Cam Size At The Edge of Loping?

[Dot Heton]

I'm ready to pick a solid lifter cam for the 390 in my '66 F100. The engine will be decked, line bored, bored, heads shaved to guarantee flatness. I'm shooting for a nice tight quench with h304p pistons ( or other recommendations) it should have about 9.5 or a little less compression.  C8ae-h heads with minimal exhaust port cleanup. Currently has an NP435 and 3.50 years. I'll be going to a C6 when the engine gets reinstalled.

I usually just cruise around and maybe spin the tires once in a while. What solid cam would fit the bill without much lope.  Ken at Oregon cams suggested a 427 grind, or something similar to comps 270s but on a wider lobe separation. 

[ScotiaFE]

The 270S would be a good fit for your package.
You could open it to 112*, but it will pull strong even at 110*.
With your plan you will have no problem smoking the hides at will. Have fun.

[cjshaker]

Something in the mid 220's @ .050 on about a 112 LSA works very nicely in a 390, especially for a truck. Not enough to lope, but doesn't idle like a Honda Civic either. It'll have a good broad torque range. Just my preference, but I tend to shy away from Comp on mild street builds because of their aggressive lobe profiles. They give you more 'area under the curve', but at the expense of being harder on the valvetrain, especially the lobes and lifters.

[ScotiaFE]

You make a good point Doug, but as a good daily driver it would be a better choice.
As a weekend toy that see's limited use, a cam with a bit more steam will only make the weekend
more fun. And he does want to do burnout's.

[My427stang]

I'd look at L2291 pistons and potentially a slight deck cut to close up quench, the H304Ps are not only deeper in the hole by about .020, and run lower compression both due to dish design and compression height, also despite hypers being adequate, I much prefer a forged slug. The 2291s also fit nice and tight and run very quiet.  You may spend an additional 100-125 bucks, but the octane tolerance of the tighter quench will make it worth it, along with the torque associated with the compression (and it better matches the cam characteristics you are looking for)

As far as camshaft, I have very good luck with a 270H in a 4x4 390 truck.  Sounded strong and pulled well down low even with a Street Dominator in a 4x4 truck with 3.50s and 33 inch tall tires.

The 270S would likely make even more low end, but the simplicity of hydraulic lifters and stock non adjustables is pretty nice.

FWIW, I also recently used a Summit cam for a build for a 4.11 geared truck with 38s and ported D2s, the truck isn't running yet, but it is 276 adv, 219 .050, 110 LSA on 106, lift .500-ish if I remember right, also hydraulic.  Should be a good fit too and have a little chop to it at idle.  Price is nice as well

BTW, Dougs recommendation works out to a 270S on a 112 spread, vice 110, and then you can pick ICL based on compression, but my guess would still be that it would like 106, it would also be very nice

[Dot Heton]

I measured one piston at .012 down and one on the other side at .026 down. I hope it squares up. The funny part is that it appears to have never been apart before. The previous owner says it came out of a '69 wagon and ran very strong. Thanks for the tip on the L2291.

I'm sending the cam to get reground to the 270s lobe on 112. It should be exactly what I'm looking for.

[cjshaker]

Rather than just hope it squares up, I'd make sure the machine shop MADE it square. But before they just go cutting, they should verify deck height on both sides and conclude for sure why they are different, even mock it up and double check if required. Did you only check one piston on each side? It would have been wise to check from front to back also. If your measurements are accurate, then it's probably the block, and a bigger cut on one side would be required. Getting that quench right, as Ross suggested, will only help the engine perform right and not have issues. If the machine shop can't perform these simple operations, then I'd consider finding one that can, if at all possible.

[Dot Heton]

There's no problems with the shop, I had my first engine built by them in the eighty's for circle track. But it's great that I found out about the L2291 piston and confirmed that the cam would work.

[My427stang]

So you can calculate where you want it

1/2 of stroke plus rod length plus compression height - with a L2291 and a 10.160 deck you are .004 down, add a 1020 Felpro gasket and you are sitting pretty

[Heo]

I just had a block paralell decked for L2291s at 10.155 and it
is level with the block

[Dot Heton]

The 270s is in the Magnum range so I'm guessing it doesn't have such aggressive lobes like the Extreme Energy series? Or am i wrong? I want something easy on the valve train.

Also, Ken didn't mention anything about the ICL. Should I tell him I want it at 106? Would I have it assembled straight up or?

[My427stang]

The 270S is a good street cam, it doesn't beat anything up

As far as ICL, without dyno testing it's really technique, math, experience, etc.  If you are runnling L2291s, 10.160 deck, a 71cc head, and 1020 gasket, I'd index that at 106, and would even go as late as 108, in a heavy-ish truck

If you buy parts that drive your compression up, I'd lean toward 108, if you drive parts that drive it down, you can go 106, or even earlier depending on how it comes together.  In the end though, 106 is pretty safe unless your chambers measure smaller than 71

[HolmanMoodyStroppeGang]

Howdy

You can take the rod and piston that measured 12 down, and install it in the number 1, then 4, then 5, then 8 cylinder and use it as a height gage. If it is 12 plus or minus 'x', you have a clue as to how square the block really is. Write it down, then have the machine shop use this data for guidance.  I mike the dimension in all 4 corners with a FE tool and long calipers. I have a depth gage too.  a real good FE machine shop can blueprint your compression height too. An average machine shop won't.

