Need some help with this cam selection

[Broncojunkie]

I'm planning a 351w swap for my 79 cobra. Not for any other reason other than the fact that I have a couple motors lying around. I ended up trading around for another freshly machined block and a new 408w rotating assembly. On another trade, I ended up with a new cam (retrofit hydraulic roller) and I would like to be able to use it on this build. I am doing a roller conversion, as the block is an early non-roller. Other than a couple 302's and a recent 331 stroker, I don't have much experience in choosing cams. Can any of you take a look at these cam specs and tell me what kind of performance and street manners I can expect? It's going to be a street car with occasional 1/8 mile track run.

[Zap's 85 GT]

That's going to be pretty rowdy. Even my custom HR cam for my 408 and AFR 205's only has 231/239 duration numbers and it's at the limit of what I'd want to drive on the street. It will probably have less than 7-8in of vacuum if power brakes are a concern.

[Hammer Down]

No expert here but I think you could go more 'radical'. Have you considered a custom cam. I
dont have one but the guys that do RAVE about them.

[xctasy]

There are no wrong cam choices, only wrong engine combinations. You'll pay more on fitting the Heads, intake, and gearing to match the XR 288 RF HR -10.

Its effectiveness depends on heads, intake and gearing.

Buying over the counter "Comp Cams XFI 5.0 Stroker hydraulic roller camshaft" or "Crane 2031" cams are specfic to purpose.

PM EthylCat, and tell him I sent you. I really hope he is okay, he has given a boat load of counsel and help, and he has all the info to back up what a combination should make. He can do the horsetrade and comparisons.

Small Blocks don't have a lot of piston area, so the bigger XR 288 RF HR -10 in 351 w loose as much power in the usable 2700 to 3800 rpm rev range as they can gain in the 3800 to 6000 rpm range. This all depends on what you are using it for.

Geared right, the loss in torque can be over come. Your using a C4 and I guess you hoping to get EC's heads

The way to get something to work is to find the flow figures on the cylinder head, and details on the intake, and then design the cam to suit the gearing, horsepower and planned rev range.

Fords 351w stroked out with great heads love long duration cams in the 290 to 310 degree zone, but its the 50 thou figures and lift profile that engine builders focus on, and the best cost saving is best custom cam you cannot afford. The cam is the heartbeat.

[Walking-Tall]

Should be comparatively tame with 408 cubes. Conservatively assuming a number of things (10.5:1 CR & 91 octane, ported factory type iron heads, RPM or Stealth type hi rise dual plane, 750cfm carburetor, and 1-3/4" long tubes and full exhaust), it ought to churn out nearly 500ft-lbs @ 4500rpm with a nice fat torque curve (averaging 350+ ft-lbs, simulating from 500-7000rpm (lifter "pump up" past 6500rpm)) with greater than 300ft-lbs from 1500-6000rpm, and nearing 300ft-lbs right off idle, & about 425hp @ 5000rpm, and generate about 14"Hg vacuum @ 1500rpm, so a bit less at idle...

Upping to an 850cfm carburetor results in... 500+ft-lbs @ 4500rpm, averaging 355+ ft-lbs and nearing 300ft-lbs right off idle, & about 436hp @ 5000rpm...

[Broncojunkie]

I have 3.55, 3.73, and 4.10 gears. I also have dual and single plane intakes, a selection of carbs from 650 to 850 (all Holley) and haven't purchased heads yet...so I'm open to that. I'm perfectly fine with "rowdy" as far as the cam is concerned. I'm not really building this as a "purpose" car. Not a drag car, not a cruiser. Just something to take to the local cruise-ins and occasionally play around on the 1/8 mile track. Do you guys think this will work ok, considering I still have to purchase heads and valvetrain components? I forgot to add that I have a freshly built c4 (built to hold quite a bit of power). I also haven't chosen a torque converter yet and may need some input on that as well.

