360cu Engine Upgrades

Trivium91

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The heads are your bottleneck. They flow around 185 CFM in stock form. I would put the motor in the low 300's for horse power.

I would take the heads to a shop and have them open the intake valves up from 1.88 to 2.02. Minor port and bowl work to get rid of casting slag and gasket match the intake ports. Don't go nuts. You'll have a solid 350 HP when all is said and done.

Awesome sounds like a decent plan, I assume you are talking Hp at the crank. Ill price it out and hopefully its not too much compared to new heads. I dont feel like i need to spend another $2000+ dollars for new heads as i dont need the power in the car. I have a 1st gen ramcharger being bigger and heavier with 3.23 gears that im saving the the high HP build for that. I have a new 360 crate short block that i want to learn and build on before i dump it in the truck.

Sorry the other question i had was the rocker arms you originally recommended, do i not need them to be adjustable with that cam? i think the link you posted was not.
 

Trivium91

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Im not supe
On the topic of heads, with a stock 2.02 J head using stainless steel,swirl polished nail head valves, would that raise compression over stock steel valves?

Im not usper
What is the rear end gear?, that is the first thing in seat of the pants feel!! Then TC, and don't forget a good tune.

I have 3.91's right now, just looking for more fun, lol. Im sitting around 250-275HP if i were to guess. I also measured the tires, turns out they are only 27" diamater and 10" wide.
 

Duke5A

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Awesome sounds like a decent plan, I assume you are talking Hp at the crank. Ill price it out and hopefully its not too much compared to new heads. I dont feel like i need to spend another $2000+ dollars for new heads as i dont need the power in the car. I have a 1st gen ramcharger being bigger and heavier with 3.23 gears that im saving the the high HP build for that. I have a new 360 crate short block that i want to learn and build on before i dump it in the truck.

Sorry the other question i had was the rocker arms you originally recommended, do i not need them to be adjustable with that cam? i think the link you posted was not.

Yeah, crank HP. I would think about $700 to $1k for the head work. That's what sucks. If you could find alloy heads with a 70ish cc chamber they would run you almost the same amount of money, but every alloy head I know of has a 63-65cc chamber. I'm not sure you can find new heads that won't push your compression into the 11's; which is way too much for that motor.

Yeah, no need to run adjustable rocker arms with a mild hydraulic flat tappet like the XE-274.
 

Trivium91

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Yeah, crank HP. I would think about $700 to $1k for the head work. That's what sucks. If you could find alloy heads with a 70ish cc chamber they would run you almost the same amount of money, but every alloy head I know of has a 63-65cc chamber. I'm not sure you can find new heads that won't push your compression into the 11's; which is way too much for that motor.

Yeah, no need to run adjustable rocker arms with a mild hydraulic flat tappet like the XE-274.

Ouch yeah, hard to justify putting that kind of coin into iron heads. But i guess i will have to make a decision here. With my Pistons and stock stroke...again according to the KB piston specs i would be making 10.9:1 with the chart with 62cc heads. Still too high i imagine even with 91 octane which is what i currently run anyways.

So choices seem to be
-Proceed with Cam swap now and swap pistons/aluminum heads down the road to something more compatible (expensive)
-Find J heads that are ported to 2.2 already (Likely very difficult)
-Have existing heads machined and just pay the money (Cheapest option)

What do you think of these speedmaster heads for maybe down the road? According to piston chart should be a tick below 10.7:1 compression...still too high?

Are used magnum heads worth it? Maybe one day i can pickup some magnum heads for cheap to lessen the blow and get some compatible pistons.

Speedmaster As-Cast Cylinder Heads PCE281-2146
 
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Trivium91

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Yeah, crank HP. I would think about $700 to $1k for the head work. That's what sucks. If you could find alloy heads with a 70ish cc chamber they would run you almost the same amount of money, but every alloy head I know of has a 63-65cc chamber. I'm not sure you can find new heads that won't push your compression into the 11's; which is way too much for that motor.

