345 hp @ 5100 and about 410 lb feet at 3800 rpm. That's close enough to the magazine article results for me to say it here. I don't put a whole lot into what a dyno says though, as real world E.T. will show what a dyno can't. That should be pretty close with the mildly ported 587s with the chambers opened up for the 202 valves, along with the cam and induction from your 340. It's also assuming you got about a 9.2:1 compression ratio with all cylinder pressures within 10% of one another. I think your probably going to have dished pistons below deck, so even with the heads milled .060, .040 is going to be too thick to target that much compression. Which rear axle does it have? I am assuming 8-1/4. For your English countryside roads and four speed, you should really consider stepping up to 3.55 gears in this combination. It would make for a snappy driver with that 360 in that relatively light car.
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Thanks for the reply. :) Anything over 300hp will be nice. Ok, I'll mill the Heads .060", get a set of .028" Gaskets and Mill the Intake side .057" as you suggest. :)

As I have an Aussie Charger they use a Borg Warner Open Diff with a 2:92 ratio. The next size up over there is 3:23 but obviously I want a Sure Grip, or LSD as they are generally called in Oz, even on Mopars. 3:55 is available too so maybe I should get that? But Ive been told that 3:23 with my open ratio 4 Speed will work best.
 
3.23’s are fine if the tire stays stock size and it can use a small cam just fine. I would t to much larger than the stock size 340 cam.
 
rumblefish360 said:
Are you sure there 2.92 gears?
What size tire?
What’s the goal?
Spirited driver?
Click to expand...

Yes, almost 100%. I just asked again on the Aussie FB page to confirm and unless my Chargers been optioned thats what it will have. Is that an unusual ratio in the US?
Im not home to look at tyre size, 15" anyway.
The goal is to put under $1000 into this engine in as short a time frame as I can, get it installed before the summer and the new baby comes along. :O A goal I do have in mind is lots of fun and also when the 340 is rebuilt have a nice motor to sell to off-set the cost of the 340 Build. So when I do come to sell, and as previously mentioned if Im having lots of fun with this 360 then the 340 might get pushed further down the road, but estmates on figures would help the sale I think? Not so many 360's or 340's for that matter in the UK.

rumblefish360 said:
The KB-107 @ zero deck and a .040 gasket will come in at (or right close to a) 9.8-1 ratio. A small cam can cause detonation issues. A thicker head gasket may have to be employed or skip the block decking to zero.

A dome piston will make matters worse.
Click to expand...

Those KB-107's look perfect if I bother going down that road. What are you considering a small Cam here? Would the 340 one be OK? Or maybe a Comp Cams 274H would maybe be better?
 
rumblefish360 said:
3.23’s are fine if the tire stays stock size and it can use a small cam just fine. I would t to much larger than the stock size 340 cam.
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Ok perfect. :)

I can see me reusing the 340 cam. :D No intention of changing the tyre size, although originally the Charger came with 14" Wheels. I do need new tyres though. :( Might put a dent in my piston aspirations, haha.
 
I have that same voodoo cam and it works well in my present 318. It would be fun in a 360. I would go with 3.23 gears and not look back in this instance, a good balanced gear for a four speed and spirited driving. Over here, it's usually an 7-1/4 (a close cousin to a Dana 30), 8-1/4, or 8-3/4 (8-3/4 before 1973) with 2.94 gears. Is the B-W axle a renamed Dana 44 or is it something else entirely?
 
Jadaharabi said:
You realize the 340 oil pan will not work on a 360.
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Thanks for the Heads up. Yes, a very kind gentleman donated a Canton 360 Sump, Pick-up and Dipstick. Never used other that breaking the engine in. From what I gather he had the engine built in the US for his Truck and when it arrived it had the Car Sump installed. So they sent him a new Truck Sump, Pick-up and Dipstick.
 