[Walking-Tall]

... and with a single plane and 850cfm carburetor: 520+ft-lbs @ 4500rpm, averaging 375+ ft-lbs, 300ft-lbs right off idle, & about 466hp @ 5000rpm.

Better than the assumed heads (ported early Windsor with 1.94"/1.60" valves) just increases these numbers everywhere...

[Broncojunkie]

That's the info I was looking for, guys! Thanks!

Any thoughts on stall speed to keep it street friendly, while still giving me a good launch every now and then?

[Walking-Tall]

Given some more assumptions (street tires 26-28" tall, that a $hitload of ideal "stall" does nothing but spin 'em to oblivion, without optimizing the pinion angle and some increased front-to-rear weight transfer and traction-enhancing science), and shifting at about 6000rpm, it's not likely you'd be shifting to 3rd gear crossing the 1/8 mile line, so 4.10's with your C4 to the top of 2nd gear should tear up the 1/8 mile pretty good. Highway cruise in Drive of 60mph would run about 3000rpm with 28" rear tires, or about 3200rpm with 26" rear tires, and IMHO a fine situation for a powerful engine to loaf along not breaking a sweat at all (minimal load, for sure still running off of the idle transition circuit, not yet the main (jets) circuit), needing very little fuel to do so. It's up to you, slicks and such, sure, "stall" 'er up near the torque peak... but personally I wouldn't bother with more "stall" than "stock" with street tires, especially with what should be a get 'er movin' in a hurry respectable amount of torque right off idle. More real world experienced folks will no doubt chime in

[Broncojunkie]

I have too many parts lying around. I've been planning on listing some on here and probably will do so this week! But I do have an 1,800 rpm stall converter. Again, I ended up with it in a lot iirc. 1,800 seems too low to me, when I have buddies running 3,000 plus on the street. But it is brand new and would save me some money for the rest of the build, if it's feasible to use.

[erratic50]

Why not build their "killer combination"
https://youtu.be/p1wU_8-JM

Most expensive part will be buying a transmission that will put up with the output!

[Broncojunkie]

Erratic, that video was crazy! So many unanswered questions, though. I wish they would have continued that experiment and tested the same heads with a big cam.

[erratic50]

To some extent I agree, but with the peak power and average torque of the little cam it leaves me asking myself if I think it matters...... It proves again what we've all heard for years - with cams and intake runner size on street motors frequently less is more.

I'd drive a fox with that 408 build in it! Would be a blast.

[xctasy]

Got any kb333-030 pistons?

It has been over 3 years. The Daddywagon is still not done. But out of the blue on impulse alone I ordered a set of kb333-030 pistons. These are the required pistons for a long rod 351w build. Maybe they don't really exist and will never arrive! I chose cnc motorsports over summit for the pistons based on price alone. Haha!

Those would also work with a 4.100" stroke crank and a 6.300" long sbc rod! 418 cubic inches and 12:1 compression @ 64cc. A 70cc chamber would make it livable I think at 11.15:1 compression.

Kidding (not really)

Enjoy your build!

Track down EC. Cam selection deals with peak power and torque curves for a given combination.

What the USA does best is costom cam grinds from known master cam profiles. If you want to do it the other way, then your variables are heads, manifold, exhaust headers, carb. If your going EFi, then you have to decide on what kind of system you can afford. Independent runner, or single plane 4-bbl or dual quad 4-bbl based. All of it then requires a specfic cam.

If your stuck with a given cam, and have to use what you have on your operating table, then you need a Performance Consulatant to help you because your choices are migrated to only heads, intake, induction and exhaust. And compression ratio for the fuel your gonna use. If your saddling all that with a stock Duraspark, then you migh miss the value of a lost spark, EDIS or TFi ignition, which give proven improvments in reliablity and tune, but might not help peak power.