Yeah, no need to run adjustable rocker arms with a mild hydraulic flat tappet like the XE-274.
Just curious here, why can’t I use thick head gaskets to lower compression ratio on aftermarket heads?
 

M_Body_Coupe

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Just curious here, why can’t I use thick head gaskets to lower compression ratio on aftermarket heads?

Well of course you can...but that will not help you get any closer to having a nice quench volume (space between the top of your piston and the head deck @TDC, believed to be about 0.030-40"). This space introduces just the right amount of turbulence in the chamber to prevent any sort of pre-ignition.

The thinking is that the greater that spece becomes (which is what would happen with a thicker head gasket) the more likely you are to start seeing detonation.
 

M_Body_Coupe

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Ouch yeah, hard to justify putting that kind of coin into iron heads. But i guess i will have to make a decision here. With my Pistons and stock stroke...again according to the KB piston specs i would be making 10.9:1 with the chart with 62cc heads. Still too high i imagine even with 91 octane which is what i currently run anyways...

You know...given that you already have a higher stall converter, and a pretty aggresive gearing out back, you could actully get away with running a bigger cam that will bleed off some of that compression at lower RPM, enough so to avoid detonation just at the time the engine is most susceptible to it.

So here is the thing, as the RPM increase the amount of time available for complete combustion decreases (which is also why you need to advance your timing - you need to ignite the mixture sooner so that all of it has the chance to burn before mechanically the burnt remains needs to be expelled out the exhaust port), this is also why you can in fact get away with running a higher static CR at higher RPM. I'm not saying this is a hard-rule, just a general theory.
 

Trivium91

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You know...given that you already have a higher stall converter, and a pretty aggresive gearing out back, you could actully get away with running a bigger cam that will bleed off some of that compression at lower RPM, enough so to avoid detonation just at the time the engine is most susceptible to it.

So here is the thing, as the RPM increase the amount of time available for complete combustion decreases (which is also why you need to advance your timing - you need to ignite the mixture sooner so that all of it has the chance to burn before mechanically the burnt remains needs to be expelled out the exhaust port), this is also why you can in fact get away with running a higher static CR at higher RPM. I'm not saying this is a hard-rule, just a general theory.

Lots to know, i do appreciate all the information. I found someone retired that claims they would work on the heads for pretty cheap, given the fact I found some interesting information on the stock modified heads in some builds I might just go this route. The link is here if anyone is interested.

Dyno proven 360 packages
 

Trivium91

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Well of course you can...but that will not help you get any closer to having a nice quench volume (space between the top of your piston and the head deck @TDC, believed to be about 0.030-40"). This space introduces just the right amount of turbulence in the chamber to prevent any sort of pre-ignition.

The thinking is that the greater that spece becomes (which is what would happen with a thicker head gasket) the more likely you are to start seeing detonation.
Hmm i also read that a thicker head gasket would also make the intake hard to fit aswell, makes sense that you would need to get creative to seal the intake.
 

Remow2112

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In regards to ignition. Get a MSD 6 digital and a blaster ii coil. Gets rid of the ballast resistor, works with the stock distributor or aftermarket and starting problems will go away. You can also the open the gap on the spark plug. I run .045 gap on mine. Been running MSD in race car and daily drivers for 20+ years best bang for the buck.

Dan...
 

Trivium91

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In regards to ignition. Get a MSD 6 digital and a blaster ii coil. Gets rid of the ballast resistor, works with the stock distributor or aftermarket and starting problems will go away. You can also the open the gap on the spark plug. I run .045 gap on mine. Been running MSD in race car and daily drivers for 20+ years best bang for the buck.

Dan...

Ill look into it but it doesnt look much cheaper than the All in one billet distributor
 

Mikes5thAve

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The MSD 6 or similar ignition module/controller is better then what an all in one would have.
 

Trivium91

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The MSD 6 or similar ignition module/controller is better then what an all in one would have.

ahh gotcha, ill add it to my list of upgrades. That stupid ballast resistor left me stranded once. If i would have known i would have walked to Napa, haha.

