Which Camshaft For This Brute?

[70bigblockdodge]

No not at all. Not all factory cams have wide LSAs like US engines. The 850 Morris Mini had a factory cam of 230* adv duration......& was ground on a 107.5 LSA. You can be sure it had a smooth idle. That was the smallest cam. Bigger engines such as the Morris 1100, Sprite 1300, Cooper S had cams with more exh duration but the same 107.5 LSA. These were factory cams. Some aftermarket cams were ground on 102.5 LSA

And the valvetrain is so light in those engines the ramp can be incredibly fast. A cam in block with 1.5+" dia. valve springs an 2+" intake valves you cannot get a ramp with low duration to get to a decent lift. Stock factory cams never had the lift available that is "normal" now. Hence just push the LSA up and you can have both. Will it make max power? No, he is asking for a driver.

 

[Dodge Bros]

FWIW…That 128 rule is an overlap driven equation to calculate the ideal LSA from the valve diameters and cubic inches for single pattern cams. It is blind to everything else about the engine. Like if you have log manifolds, and want a mild street engine that needs to run on pump gas. He uses a 131 rule for chanted heads for single pattern cams. BBC’s.

Vizard is big on single pattern cams.

The cam needs to be big enough to keep the cylinder pressure held back for the intended fuel. Vizard talks about that also. The people that use Vizard’s 128 rule for small cam pump gas engines often seem to ignore Vizard’s cylinder pressure guidelines, and end up with a very average running engine that only run on race gas.

 

[haywire 440]

And the valvetrain is so light in those engines the ramp can be incredibly fast. A cam in block with 1.5+" dia. valve springs an 2+" intake valves you cannot get a ramp with low duration to get to a decent lift. Stock factory cams never had the lift available that is "normal" now. Hence just push the LSA up and you can have both. Will it make max power? No, he is asking for a driver.

Yes the cam needs to be a driver.

I’ve been keeping up on the dialogue with much interest. Some terms are starting to get clearer and understandable. There is a lot that goes into selecting the “perfect” cam.

The 4 camshafts originally listed were:

1. The Stock ‘65 300L stick that was pulled out of the motor with the 268 duration and overlap of 48. I thought of re-using it but the lifters had a concave bottom and the engine never ran for me, plus most folks thought that using it was not an option.

2. Is the Melling Camshaft that is currently in the short block. Duration of 206, intake and 209 exhaust. No overlap is listed.

3. Is the recommended cam of the the Chrysler 300 International club replacement. CamCraft’s 210 duration with a -10 overlap. At first I thought it was an exact duplicate of the stock cam but apparently not. Though some might think it’s a good choice, I haven’t bought it.

4. Is a camshaft that is old stock, new, sitting on my shelf for years. A Com Cams so-called RV cam with a 224 duration and a 106 plus a 106.0 intake center line.

I reckon much of my initial confusion was with the fact that the specs are not uniform. Second the installed cam was sourced through the machine shop after our discussion of what I was looking for, basically a stock performance 300L.

This is a low lift and for most here a moderate power engine that needs to be civilized on the street.

It’s humbling to gain knowledge on this subject. Certainly it’s not overlooked that some pointed to calling a cam maker, like Hughes.

 

[Geoff 2]

In one of DVs videos, he says he tested 19,200 cams, many if not all for Crane cams. He also says he has a dyno, not an opinion. And as a result of this, if you look at later Crane catalogs after DVs testing was completed, the trend was tighter LSAs compared to earlier Crane cams.

I have seen a few cam comparisons where just LSA was changed. In every case, tighter LSA made more tq & sometimes more peak hp. This was from mild to wild & different engine families. On the mild side, Richard Holdener compared 3 cams in an LS engine, forget the exact LSAs but I think it was 108, 110 & 116. As expected, the 108 made more tq everywhere in the mid range.....& very close at the top end. You can find it on the net, done a few months back.

To the wild, a 350 Chev with big Isky cams making 580 hp.
Identical cams tested except for LSA, 106, 108, 110.
The 110 made 3 hp more than the 106, 583 v 580hp. But the 110 average tq through to 7000 rpm was down 23 ft/lbs compared to the 106.
I know which one I would be using....

If I find somebody who has tested more cams than DV, I will take their advice......