you asked about 340 cam wear
check the lifters
first keep track of their order!
you can butt two together and they should rock
if they are concave they are junk
you can place the bottom of one against something flat and it should rock and you should not see any light under the center


someone mentioned the 268 comp cam- a fine chevy design by UD Harold
and the 262 lunati voodoo
which has about the same lift with 6 degrees shorter duration
Like advancing the comp intake close point by 3 degrees to build cylinder pressure -(which is not a good Idea as it throws of the other 3 events)
It's a kludge for a to much duration cam
there is no place the voodoo would not outperform the comp especially on a lower compression motor
did OP post up his compression?
The problem with the old 340 cam design is the really long ramps and even with the long duration - not much lift
340 closes the intake late lowering dynamic compression
340 closes the exhaust late leading to intake dilution - which is why it is a smog cam in a late engine- like extra EGR
It opens the intake early allowing blow back , it opens the exhaust early which drains the power stroke- especially a big loss in a low compression motor
the 340 spreads out the overlap (makes it less) to 114 to compensate for these longer ramps which makes the opening and closing points even worse
now when I say early or late I mean compared to a faster acting cam- like the voodoo
did you see the head porting article in HotRod posted recently where they use a custom MM series solid profiles
same basic comparison here
 
Wyrmrider said:
you asked about 340 cam wear
check the lifters
first keep track of their order!
you can butt two together and they should rock
if they are concave they are junk
you can place the bottom of one against something flat and it should rock and you should not see any light under the center


someone mentioned the 268 comp cam- a fine chevy design by UD Harold
and the 262 lunati voodoo
which has about the same lift with 6 degrees shorter duration
Like advancing the comp intake close point by 3 degrees to build cylinder pressure -(which is not a good Idea as it throws of the other 3 events)
It's a kludge for a to much duration cam
there is no place the voodoo would not outperform the comp especially on a lower compression motor
did OP post up his compression?
The problem with the old 340 cam design is the really long ramps and even with the long duration - not much lift
340 closes the intake late lowering dynamic compression
340 closes the exhaust late leading to intake dilution - which is why it is a smog cam in a late engine- like extra EGR
It opens the intake early allowing blow back , it opens the exhaust early which drains the power stroke- especially a big loss in a low compression motor
the 340 spreads out the overlap (makes it less) to 114 to compensate for these longer ramps which makes the opening and closing points even worse
now when I say early or late I mean compared to a faster acting cam- like the voodoo
did you see the head porting article in HotRod posted recently where they use a custom MM series solid profiles
same basic comparison here
Click to expand...


Thank you very much for that detailed yet easy to follow post. I'll have to read it a few times to get my head around it yet though.

So the Voodo Cam is the one to go for if I go down that road instead of just just re-using the 340 Cam and Lifters?

I'll follow your guide for checking the Lifters too, thanks for that. :)

Looking forward to getting stuck in when I get home from working away. :)
 
Is the 340 internally balanced? The 360 is probably externally balance. Is the flywheel the same or do you need a different one like the flexplates. I have no idea but you should make sure your 340 flywheel is compatible.
 
furrystump said:
Is the 340 internally balanced? The 360 is probably externally balance. Is the flywheel the same or do you need a different one like the flexplates. I have no idea but you should make sure your 340 flywheel is compatible.
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The Cast Crank 340's (generally '72's and deffo '73's.) and 360's are both externally balanced. Cheers, though. :) Its things like this that would catch me out. :)
 
furrystump said:
Is the 340 internally balanced? The 360 is probably externally balance. Is the flywheel the same or do you need a different one like the flexplates. I have no idea but you should make sure your 340 flywheel is compatible.
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The 360 flywheel is balanced for 360s only.
68-71. 340 are internal balanced engines and the 72-73 are external balanced.
The 340 external balance flywheels are not balanced for a 360.
 
Jadaharabi said:
The 360 flywheel is balanced for 360s only.
68-71. 340 are internal balanced engines and the 72-73 are external balanced.
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Its an odd Ball Aussie Borg Warner Flywheel. Its originality a Hemi 6 re-ballanced in Oz to Mopar Spec for the 360. US 360 Flywheels dont fit.

Converted Surface Ground and Balanced Flywheel [Small Block 360]

So yes, it was a bit naughty of me to run it behind the 340 but I knew it was not for long as the 340 was needing pulled and rebuild anyway.
 
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