340 cam for 318

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Baggs said:
Currently 4.11. 727 transmission. No power brakes, only vacuum I think, will be for the distributor.
Here’s a screen capture of the one I was looking at.

View attachment 1716340170
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Nice, like!
Garrett Ellison said:
Your best bet for your engine, just make sure you have enough room for the valve lift.
Howards Cams, Hydraulic Flat Tappet Camshaft, Chrysler SB 273-360/318, 208/214 @ .050, .479/.494, 110 LS - Competition Products
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It’s only a few degrees larger than a OEM 360 cam. “Small”
junkyardhero said:
i personally think that's a buncha lift for a low comp 318 with stock small valve heads and a restrictive intake
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Lift has no bearing on any concerns but will certainly aid in power.
The OEM heads flow well to 500 lift. The head can handle it and the engine won’t go down on power.
junkyardhero said:
(he's gonna run a street master and something like a 500cfm carb).
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I hope not! Terrible intake, carb to small
junkyardhero said:
the duration is good,
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He can get away with another 8-10 degrees @050 easy without ill effect. Been there done this.
junkyardhero said:
the 110 is good but the combo
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Not really. If he had a 318 w/a 2.02, id says yes.
He can use a cam with a LSA around 108 / 107

junkyardhero said:
isn't there to take advantage of all that lift.
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Not true
junkyardhero said:
if i was rolling howards i'd be keen on the street force uno

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As I said above, 216/218@050 can be done. It’s power is just a few hundred rpm off of idle, works with a stock converter, even more so with 4.10’s!

An OEM 4bbl or Performer intake works well here w/a 600 cfm carb.

IMO, any cam under 210@050 is a weeny cam with the gear ratio and intended driving conditions listed by the OP.

PRH and Fishmen gave nice cam recommendations.
 
Baggs said:
Tires will be 15 inch, probably in the 205-15 range, maybe 215. So not tall. 60 series if available.
Good drivability, I don’t need/want a rumpity cam.
No strip time will be seen. Possibly some spirited driving, but not along side of someone.

230/240 HP is the most I’d want in this truck.

I may change the rear end though, but will start with what I have.
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Those tires spec out right around 26”’s. A 60 series tire equal is approximately a 235/60/15. Do some research on the factory tire size and what is available. At Summit racing, the tire diameters are normally listed with each tire listed.
 
rumblefish360 said:
Nice, like!

It’s only a few degrees larger than a OEM 360 cam. “Small”

Lift has no bearing on any concerns but will certainly aid in power.
The OEM heads flow well to 500 lift. The head can handle it and the engine won’t go down on power.

I hope not! Terrible intake, carb to small

He can get away with another 8-10 degrees @050 easy without ill effect. Been there done this.

Not really. If he had a 318 w/a 2.02, id says yes.
He can use a cam with a LSA around 108 / 107


Not true


As I said above, 216/218@050 can be done. It’s power is just a few hundred rpm off of idle, works with a stock converter, even more so with 4.10’s!

An OEM 4bbl or Performer intake works well here w/a 600 cfm carb.

IMO, any cam under 210@050 is a weeny cam with the gear ratio and intended driving conditions listed by the OP.

PRH and Fishmen gave nice cam recommendations.
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i respect your experience and opinion, but i'm only giving my best recommendation based off of the parameters the OP has set.
 
With 4.10 gears, I'd run an Eddy Torker 2, Holley Street Dominator, or Weiand Xcellerator single plane.
 
YY1 said:
I bet factory replacement 9.2:1 pistons are not terribly expensive.
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They are non-existent, that's why people have to hang onto the originals when the come across them.

When they are gone, they are gone......

20230119_164429.jpg


Just like all the reman 302 Closed Chamber Heads, gone, gone, gone.....

1020161100.jpg



☆☆☆☆☆
 
YY1 said:
I bet factory replacement 9.2:1 pistons are not terribly expensive.
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Well yeah, since they have to be a custom piston, they are, because nobody offers them off the shelf. So it's either that, or you luck and find some good used or NOS and good luck with THAT if you need them over sized. Talk about hen's teeth.
 
George Jets said:
They are non-existent, that's why people have to hang onto the originals when the come across them.

When they are gone, they are gone......

View attachment 1716340256

Just like all the reman 302 Closed Chamber Heads, gone, gone, gone.....

View attachment 1716340257


☆☆☆☆☆
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Well no, you can call Ross and they'll whittle you some out. But you know....$$$$$$ Kinda defeats the purpose of "budget". lol
 
Baggs said:
I’ll mention I’ll be riding the lifters, unused, but new 25 years back. I’d trust them more than a new set of lifters.

I’ve never heard a bad word about Howard cams either.
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That Howards linked too is a decent grind, except for the 112 LSA. You NEED a 108 or even a 106 LSA. What I would do is send your old core to Oregon Cam Grinders and let them grind something similar to the Howards grind but on a 106. If you put something on a 112 in that, you're not gonna like it.
 
Well, I think I mentioned it, the 4.11’s I have now is just to get it moving. After kinks are worked out I move to a 3.25/3.5 rear end.

But I only have so much room under cover, so needs to be planned when the time comes.
 
Also, I thought about it the past two days, probably will send my cam out and see exactly what it is.
 
"Factory" 9.2 pistons are NOT "custom".

67-69 318 was 9.2 as were the LA roller 318.
 
Rock Auto shows 1986 318 pistons for $25 or less each.
 