 

[70bigblockdodge]

FWIW…That 128 rule is an overlap driven equation to calculate the ideal LSA from the valve diameters and cubic inches for single pattern cams. It is blind to everything else about the engine. Like if you have log manifolds, and want a mild street engine that needs to run on pump gas. He uses a 131 rule for chanted heads for single pattern cams. BBC’s.

Vizard is big on single pattern cams.

The cam needs to be big enough to keep the cylinder pressure held back for the intended fuel. Vizard talks about that also. The people that use Vizard’s 128 rule for small cam pump gas engines often seem to ignore Vizard’s cylinder pressure guidelines, and end up with a very average running engine that only run on race gas.

Agreed, the 128 is inline valve wedge. He tweaks it down to 127 on small block ford because of valve angle. There are variables to it. My Bullet solid flat tappet has a LSA of 107 it is by far not a daily driver cam and there is no way you can cut the duration to small enough to reduce overlap, and still get to .578 and .587 lifts.
This is the reason OEMs went to roller cams in stock engines is to get the lift to work the better modern heads and still have docile engine
I think that using the DV 128 rule as a starting point then roll it back(compromises) for drivability.

 

[haywire 440]

Here’s a simple basic question on this Melling cam and the Specs Sheet. What is the LSA? It is not listed with all this information. The Center Line is but I’m guessing that is not the LSA. Would it be attainable through math of the various openings and closings of the intake and exhaust valve? Or is it plainly not listed here?

 

[Dodge Bros]

110* intake CL+116*exh CL =226*

226*/2=113*

 

[haywire 440]

I had just found the answer on the Summit catalog, @Dodge Bros
Thanks!

Melling SPD-11 - Melling Stock Replacement Camshafts​

what is the lobe separation of the Melling SPD-11 STOCK CAMSHAFT?
1answer

Answer this Question

1. aredd
   · a year ago
   
   The Melling SPD-11 replacement camshaft has a lobe separation of 113 degrees.

 

[Dodge Bros]

I did some quick number crunching for you on some computer software and I came up with about 9:1 compression with the pistons mentioned. Well short of 10. The camcraft cam was showing it would require 92 octane fuel at 9:1…if it were 10:1 that shoots that cam well over 200lbs cranking pressure and up toward 100 octane. That is even installing it straight up at 110. The guys using it must be running it in low compression 440s?

That Comp 270 cam and the SPD11 are both calling for 89 octane at 9:1 according to the numbers I am seeing. More than likely the SPD11 could possibly run on 87 octane with it’s cam events spread out the way they are and less overlap than the other two cams. The 270 comp probably won’t go much below 89 octane without an extraordinary tune. Of those 3 cams I think your making a good choice. At 9:0 a 6400 summit ..214/[email protected]…would have been a good choice for a slight upgrade over the SPD11. Probably what I would have picked for a cheap upgrade over the 11. People put it in big block 4x4 pickups, i have lost count of all the engines I have done with that grind. It is somewhat smaller than a magnum cam with less seat timing. If the engine was actually 10:1 the next summit cam bigger (6401 or similar cam, would probably have been needed to keep the VE down to run on pump gas. Hughes cams are usually big on lift and usually narrow up the LSA quite a bit, not sure I would want that extra wear and tear on the valve terrain or the snotty idle on this. Hughes know there stuff though, he probably wouldn’t over cam it.

I would prefer to have the engine at least make it to 5000 before it lays over, that SPD11 will make it close to 5K. I did a cam in a 4x4 truck for a friend that pulls 15k trailers, he shifts at 5500. 4 speed with 3.23s and a 413, SPD11 is as small of a cam I would ever use with the compression sitting at 9:1.

 

[haywire 440]

This is my post from a few days ago on the compression height of the old 413 pistons, @Dodge Bros

“The stock compression is 10 to 1. Here are some specs on the pistons. The original compression height of the factory piston is 2.085. The compression height of the replacement pistons are advertised as 2.015 but I didn’t measure that before the 413 was put together.
I did measure 2 of the removed Chrysler and they both measured 2.022. So I believe they were lower in the cylinder to begin with.
The engine and heads were just decked enough to straighten and clean.”