I'd personally go to Speed Density Megasquirt or Lightening EFi with a hand gasflowed Triflow intake if your going to try making the 288 cam work. Mapping an engine takes time and effort, but Ford opted out on continued work on the Killer 351W combos when the 351W was killed off in 1997. Thankfully, Ford Australia kept on with intake design, and the result was the little 4" stock bore version of everymans 347





This was combined with a 4.6 Liter DOHC 80 mm MAF, with an EECV computer, and it was able to run up to 425 hp net, 90 hp more than its stock 5.6 liter stroker 5.0 figure.

The tall deck 351w and 408 combo allows a better than T3 Tickford intake, and the US has whatever you need to make your combo work.

You need to make a Stroker 351W list of parts that you have, and then figure out what to do.


This is what our Australasian magazines do all the time. Kevin Bartlett and Bob Kotmel used to spend all the time responding to Ford or GM owners who had heaps of V8 parts, and wanted to come up with a valid engine combination to suit. This is what performance is all about, building what you have.

The target intake exhaust cc is then basd on what intake runner manifold you have. Steve's program does a three way Flow Net estimation, and targets the air speeds that give the right torque with the right cam at maximum piston speed. If its a 4-bbl carb, you then have to define the right intake to suit the right carb sizes. Ita not all CFM, its about cross sectional area and length of the tract to the intake valve. The programs give you clues as to what works on a dyno.

Erratic, that video was crazy! So many unanswered questions, though. I wish they would have continued that experiment and tested the same heads with a big cam.

That's not the purpose of dyno testing.

This is why Chevy in the LS engines have copied the Windsor 351 porting, firing order and reverted back to non canted valve heads like the "Windies" have always run.


Dyno Testing is always one item at a time, but engine combos are always five items tested at a time. Questions never get answered except by packages evalutated on computer, then tested in practice.

Questions like....

21 Dec 2017
How the hell is a 400+ inch small block supposed to show the downfall of too large of a cylinder head? 220 is a perfect head for this engine, the weird results were because of the tiny camshaft. This test should have been done on a 302 with the sameish cam. It would have been fairly obvious there..

and

21 Dec 2017
i would have put a BIGGER CAM in it ? & do it over again

These are all out of scope from a quickie dyno test. Testing begats more testing.


Its not that no one has learned from the 1969-1970 TRANSAM Boss 302 and every production race endurance Falcon with the 351C 4V and Boss 351 style cylinder head's.

The low speed and transitional torque was why race teams epoxy mortered down the wild 4V Cleveland cylinder heads...to find the smallest cylinder head CC to make peak power, and improve the acceleration out of corners. Aussie call it a Stuffed Head. And why ohers high ported the exhaust, to balance air flow in and out. Intake and exhaust runner CFM is what CHI, John Kaase and his cohorts do all day when making 410 EMS engines. What a 260 cc 4V 351C head intake and 90 cc exhaust Cleveland head does is make 326 degree at lash cams with 800 lift rev to 9000 rpm without hurting the power curve.

[xctasy]

The reson I say all this is because right out of the box, performance parts that look the same and should work, don't work as well as some other factory parts.

Steve again set me straight

......



04 suffix lower intake for 351/5.8 Windsor, 09 suffix for the whole kit


Each has a different runner arrangement by simple geometric needs.......You can "cut and shut" the 04/09 351w intake to suit a 302c/351c deck with reasonable ease if its downgraded to the Windsor style TFS heads.......

Also that Box R disappointed me.

It flows less than a prepped Systemax intake.

It looks great until you look at the true flow path. It can be fixed though with some work.

[xctasy]

Steven and I discussed a Stroker 331 engine.

As an adjunct to that, we discussed intake manifolds.

The point was that the actual detial on the Box 3R is wrong, as it has no radius on the intake runners.

Rover with the Group A 3500 Vitesse and Holden with the 1988 Walkinshaw Group A Holdens found EFI with bell mouth intake runner EFi made heaps of power. The USA designers at Trickflow made a great inital attempt, but the guys who really know, just spend a few hours reprofiling the intake lower, and it then goes wild.


