Small Block Cam Info - Magnum Head Swap

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SilverStubby

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Hey guys, I'm trying to make some budget power from the junkyard to make my $500 87 B150 van run a bit better. It's got the factory 2 barrel carb and single exhaust, so it'll be hard to make less power.

Motor: 318 (unknown year, unknown components, I assume factory 1970-80's, will dig into more, we knew it ran and it was sitting in the shop so we plugged it in.)

The plan now is to use some junk magnum heads from the yard (I know they're probably cracked but I don't care, my 96 magnum van ran great for 170k), install some GM springs and do some quick port cleaning. I'll be adding a 4 barrel carburetor, intake, possibly headers.

I plugged in some of the valve spring info I found online for the GM 3100 spring, thanks to Patrick at the Moparts forum.(new cheap magnum spring upgrade for moderate cams) I used a bind clearance of 0.09" which gave me a max lift of 0.485 with a 1.6 ratio rocker.

Valve Spring Info.PNG

Below is the cam info I worked out, the whiplash cam from hughes caught my eye but I had to work backwards from the specs they give and do some guessing to compare it to the other cams. The lift was too large.

Cam Info.PNG


I went way further into this than I should have but I wanted to make the info available if anyone ever wished to use it. Nothing has been purchased since I'm still confined to my house... hopefully be able to make it to the salvage yard soon. Also, debating to just use some 302 smog heads, better springs and a bigger cam. I liked the larger valve and smaller combustion chamber the magnum heads have... as well as the 1.6 ratio rockers.

Would like to also put in an OD trans from a 91 dodge and a posi rear end.

-John
 
Welcome! looking forward to your test results. I'd lean towards the magnum heads for pretty much the same reasons.
 
Thanks! I'm setting my expectations low so I'm not disappointed, it is such a dog right now.

Used this graph to compare the cam's once I picked a few that worked, it was pretty interesting to visually see the lobe separation, duration and when the valves open and close for the different grinds.
Camshaft Calculator & Valve Overlap Profiles | MGI SpeedWare

I've referenced a few builds online and some engine masters episodes to help my cam selection, these were much higher RPM engines than what I'll be building and flowed much better.
https://www.hotrod.com/articles/318-small-block-build/
318 Engine Build - A Parts Book 400HP 318 - Mopar Muscle Magazine - Hot Rod

Ep:53 (I had the same thought about selecting a cam based on the intake valve closing sooner to raise compression but they showed static compression doesn't matter near as much as air moving through the heads. I compared the cam used in that video to a few I was looking at for comparison, Comp Cams 21-600-5)
ENGINE MASTERS: Season 4, Episode 53 - The 440 You Can Afford | MotorTrend
Ep:58 (This is where they actually degree'd the cam in)
ENGINE MASTERS: Season 5, Episode 58 - Advances in Cam Timing | MotorTrend
 
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anyway to make that spreadsheet live?
The Hughes is quite a bit fatter lobe than most of the rest but i have no idea what it is at .006 if anyone has measured it post up- use only on stock low compression builds
The first Howard 710011-12 is a Street Farce 1 transplanted chevy cam
Howards 712221-08 is another optimized for the small .842 lifter and quite a bit different than the Street Force- You are not considering both of these for the same build are you?
The Lunati Voodoo -700 has good lift for that duration as does the 701 Looks like the only MOPAR optimized cams on your list
For Crane- Crane measures advertised duration differently than the rest of your list (?Hughes) so subtract 7 degrees from Crane's advertised when comparing
All the comp cams you listed have marketing names but until you get to 275 degrees comp is not competitive
 
Anyway to make that spreadsheet live?

I'm working on it now, trying to figure out a way to share it easily.

The Hughes is quite a bit fatter lobe than most of the rest but i have no idea what it is at .006 if anyone has measured it post up- use only on stock low compression builds

That's what the website states, I had to work backwards on these numbers so the Hughes is a rough guess.

The first Howard 710011-12 is a Street Farce 1 transplanted chevy cam
Howards 712221-08 is another optimized for the small .842 lifter and quite a bit different than the Street Force- You are not considering both of these for the same build are you?

I threw a bunch of random cam's in the power range from Summit I was looking for. Some have too much lift for my combo, some I didn't like at all but I went through the work of adding them so I left them.

The Lunati Voodoo -700 has good lift for that duration as does the 701 Looks like the only MOPAR optimized cams on your list

What do you mean optimized for Mopar, the larger lifter diameter I assume? I would like to take advantage of this but I don't necessarily understand how. The larger lifters allow for a more drastic ramp right? So a faster opening and closing to the valve? I do like the Lunati but it went over my max lift, the 700 is still on the table though.