YY1 said:
"Factory" 9.2 pistons are NOT "custom".

67-69 318 was 9.2 as were the LA roller 318.
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I didn't say they were. I said you have to GET custom because nobody offers those anymore. Rockauto does not have the 68-69 pistons. The later engines you describe had the compression because of the 302 head castings. The compression height on their pistons was shorter than the 68-69 pistons. Nobody makes those. So yes they would have to be cu$tom.
 
Incidentally, those Wiseco pistons will get 12.25:1 at zero deck height with a 58cc head. LOL
 
Baggs said:
In my first thread, I’ve decided to just square the deck and get it to 9.58 height.

This 318 will be 8:1 SCR

But in that thread talk of a 340 cam on a 318.

Doing some Google says the earlier 340’s were 10.5:1 SCR. Later ‘70’s were 8.5:1.

I also noticed much different cam specs on both.

I’d assume, but want to verify, used the ‘73? cam with my SCR?
Thanks,
Mike
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As for a 340 cam in a 318, we have all done it. Some of us have even paired it up with 360 heads, and their 318 ran great. In 1972 the advertised Comp ratio for a 318 was 8.6:1 and a 340 was 8.5:1. These numbers seem right to me, since the compression height is the same for 1972 318 and 340 pistons and the 72 J heads had slightly bigger chambers. That being said, you have to measure your own compression ratio with what you have in your hands. You can also mill the heads to gain compression and mill the intake side of the heads to keep everything in the right relationship to the intake. The 340 cam was the same as earlier 340 cams except the 1968 four speed 340 cam. Are there better cam grinds available today? Probably, but I do not go cheap on a cam or lifters. The cam is a major determinant on how the engine will perform. I used to run Isky cams and lifters, never a problem. Now, I just call Jim at Racer Brown and tell him what I am working on and what I want. He figures what to make and I buy it. Other cam grinders can do the same. Why go off the shelf, sounds like you have time to think this one out.
 
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I remember when I wanted to add some ooommph under the hood and bought a 318 with plans to build it. I then started looking for pistons to help increase compression. .. :BangHead:
I was running everything by my machinist and eventually he offered/sold me a fresh machined 340 with used pistons, new bearings for basically the same price the 318 pistons would have cost me lol.
Those Wisecos you linked would be approx $1000 Canuck pesos lol.
RustyRatRod said:
Just put these in it. They can get 022" deck clearance with no milling and zero deck height if you want.
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4spdragtop said:
I remember when I wanted to add some ooommph under the hood and bought a 318 with plans to build it. I then started looking for pistons to help increase compression. .. :BangHead:
I was running everything by my machinist and eventually he offered/sold me a fresh machined 340 with used pistons, new bearings for basically the same price the 318 pistons would have cost me lol.
Those Wisecos you linked would be approx $1000 Canuck pesos lol.
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That was a win/win for sure. But yeah, the Wisecos ain't cheap. If I had the money, I'd do somethin stupid and build a W2 headed 318 with the Wisecos in it. lol
 
I thought this thread was locked as well:)
I didn’t want to scroll back, but there was mention of ‘72 CR.
I can assure you no way I’ll be at 8.6? I think it was SCR.
With the .030 pistons it has now, 4 corner measurements sow .105-.095 with them at TDC. But that’s not off a centerlines, just deck to then ends on each side.
Using wallacaraxing CR calculator that take bore size into account, I’d need the decks at 9.585 vs 9.6 to be close to 8.1:1 SCR.
I have open chamber heads,
I could get the casting numbers but from what I gathered here and via the web they are “spec’ed at 72 cc’s.
Maybe the 8.6:1 was with a closed chamber head?

And after @junkyardhero (and others) explained to me LSA and cylinder pressure I’ll be looking in the 106-108 range with a grinder.
 
Baggs said:
I thought this thread was locked as well:)
I didn’t want to scroll back, but there was mention of ‘72 CR.
I can assure you no way I’ll be at 8.6? I think it was SCR.
With the .030 pistons it has now, 4 corner measurements sow .105-.095 with them at TDC. But that’s not off a centerlines, just deck to then ends on each side.
Using wallacaraxing CR calculator that take bore size into account, I’d need the decks at 9.585 vs 9.6 to be close to 8.1:1 SCR.
I have open chamber heads,
I could get the casting numbers but from what I gathered here and via the web they are “spec’ed at 72 cc’s.
Maybe the 8.6:1 was with a closed chamber head?

And after @junkyardhero (and others) explained to me LSA and cylinder pressure I’ll be looking in the 106-108 range with a grinder.
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Stop using the web. 318 heads unmilled are 68 cc per chamber. 72 cc chambers are 340/360 heads. They usually only lock a thread if someone takes the discussion off the rails.
 
If you’re thinking about a regrind, it’s generally not a good idea to try and alter the lsa more than 2 deg from whatever it currently is.

It seems unlikely that “318” heads would have chambers as big as 72cc.
But, just measure to know for sure.
 
PRH said:
If you’re thinking about a regrind, it’s generally not a good idea to try and alter the lsa more than 2 deg from whatever it currently is.

It seems unlikely that “318” heads would have chambers as big as 72cc.
But, just measure to know for sure.
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Yeah, i had one reground by Bullet and they weren’t too excited about spreading the lsa.
I got a degree out of it haha. 110 to 111.
They wanted to preserve base circle it seemed.
 
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