I was running mine and they worked perfect cracked. I wouldn't put springs on them that had 150+ seat pressure and rev it all day to 7k.
340 heads on 360?
- Thread starter Elís Máni
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If were talking 360 heads, I know of none. X, J, and O were open chamber also. Now, as you know, cc's will differ slightly, but the concept of design will be the same.
I'll just add this: A typical smog style 360 head (lets say 1977 360 heads) will perform very well. People buy X or J's thinking they've changed the world with their motor. If 2.02's are installed in the smog heads, and especially if mild bowl work is done even by a home porter, wow can these heads work.
- Let me add, 2.02's are not the tell-all either, as 1.88 is very serviceable in a milder street build.
Fair enough as to the OP's question, but We pretty much covered that up front. That's not the way CB worded it in His post, and the OP, having little to no experience may
not know the 302 & subsequent versions exist. Whether or not He is ever going to use them, it is simply information, no need for someone to take it personally..............
As far as doorstops,....lol!
No, you went off topic about heart shaped chambers as this was a discussion about 340/360 heads.
Where exactly did you state that this was only regarding the 318/302 head... Yeah thought so... It's dead wrong and sure didn't apply to the 308 head. Wrong is wrong!
360 Heads were open chamber until the magnum swap over which is exactly what I wrote in context to the discussion.
Where exactly did you state that this was only regarding the 318/302 head... Yeah thought so... It's dead wrong and sure didn't apply to the 308 head. Wrong is wrong!
360 Heads were open chamber until the magnum swap over which is exactly what I wrote in context to the discussion.
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Lol, noo, the topic was getting a bump in squeeze from changing heads. The OP asked if the ones He transferred did so, they did not, (unless they were mowed). Your post
didn't get the red X for the 308 inclusion Bud, it got it because it started "All the heads", not "All 340/360 heads". True I omitted the casting #'s & the fact they
were 'teener heads, but they are the only non-aftermarket option for a good swap for squeeze, even if they limit max power. The abysmal compression of that 360, made
worse if the OP threw typical fel-pro's on it, would certainly respond with an improvement everywhere but the upper mid-range & up. The OP doesn't need to be a genius
to port match them & widen the pinch some, just diligent & cautious.
He seems concerned that putting 2.02's will be too $$$ for Him, so I'm looking for an economical solution for improvements. If He can find a set cheap & they check-out
for cracks etc., He may be limited to 300 or a tick less, but it'll drive & idle one hell of a lot better. Not here for a weenie waggin' contest.....................
Not necessarily. But the second you say cracked head, everybody runs like the house is on fire. The Magnum head, is also prone to cracking as well, but they remain in service on running engines for hundreds of thousands of miles and driver/owner never even know’s they’re cracked.
Of course your machinist will. It work or port a cracked head to start with so good luck on finding a sound head to start with. It may or may not be a challenge to find a cracked head.
If I was building a 360 and I had OE heads, the worth of a 2.02 would be dependent on two factors, money, purpose of the build.
The 2.02 would pay off fine from a certain perspective, even in mild builds. I do t see or have felt the worth. The 2.88 will perform well for mild street machines. When and where the pay off of a 2.92 is May not always be a fact of the Dyno because as I said earlier the bottom two lines are cost and purpose of the build.
If your seriously looking for hp from the OE heads, then you would be seriously looking at not just 2.02 valves but also well designed valves in well thought out seat and carved out ports.
Years back I did a stupidly mild 318 build up with just bolts one to a basically dead on its heels smog 318 and managed high 14’s on stock tires. 318 will run showed some basic build tips and porting. Stock small valves can and will do OK.
Scientifically, you can weigh things out. Your wallet may stop you from certain upgrading routes so be creative with other parts your going to purchase anyway.
The 2.02 would pay off fine from a certain perspective, even in mild builds. I do t see or have felt the worth. The 2.88 will perform well for mild street machines. When and where the pay off of a 2.92 is May not always be a fact of the Dyno because as I said earlier the bottom two lines are cost and purpose of the build.
If your seriously looking for hp from the OE heads, then you would be seriously looking at not just 2.02 valves but also well designed valves in well thought out seat and carved out ports.
Years back I did a stupidly mild 318 build up with just bolts one to a basically dead on its heels smog 318 and managed high 14’s on stock tires. 318 will run showed some basic build tips and porting. Stock small valves can and will do OK.