For Crane- Crane measures advertised duration differently than the rest of your list (?Hughes) so subtract 7 degrees from Crane's advertised when comparing

I wasn't aware of this, where can I find his info? That would make sense because the graph online looked off on those cams, the curve was much steeper leading to the @ 0.05" lift number.

All the comp cams you listed have marketing names but until you get to 275 degrees comp is not competitive

What do you mean? 275 degrees of advertised duration? The long duration comp cams seemed like they all had too much lift for what I was going for.

If you have cams I should add let me know, no real science to how I put them on the list. Should probably remove the cams with too much lift.
 
Welcome! In a B series, I assume you want low end torque. The magnum heads will add torque/hp. HOWEVER, you'll need different push rods and the right length that oil through the lifters, which means lifters that oil through. Both are easy to get and not overly expensive.
 
318willrun, thanks for the info! I got some push rods picked out based on that!

I got the link to work and added some more cams. This time I threw in some Mopar cams that would work and I think I understand what Wymer was referencing. The mopar cams have a ton more duration than the other cams so I assume the lobe may be a bit "flatter" possibly?

upload_2020-4-17_20-0-20.png


Here's the link to the spreadsheet if anyone wants to play around with it. Definitely not claiming any of this info is 100% accurate, I make typos easy. Hopefully the link works for everyone.

 
Wyrmrider, I laid some mopar cam's into the graph and the difference was pretty drastic. Thanks for the schooling!

The graph for the Crane 15005 is below, the ramp from advertised to 0.050 is really shallow... fit for a small diameter lifter.
Crane.PNG


The Mopar purple shaft MOPP4452761AE is below, the points for the duration at 0.05 & advertised are much closer together.
Mopar 1.PNG


And the Hughes really shows off the drastic change with a higher lift, I got the advertised duration from using the averages from the Mopar cams vs. the average with for the ordinary small lifter grinds.
Hughes.PNG


I'm a visual learner so the graphs helped me wrap my head around it... more area under the graph the more air in and out!.
 
wrote this yesterday but it did not post
love those Jane Mansfield views really shows the differences
I think you may be off on yur hughes adv durations go to the howard catalog and find a 213 & whatever the ex lobe is @.050 and use those oo6 durations
nce exercise

The cam/lifter accelerations are the same on the chevy and mopar voodoos, the mopar voodoo operates on the larger lifter which does make the valve move faster
I just posted something yesterday on another thread, I'll see if I can find it.
So if you have a low compression 318 the short 200 degree voodoo- the first one on a 108 ICL is going to get your intake closed earlier than anything else on your list
if closer to (a real based on cc.d chambers) 9:1 you could use the second voodoo or the second Howard in the online catalog, the one with 15 in the comments column unless it has too much lift
The est of the cams on that list are optimized to separate you from your money
For an OD trans they start out on the 92 318 then the 93 360 Magnums through 95 for the 518 with THREE wire connector this is also called a RH trans not RE
easy to adapt as it is not computer controlled
 
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on your crane graphs remember to subtract 7 degrees
crane's advertised is at .oo4 wheras the others are at .oo6
I used to use 8 degrees but found on the Camcraft website a listing with both .004 &.006
btw camcraft learned from Harvey Crane not UDHarold
now for MP
MP uses a unique way of measureing duration
but it works out to close to .008 (also Engle and Racer Brown))
so for the MP cams I'd add 8 degrees to the advertised
These additions and subtractions are necessary for dynamic compression calcs too
 
another post i wrote earlier but for some reason did not post

The cam/lifter accelerations are the same on the chevy and mopar voodoos, the mopar voodoo operates on the larger lifter which does make the valve move faster
I just posted something yesterday on another thread, I'll see if I can find it.
So if you have a low compression 318 the short 200 degree voodoo- the first one on a 108 ICL is going to get your intake closed earlier than anything else on your list
if closer to (a real based on cc.d chambers) 9:1 you could use the second voodoo or the second Howard in the online catalog, the one with 15 in the comments column unless it has too much lift
The rest of the cams on that list are optimized to separate you from your money
FWIW the .006 to .050 can be around 46 degrees with both mopar solid and hr cams
remember that when looking at intensities that Crane uses .004 to .050 whereas the numbers from comp are .006 to .050

For an OD trans they start out on the 92 318 then the 93 360 Magnums through 95 for the 518 with THREE wire connector this is also called a RH trans not RE
easy to adapt as it is not computer controlled
 