I just checked how low the new .030 pistons are in the cylinders and with a feeler gauge and it was .050. The head gasket that comes with that rebuild kit is a .040 thickness but I have looked into getting some .020 head gaskets from Summit. I guess a dial indicator would maybe be more accurate as … if the stock height is 2.085 and the new pistons 2.015 the difference should be .070 but like I said I, or the machinist did not measured the new pistons.

I was studying Hughes cam selections and unless it’s a custom grind all the valve lifts are at or above the Comp Cams RV cam, something like.473 and higher. It seems my stock valve springs may not be appropriate then.

 

[Dodge Bros]

The 10:1 factory estimate was over rated quite a bit.

I estimate the compression is 9.2 if the heads were trued up with the pistons .050” down. Sounds like the block was decked and squared if the pistons were .050” down with a 2.015” compression height. I would expect the piston to deck height would be closer to .070” with a stock untouched block. That 9.2 is assuming the heads are 79 cc. We have a set of 1965 516 heads that measure 81cc. Not many of the Hughes cams work with stock factory springs. Hughes cams are Howard’s grinds.

View attachment 1502810

 

[451Mopar]

Yes the cam needs to be a driver.
I’ve been keeping up on the dialogue with much interest. Some terms are starting to get clearer and understandable. There is a lot that goes into selecting the “perfect” cam.

The problem is there is no "perfect" cam. Everything is a compromise, and how you prioritize what is important to you.

I looked at the head flow numbers on Stan Weiss' chart, and stock, they don't look good.
Stan Weiss' - Cylinder Head Flow Data at 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

I got interested, so I started looking at the actual numbers.
I just started the calculations, so I will try to finish tomorrow.
I need to double check the compression ratio / piston heights.

On your stock valve springs, have you checked the seat and open pressures?
One guy wanted me to install the Mopar 292/0.509" cam with his stock valve springs that only had 70 pounds of seat pressure.
I had some 440 source springs off a stealth head that I used.

 

[haywire 440]

The problem is there is no "perfect" cam. Everything is a compromise, and how you prioritize what is important to you.

I looked at the head flow numbers on Stan Weiss' chart, and stock, they don't look good.
Stan Weiss' - Cylinder Head Flow Data at 28 Inches of Water -- DFW / FLW Flow Files for use with Engine Simulation Software

I got interested, so I started looking at the actual numbers.
I just started the calculations, so I will try to finish tomorrow.
I need to double check the compression ratio / piston heights.

On your stock valve springs, have you checked the seat and open pressures?
One guy wanted me to install the Mopar 292/0.509" cam with his stock valve springs that only had 70 pounds of seat pressure.
I had some 440 source springs off a stealth head that I used.

I did not check the seat or open pressure. The machine shop did not mention those numbers but I could call and ask them.

I did find something new about the heads after getting them back last week. One of Uncle Tony’s Mopar videos showed him taking a straight edge across the tops of the 8 valve stems to check the heights of those and to match them up with stock Mopar push rods to balance out some imperfections. I wasn’t sure if that was necessary with the hydraulic lifters but it showed the quality control of mass produced automotive parts.

Well the heights of mine on both cylinder heads are split 4 high, 4 low. The difference is intake and exhaust valves. The shop installed hardened seats.

I just measured the difference and it’s all the exhaust valves that are shorter. One head the differences vary from .017 to .020 and the other head was between.025 and .036. This has to increase the spring pressure “closed” on the exhaust valves. A bigger concern is how the hydraulic lifters are going to react to this difference.

I have not measured the stock push rods yet but in Uncle Tony’s video he obviously didn’t address this subject.

I liked that Stan Wiess information.

 

[padam]

I did not check the seat or open pressure. The machine shop did not mention those numbers but I could call and ask them.

I did find something new about the heads after getting them back last week. One of Uncle Tony’s Mopar videos showed him taking a straight edge across the tops of the 8 valve stems to check the heights of those and to match them up with stock Mopar push rods to balance out some imperfections. I wasn’t sure if that was necessary with the hydraulic lifters but it showed the quality control of mass produced automotive parts.

Well the heights of mine on both cylinder heads are split 4 high, 4 low. The difference is intake and exhaust valves. The shop installed hardened seats.