Link below is for the 80 mm MAF, 82 mm throttle body intake

http://www.summitracing.com/int/part...1008/overview/


Its similar to the factory 2002 5.6 liter 342 stroker intake manifold here,













and the top end specs are okay for well over 6000 grand with the 3.4" crank if the block is strong enough (the stock one isn't good past 6900 withthe roller rockers, and 7000 with the webbing), and 8000 with the 3" crank, or 335 hp net minimum in each case. .

[Walking-Tall]

I think the point has been overshot somewhat, unless of course the point is spending other peoples' money, lol... which in this department, all too often that seems to be the point... OP owns a 408 rotating assembly, wants to or is retrofitting the block for the roller cam he already owns and is interested in it's performance potential and what it's manners might be like in the combination, as well as owns dual and single plane carburetor intakes and has a selection of Holley 4-barrel carburetors on hand, wants to run the streets and cruise to the local flapjack or burger joint and occasionally run the 1/8 mile. If anything, this thread certainly looks like an inquisition and being in the market for what cylinder heads to put on top of it. The cubic inches themselves are going to nicely quell any loss of bottom end worries, and regardless of dual or single plane intake (OP, seriously consider using the 850cfm on this. That will maximize peaks AND averages with unhindered airflow, and any size Holley on any mild-to-wild engine/combination can also be dialed in for surprising fuel efficiency) or which cylinder heads end up on top of it, the range of rear axle gearing of 3.55, 3.73, and 4.10 that the OP also already owns, coupled with the C4 (with increased "stall" or without), should make for a pavement RIPPING holy street terror that quite likely will hit triple digits in the 1/8 mile too.

[Broncojunkie]

Most of the time, when guys start planning 408w builds, it's in an attempt to squeeze the most power out of it. While that is certainly an awesome plan, my situation is a little different. This will be about as close as you will ever see to a "budget 408w" build. I had originally planned on finding a good gt40 5.0 to drop down it it with cam and intake/carb. While that would have been the easiest and cheapest route, this stroker stuff just kinda fell into my lap, so I decided to go for it. I have another build in the works right now...a 351C 4v with a fitech efi setup. It may very well get a stroker kit and run high compression. So this windsor build, although it may very well end up being a powerhouse, is more focused on using what I have lying around. Of course, I can't promise that it won't eventually turn into a racecar lol

[mmb617]

I don't see any reason that cam would be too much for street use. I know there are a ton of factors in play to determine that but just looking at the cam my 408 runs one that's very similar. Same lobe separation, almost the same lift (.560 intake, .576 exhaust), and mine has just a little more duration (242 intake, 252 exhaust @ .050). I run it on the street with no problems at all. Well except it doesn't have quite as much vacuum at idle as I'd like for the power brakes but I intend to change them to manual one of these days. It will idle down around 850 and is very lumpy.

Even with the Vic Jr single plane intake it has plenty of torque down low, strokers tend to be torque monsters. I could get the front wheels off the ground launching at around 3k when racing. Around town I never notice any lack of low end torque.

I fully understand using parts you have on hand as I never have much money for parts myself. The only thing I'd wonder about is the fact that from what I'm reading that is a reduced base circle cam and I know a lot of people think those are a bad idea. I don't think there would be a problem with it in street use but I would be leery of racing with it.

[xctasy]

Then go for it! Are you using linked bar roller lifters?

The cam might not work well with the factory stock pressed tin retainer, but it doesn't have too much lift.