"Hey guys, I'm trying to make some budget power from the junkyard to make my $500 87 B150 van run a bit better. It's got the factory 2 barrel carb and single exhaust, so it'll be hard to make less power."
Stick a 340 cam in it and see
 
Wyrmrider said:
"Hey guys, I'm trying to make some budget power from the junkyard to make my $500 87 B150 van run a bit better. It's got the factory 2 barrel carb and single exhaust, so it'll be hard to make less power."
Stick a 340 cam in it and see
Click to expand...
No matter how many times its said the stock 340 cam in a 318 sucks is BS. I have personally done it 3 times advancing it by 4 degrees and it works very good. Power
increased from bottom to top. Real cheap out is find a good used 340 cam w mating
lifters (old quality stuff) thin head gaskets, may get it going for 100 buck? I have also used high rate roller cams in 318 yeah they work a bit better. Its very easy to spend
other peoples money, you got a JY engine in a van... cheap out and have some fun.
 
I'm using this as a learning experience, planning on applying whatever I learn to the small block I'll build for my 67 barracuda (why I joined the A body forum and posted about a van motor).

I've definitely been looking at upping the static compression but getting a cam with an early intake valve closure, that's why I liked the comp with the 108 lobe separation. plugging in cam's to see if I can find something similar to the Huges but not quite as drastic.

I did subtract 7 numbers from the crane unit but I didn't look at the lift numbers, I'll have to do some more digging, I thought the specs in their catalog were based on 0.05" but I'll double-check. Thanks for the info on the trans, I was going to start looking into that tonight!
 
Wyrmrider

I've come to realize that I can't actually map the lobes out with the advertised, and 0.05" numbers since everyone's advertised is completely different. But I was curious if I could at least compare all the Comps since they should be apples to apples. If so the Comp 20-300-4 seems like it has a tight advertised to 0.05" duration delta but I can't tell what it does from there. I did look up the grind number and it came up with a bunch of Chevy stuff so there probably isn't any hope for that unit. I did look through Comps lobe catalog and their Chrysler cams that are optimized for the larger lifter all have too much lift for my application.

I know you mentioned Howards cams and Vodoo, the Vodoo part number 10200700, But I'd like to go with a cam with a tighter lobe centerline, at least a 110. I found the Howard "Aggressive" lobe profiles but I don't have any way of knowing what cam's have those profiles. Let me know if you have a way of telling without just getting the actual cam in hand.

I am going to Comp and Howard's tomorrow and see if they can give me more info. The catalogues have a lot better info than you can find on the product descriptions... too bad they don't have the lobe profiles tied back to the cams somehow or maybe I'm just missing it.
 
66jim written yesterday but did not post

you can discuss with AJ/FormS on the how's and why's 340 cams work or suck on low compression 318 (late 340, 360)
you advance the cam and your exhaust opens early and it's already opening early with the 114 LCA
what gears and converter with you 318s with 340 cam
it's about 279 @006- a 280 degree class cam

Stubby which comp? Mopar Cam- how many more degrees @.006 to equal at .200?
If you look at the thread "how much duration does it take or something like that I have not given the answer on how much more duration you need with a chevy lobe to match the .200 duration of the short Howard but Ill update that thread- but it's like 20 degrees
with your lift limitations I think the lunati @108 is your only choice- I think the howard gives too much lift but I'll check
ps the 340 cam even with 279 duration does not get the .200 duration of the 256 Howard- it leaves a lot of low end on the table with that long duration for a little lift and it leaves a lot of power on the table with the anemic .200 duration (.350 at the valve) even with low gears and you rev the snot out of it
 
Stubby

I've come to realize that I can't actually map the lobes out with the advertised,
I told you how to do it
most everyone is .006 except Crane, Cam Dynamics, Summit and the white Boxes at .004 and at these durations scratch all off your list
Then the MP, Engle and Racer Brown at .008 and Isky just add 8 degrees you will be close
As for comp there is absolutely nothing shorter than ,275 that you should be interested in. The Purple Plus 280 is the smallest in that line and the Nostalga Plus is a similar design but dumbed down to make mfg less expensive- you loose torque compared to other cams with similar advertised durations on the list I posted
you can get the details in the comp lobe catalog which btw is much better than most

"ut I'd like to go with a cam with a tighter lobe centerline, at least a110"
LCA should be a result not an input
where do you want your intake to close at .006, how much overlap @.006 etc
I forget is your lift limitation valve stem seals or springs. ??
The MP cams, Engle and others that may fit your lift range and still provide a big fat lobe, like a shorter purple plus
do not get caught up in the marketing "my dick is bigger than your dick" sindrome
you might check out the 904 lists at Bullet and Camcraft, Engle