I just measured the difference and it’s all the exhaust valves that are shorter. One head the differences vary from .017 to .020 and the other head was between.025 and .036. This has to increase the spring pressure “closed” on the exhaust valves. A bigger concern is how the hydraulic lifters are going to react to this difference.

I have not measured the stock push rods yet but in Uncle Tony’s video he obviously didn’t address this subject.

I liked that Stan Wiess information.

As far as the springs go, you have to set the installed height using shims under each individual spring.

 

[451Mopar]

That is alot of variance in valve stem height. The machine shop should fix that. They will usually take some metal off the valve valve stem tips to get them the correct height than sink the valve further into the cylinder head, so all the springs would need to be shimmed to the correct install height. Having the valve stem tips different lengths will cause problems with lifter pre-load using the same length pushrods. I use pushrod length checker and order custom length pushrods for most builds as the engines are usually decked and have aftermarket heads.

 

[451Mopar]

Quick question? Headers or exhaust manifolds?

 

[451Mopar]

I checked the numbers, and then ran some simulations in Dynomation 6 Pro-Tools, with a few different cams and LSA's.
Using the iterator, looking for maximum area under the torque curve to 4000 the sim liked the narrow LSA, usually around 104 to 105, installed around 100, with durations around 220, idle to around 2500 RPM was good, but the sim was showing the power drop off quickly after that. I didn't check the DCR/cranking pressure, but likely pretty high with the cam advanced so much.
Then iterated for max area under power curve to 5000. This tended to like more duration and wider LSA. It showed some power increases above 3000 RPM, but low end took a big hit.
The head flow seems to be the big cork. Pretty easy to get 400+ ft/lbs of Torque, but any of the cams with decent low end torque are showing around 280 HP. Even the large cams were not breaking 300 HP.
The sim did seem to like the high rate of lift Hughes cams. The extra lift likely helped the head flow too.
I liked the power curve of the SER1620BL-12, and it is a cam I am using in a 9.5:1 compression 360.
The larger SER2226BL-10 only showed about 5 HP more at 4000 RPM, while being a bit lower in torque below 3500.
The sim was modeling with headers. It won't do wave-action sim with manifolds.
I set the sim to do the filling/emptying so I could compare with the manifolds, and the sim actually liked the SER1620BL-12 slightly more?
Actually the power curves were almost the same to 3000 rpm, and then the 1620 showed more torque/power from 3000 to 5000 where the lines crossed.
At 4,000 RPM the sim showed 287 HP vs 277 HP for the larger cam? Torque was 447 @ 2,500 RPM for both cams.

 

[451Mopar]

This morning, I plugged in the valve sizes and flow numbers (as advertised [email protected]") for the Edelbrock RPM head.
I left the compression ratio the same at 9.5:1, and everything else the same too with the SEH1620 cam.
Power from 1000 to 2000 RPM about the same, even at 2500 RPM the Edelbrock was only up 4 HP.
Then the numbers for the Edelbrock took off where the stock head struggled.
Peak numbers 400 HP @ 5,500 RPM, and 465 Ft/lbs @ 3,500 RPM.

 

[haywire 440]

Quick question? Headers or exhaust manifolds?

I’m using the stock log manifolds with duel exhaust and near original mufflers.

The valve height difference, is puzzling and will contact the shop.

I saw that the Hughes cams had a much higher lift compared to the Melling. This build is to see what the factory supplied to their customers for a heavy sport car with a/c and the manual transmission.

The Edelbrock heads would wake up the sleeping giant.

Thanks, @451Mopar, for your deep dive into this part of getting the brute back to the asphalt.

 

[451Mopar]

As a hobby, I find this interesting. I am using the 516 head flow numbers from Stan Weisses chart, but there is only one entry for a stock 516 head, so I'm curious how accurate the flow data is. I actually have a set of rebuilt stock 516 heads that I am now thinking about having them flowed to see what numbers they produce?
Also, I need to look at the narrow LSA cams a bit more. The simulator installed the cams advanced quite a bit as I was asking for max torque.
I'm curious if when they are installed straight up, or even slightly retarded that they produce more power at the higher RPMs without dropping off as fast?
I was thinking of putting the 516 heads on a 383 to increase the compression ratio, but looks like they could use some port work and likely larger exhaust valves.