Ok so i emailed comp cams, they told me the XE274 comes with the recommended dual springs which would require machining on the top of the heads to fit the inner springs. That being said, the 268 is not substantially smaller and only requires single springs...in fact straight from Comp's website under break in procedures:

“Always remove the inner spring during break-in when using dual valve springs, or if you have a high load single spring, use a lighter spring (110-120 lbs. seat load and 260-270 lbs. open load).”

This suggests the 274 can be used with single high load springs? What springs can we use instead with stock heads? I've asked them but not sure if they are going to reply to this other than saying they recommend dual springs.
 
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M_Body_Coupe

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...This suggests the 274 can be used with single high load springs? What springs can we use instead with stock heads? I've asked them but not sure if they are going to reply to this other than saying they recommend dual springs.

Take a look at the attached charts. Find a spring that fits your needs...
 

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Trivium91

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Take a look at the attached charts. Find a spring that fits your needs...
So i guess the idea is to match a single spring as close to what the recommended spring is? Comp Cams got back to me BTW, said that with single springs i wont be revving over 3000 RPM's thats why i need dual's, i think that's ridiculous but ok. I've always heard single springs are fine for anything under 0.500" lift and really the XE 274 should be no exception since the lift is not that crazy on it being just under 0.5"
 
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jasperjacko

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that cam may have a faster ramp which would need a stronger spring
 

Trivium91

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True, however one can get stronger single springs...why does it need to be duals?
 

M_Body_Coupe

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True, however one can get stronger single springs...why does it need to be duals?

Well, think about what something like a dual (or even triple) spring does for a valvetrain. It all of a sudden allows you to damped various harmonics in the system that a single spring setup simply can not keep up with, or flat out will not be able to handle.

While in a very simple install (mild cam - where this is NOT necessarily a question of LIFT, but rather how aggressive the ramps are) a single spring may work, in a more complex setup where the ramps have special designs and where engine RPM levels are high (and get there very fast) you end up having to run multiple springs.

Also, remember this: we are talking here about big amounts of energy right? So what does a spring do? It absorbs a lot of that energy and turns it to heat (I'm oversimplifying, but that's the general idea)...heat is what will eventually weaken the spring. If on the other hand you "spread the wealth" over a couple of springs they will simply live longer.

If you need to go with a single spring for your application, find one in that list that:
1) has the correct ID and OD sizes to fit into the stock spring seat on the head
2) has the correct length so that it allows for the full lift (and leaves a little room) and works with the installed height of the valves
3) has the correct spring rates to control the valve motion (this is the xxx lbs rating)
4) allows you to run your choice of the valve seal (are you going to cut the guides for positive seals, or leaving things up to the factory install?)
 

Trivium91

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Well, think about what something like a dual (or even triple) spring does for a valvetrain. It all of a sudden allows you to damped various harmonics in the system that a single spring setup simply can not keep up with, or flat out will not be able to handle.

While in a very simple install (mild cam - where this is NOT necessarily a question of LIFT, but rather how aggressive the ramps are) a single spring may work, in a more complex setup where the ramps have special designs and where engine RPM levels are high (and get there very fast) you end up having to run multiple springs.

Also, remember this: we are talking here about big amounts of energy right? So what does a spring do? It absorbs a lot of that energy and turns it to heat (I'm oversimplifying, but that's the general idea)...heat is what will eventually weaken the spring. If on the other hand you "spread the wealth" over a couple of springs they will simply live longer.

If you need to go with a single spring for your application, find one in that list that:
1) has the correct ID and OD sizes to fit into the stock spring seat on the head
2) has the correct length so that it allows for the full lift (and leaves a little room) and works with the installed height of the valves
3) has the correct spring rates to control the valve motion (this is the xxx lbs rating)
4) allows you to run your choice of the valve seal (are you going to cut the guides for positive seals, or leaving things up to the factory install?)

Makes sense, I'm bring the heads to a machine shop and hoping he can pick the springs for the cam I want. Turns out he can order the cam and all the parts and will machine out the heads for me...make it a sort of package deal.
 
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