Then you know, if the deck is the issue, or the other assembly maybe out of tolerance for sure.

Now here is the wrinkle.  If a crank grinder was sloppy, they may have turned the crank throws wrong. You can catch this but please note, if the crank is 10 or 20 under on the rod journals, it may no longer have the same exact stroke on each pair of rods. Seen that on a tear down measuring check.  So you will get clues and can back check this too, before re machining it all.

If a crank is centered fast and dirty as the rod jounals get ground, they can be off 2,3,4 thousandths too.   Check it out?   using one rod and piston as a gage, sets the stage to check, then eye the true stroke.

I always re install any crank after VELASCO, BRYANT, CROWER, SCAT or SHAVERS stroke corrects it exactly, and then indexes it to be exactly 90 degrees apart on the throws. If you want free power, look in to this too.   An we give the grinder the dimesion we need, after sizing the rods and mains, and measuring the bearings to the 0001 (tenth). This was, you set the mains and rods where you like them.

On the cam, FORD raced so many trucks, and we won so many races and championships with F250s, off road,,,,I would look back, then forward for fun.   I would go to our old cam grinders for some nice cams too. We won a lot with FORD cams, and the below. Super reliable grinds too

An ISKY 262 Mega Hydraulic is on 108 lobe centers, and has a nice lope, and a bunch of grunt down stairs for a 390 with ported heads, and a Street master. Pull hard with headers, ported heads, lower gears, and a 780 or 750 DP Holly.  It is 488 lift, 256/262 duration, 202/208 ex duration at 050. Also the 270 HL    510 510 lift, I like this extra lift here, over a 270 comp, 270/270....216 /216 at 050 lift.   You have more choices there too. ISKY has never used the less durable core made in INDIA. Be careful there. If any cam company strongly suggests that you nitride a cam, look out. The core is not american probably

We ran ENGLES too, they make wonderful FE cams, and we won a lot with CROWER cams, like the Desert Dualer series and similar grinds to a 270 comp. The 270 Comp cam is a nice choice but don't forget many companies have old grinds. LUNATI is well known for many great FE cams too. CROWER has excellent FE cams in the 270 range and they were a vendor to FORD back then too.  Full sponsor to Holman Moody Stroppe and key to many wins for Parnelli Jones and Walker Evans.   ENGLE helped us win for FORD too.

On a Street truck, with manifolds, and the specs you chose, we also really liked the FORD, 6250 B cam. We called this the Cobra Jet B cam. Real nice piece for many FE's. It sounds true Ford to us too. Has a Detroit EEE lope. Wide lobe centers and excellent street manners, no power brake issues, etc.

Ford listed the CJ cam at 270°/290° 'gross' duration, lift as .481"/.490", and did not publish @ .050" specs. Crane & Lunati list their 'blueprint' cams for the 428CJ/390GT as having around 224°/232° @ .050", but the OEM cams really checked out around 209°-211°/219°-222°, depending on who was doing the measuring, and valve lift was more in the .475"/.486" range.

ISKY and LUNATI have a Blueprint series of the original FORD CJ cam that is a real nice 390-428 cam, with a mild lope, and it has the attitude that FORD engineered in for a heavy car on pump gas.  CRANE has some real nice FE cams no doubt and they provided FORD with special FE grinds decades before COMP was born. No knock on Scooter and his fine guys.

We honestly won a lot more with dual pattern FE cams since the stock exhaust port has some issues to work around in some cases.  We often opt for a grind, rarely a catalog cam, and I would check in to some dual pattern grinds too.  FORD spec'd a dual pattern cam for the CJ Hi Po cams for good reason for example

The tight quench tricks are always a very wise investment as descibed

The tight piston to wall, combined with a torque plate hone is also free horsepower and durability

Blueprint the oil pump, check the end play and maybe shim the relief valve, add 1/4 NPT pipe plugs in place of the press in plugs, maybe relieve the block around the intake valves, and line hone it if needed. Chase all of your threads with a tap, debur it all a bit, balance it nice and have fun !

We always clean the ports up at least to the level of pocket porting, and we have porters here, or if you are patient, and have a plan, you can smooth up each port around the bowl, do a little port matching, cc them, we always do that, and more.     Port them before you do the finish valve job or have one of our members do a basic street port job.  I have very good head guys if you want a referral.  I like to do it myself, for ever anyway, many here do it too. Ask around maybe.

Sounds like a fun build

Have a blast

[Heo]

Thats the way i do it.I take one rod and piston and use it to meassure
all four corners to have an idea how much out of square it is
And my last block had bigger differeces than you have
It was the factory machining. Right bank lower in the front
left bank higher in the front. They are not that precision machined
from the factory. And castiron can move around for a while after its cast
Big Ship engines is stored for up to eight years from casting to machining

[Dot Heton]

Great info. I'm only looking for the grin factor with this truck. I know from my personal history that I get tired of too much lope when I'm sitting in traffic and this eventually keeps me from taking the truck out as often as I'd like.

Im going with the 270 lobes at 112, I'm having my stock cam reground so the core should be good.