Forget agressive lobe profiles, and I consider the Comp XE line borderline agressive . more agressive than the Hughes, Lunati but since it is working on the smaller lifter that's hidden
I'd work on engine sims first, cams can drive you nuts, get the compression and rev range nailed down and the list of good working cams will narrow
let us know what you find
 
and your lift limit is why? JBW Howard has a whole list of cams in their lobe catalog pick one with the max lift for you and tell us what it is
tooomuch lift?
EngleK52 Hyd 260 209 ,295 ,489 w 1.6 254@,008
Looks like you could use a "dwell" nose cam how much lobe lift can you take pretend you are a lift limited class
here's some from Bullet
D is dwell nose A is Asymmetrical S is symmetrical
.................... adv .050 .200 lobe lift
HC267/300 267 214 127 .3000 .000 CTA need to find some "lift rule" cams in your duration range 293 and up is not for you
HC293/303 293 248 165 .3030 .000 DTS

HC293/305 293 248 165 .3050 .000 DTS
HC296/305 296 250 163 .3050 .000 CTS
HC307/300 307 258 172 .3000 .000 DTA
HC303/308 303 258 175 .3080 .000 DTS
HC309/305 309 264 180 .3050 .000 DTS
HC309/308 309 264 180 .3080 .000 DTS
HC314/275 314 268 179 .2750 .000 DTS

I have no idea which might be intake and which ex lobes or which are for light and which are for heavy valve trains
so figure out what you really need and we can help find your special cam
 
Max lift with 1.6 is 0.485 because of the spring height in the first post. I think a dwell nose cam is what I was trying to find but I didn't know the name or how to actually find one. With such low lift, I'd like to take advantage of the flow just below ~0.500 for the factory mag head (221cfm int / 159cfm exh) and after you mentioned the 0.904 lifter advantage I figured there would be a cam out there that would have an accelerated ramp-up to a low lift, plateau around the .485 mark and then ramp back down. to close. That would give me a larger area under the curve but I didn't know if it was possible or not. My goal was to get as much air in and out of the chamber as reasonably possible, the cheapest way possible and see what happens.

That's also why I didn't think I could find the cam lobe profile just based on the advertised 0.05" and lift numbers because it wouldn't show the plateau. But if I had the 0.200 numbers I probably could get closer.

I really want to get that google sheets doc up so people can use it as well, that was my main reason for joining and posting was to get that usable and get it out there for people on the forum to use if needed.
 
ok
but get your duration/ rpm range/torque requirements first to limit your search
you could squeeze your spring down to .060 or change keepers/ retainers if that works mechanically clerance
would give you a lot more chices
as of right now the jones motorhome grind may be your best choice
check the lift
a lot of amc 1,6 rocker guys have written on this cam- me too even at 1.75
 
no problem
You should be able to make the Lunati 700 work Ive seen two versions one is 250-206 intake and the other is 253-208 intake
as far as I know (AFIK) it's the only shelf cam that comes close

you could have Lunati grind with the 700 intake and the 701 intake ground on the exhaust giving you 253-256 @.006


You could have Engle grind the K-52 (good lobe) on the intake and a slightly longer (depending on you head flow and exhaust) exhaust from their cam library to meet ex lift

This is the best combo that comes oh so close
Jones 256 202 120 .305 .461 50% fatter @.275 than DC 260 (269 @.006) .305 lobe is only .002 above your spec

H64307-66299 256/[email protected] 202/208 .307/299 .491/478 w/1.6 111 LCA IC 109 ex 114 you could have the LCA wherever so find another .007-010
you could also have Mike spec a different ex lobe to match your ex flow reuirements- actually it's better to let him pick the lobe once you nail down your needs

Crane also has some out of catalog lobes
Crane 2022880 252-4 202 113 0.299 H2 series .904 lifter ([email protected]) The 252-4 is my .006 estimate
but you can see that the Jones is considerably bigger at .200

The Engle and Jones are sort of Dwell cams big noses for great wear

here's a comment on the Jones cam above
"07-20 38 10 @.050 3 0verlap per Shawn Watson
IO same stock 401 IC 5 later stock ex opens and closes 4 degrees earlier than stock

Custom Mike Jones cam, 202 max area intake lobe Jones designed for Chrysler 440s.

More area under the curve than a longer-duration cam like a Comp 268, extremely fat at 250-275 lift, about 50% more than a Mopar Performance 260 cam.

Fast acting, but the nose is big and reduces wear
Longer duration style 208 (264) exhaust lobe for high-RPM power,
Over 400TQ from 3400 to 4600 and over 375TQ from 2800 to 5000 in AMC 360.
 
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