Scientifically, you can weigh things out. Your wallet may stop you from certain upgrading routes so be creative with other parts your going to purchase anyway.
replicaracer43
Grumpy Old Man
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Another good compromise in upgrading a 1:88 head is to go to the chevy 1:94 valve, if not wanting or needing a 2:02. It provides a way to get more use out of a slightly sunken 1:88 seat
Yes, and it works well.
ir3333
Well-Known Member
Mopar sm blk head flow stalls around .485 lift and the 1.88" intake valves will handle this.
It doesn't seem 2.02" intake valves could be beneficial unless there is both port work and an increase in cam lift.
... 1.92" valves should work great if the original 1.88" valves have sunk no more than .040
It doesn't seem 2.02" intake valves could be beneficial unless there is both port work and an increase in cam lift.
... 1.92" valves should work great if the original 1.88" valves have sunk no more than .040
ir3333, your kind of right. The 2.02 offers more curtain area of air and fuel. It isn’t much of a gain, but it’s there. Will you notice it?
Will the butt Dyno say “Yaaaa!”
I doubt it.
The factory wouldn’t waste the time, effort and cost doing this if there wasn’t something there.
Will the butt Dyno say “Yaaaa!”
I doubt it.
The factory wouldn’t waste the time, effort and cost doing this if there wasn’t something there.
d1970
TODAY IS A GOOD DAY TO HAVE A GOOD DAY
The factory wouldn’t waste the time, effort and cost doing this if there wasn’t something there.
stock head with 1.88 valve - 185 cfm range, 2.02 valve - 215 cfm range. But if you fully port that stock head with the 2.02 valve you could get it flow in 280 cfm range so you could take advantage of a larger camshaft with more lift and better springs allowing more fuel and air to enter the combustion chamber.
stock head with 1.88 valve - 185 cfm range, 2.02 valve - 215 cfm range. But if you fully port that stock head with the 2.02 valve you could get it flow in 280 cfm range so you could take advantage of a larger camshaft with more lift and better springs allowing more fuel and air to enter the combustion chamber.
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ir3333
Well-Known Member
I agree!
The factory also rated the compression at 10.5 :1 on early 340's that were actually in the
mid 9's.This allowed racers to cut the heads,decks and build to 10.5:1 and be NHRA legal.
Port work would certainly take advantage of the bigger 2.02" intakes in the early heads.
The factory also rated the compression at 10.5 :1 on early 340's that were actually in the
mid 9's.This allowed racers to cut the heads,decks and build to 10.5:1 and be NHRA legal.
Port work would certainly take advantage of the bigger 2.02" intakes in the early heads.
ir3333
Well-Known Member
Ma Mopar probably had an eye on the competitions' smallblocks and would certainly build equal or better.
Rumble points out a small gain with the 2.02's and i would agree at the big end but maybe not on the street?
Rumble points out a small gain with the 2.02's and i would agree at the big end but maybe not on the street?
Small gain on the street.
But as you pointed out a good multi angle valve job, porting, sounds like it’s ready to rock ‘n’ roll.
But as you pointed out a good multi angle valve job, porting, sounds like it’s ready to rock ‘n’ roll.
If you took the 73 340 heads, cam and intake and put them on that 80's 360 block what you have done is build a 74-76 360 4 Barrel motor like was in the dusters and darts and the roadrunners and the 360 challengers and cuda.
the 360 motor was put into the car around ''96 and then taken out of the car again in 2007 (i have some pictures of it witch i will include). it has a new edelbrock intake and four barrel carp (not sure what kind). but i have no idea if it has mew cam cranck or pistons allthough i suspect that it might. the guy who took it out in 07 does not remember what he did to that exact engine.
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Nice lookin' setup You've got there! Any chance a shop that might have done the machine work may have a record/invoice of what was done? It'd be great if it's got 9:1
slugs in it!!
I don’t ever remember seeing a P/S bracket set up like that. Looks pretty cool.
thats the thing they don't have anything like that. Have to open the engine and try to find out since the guy who did it does not remember anything.
Oh! CRS syndrome!
Can’t
Remember
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Can’t
Remember
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See if someone that techs class cars for compression will check it for You or even lend You the setup to cc it together. Checking the cam should be easy for You to do, just
check out Comp Cams how-to on You Tube, and there is a sticky at the top of one of Our forums here for a download/printable degree wheel.
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