Broncojunkie, this is reverse engineering at its best!


and

I think the point has been overshot somewhat, unless of course the point is spending other peoples' money, lol... which in this department, all too often that seems to be the point... OP owns a 408 rotating assembly, wants to or is retrofitting the block for the roller cam he already owns and is interested in it's performance potential and what it's manners might be like in the combination, as well as owns dual and single plane carburetor intakes and has a selection of Holley 4-barrel carburetors on hand, wants to run the streets and cruise to the local flapjack or burger joint and occasionally run the 1/8 mile. If anything, this thread certainly looks like an inquisition and being in the market for what cylinder heads to put on top of it. The cubic inches themselves are going to nicely quell any loss of bottom end worries, and regardless of dual or single plane intake (OP, seriously consider using the 850cfm on this. That will maximize peaks AND averages with unhindered airflow, and any size Holley on any mild-to-wild engine/combination can also be dialed in for surprising fuel efficiency) or which cylinder heads end up on top of it, the range of rear axle gearing of 3.55, 3.73, and 4.10 that the OP also already owns, coupled with the C4 (with increased "stall" or without), should make for a pavement RIPPING holy street terror that quite likely will hit triple digits in the 1/8 mile too.

Perfect post dude.

The ancient Holley 850 is the 4-bbl dual use carb. Past 350/351/352/357, its the go to carb.

I've only used 780 cfm choke removed Holley 3310's on my first engine, the 351C 2V, and my second, an 010 350 with 400 heads and it too was about 325 rwhp, but automatic.

The other carbs just don't do it for bigger engines. Only issue I ever had was what you do best, phasing in the vac scecondary. I've never liked Vac Secs, I'd prefer to go mec sec Rochester Spread Bore on everything based on what the GM guys learned from Carter's on early Small Blocks.

My first proper performance engine which I helped with was with a guy who is now Fulton Hogans regional manager in Wellington, a great car nut who took me for one intoxicating 330 foot ride along his back street by the Catholic Church. I became a beliver that night. In Cleveland 351's with 780 cfm 4-bbls.

For his 375 hp Cleveland 351c 2V. The lesson for us was "build the best engine you can't afford, and that means make sure the engine block is the best money can buy so it always has residual value". If it doesn't, and you've won it by great wheels and deals, then you'll be able to replace it if you have to by the same native smarts and cunning you've already exhibited.

Nice.
The 4V heads really will like the lift. The 351C with 4V heads engine is an animal. Your choice of cast pistons, if they pass the die penetrate NDT and Zyglo test, will ensure the bores are looked after. I've seen a lot of engines lost to forged pistons. Blairs 1971 XY Falcon got an XE 192540 and we sadly, by accident, destroyed it due to piston clearances. It was a vigin bore, ex XE Fairmont engine. Nascar blocks came out in some pretty ordinary F100, Broncos, LTD's, Fairlanes, and Fairmont Ghia 4.9 squad cars

The engine had to get sold off, it was worth 5000 dollars NZ, and it got overbored 60 thou, and used in one of Roy McDonalds race cars. We replaced the scored NASCAR block with a D2 AE CA engine, and Blair used it for another 10 years untill it was stolen from the mine a Waihi.

If your an EFi guy, go talk with Zap's 85 GT on the Fitech.

I have a GoStreet kit on my F-100. I like it. It's an investment as it's tough to beat a well tuned Holley. I cruise and tow with my truck. Tuning the carb to work with the constantly changing fuel formulations, seasonal weather and heavy towing loads was a PITA with the carb. If I had a car, I'd just put a custom Pro Systems carb on it. Will save you about $600-$700 over the price of the cheapest kit and fuel command center. Might even make more power too.

The main issues I see if from people trying to save a few dollars from the EFI swap is by trying to engineer their own fuel system. They run into a myriad of tuning and nickle+dime issues that is easy to avoid if you just buy the fuel commander kit.

He loves it, and doesn't really like Holley EFi much because of its history with trying to buy out Fitech.

I like MS2 V3 because its almost an EECIV, but its 100% adjustable, can use a 4-bbl single plan if you weld in bungs, and its underhood with an Edelbrock elbow adaptor. MegaSquirt is not as nastiliy mannered as the eeekkk Four can be, and there is support for it from some very clever people.

Carbs? They work just fine if you are prepared to get into them.

[Broncojunkie]

Xcstacy,
If it wasn't for cost, I would just assume use the stand-alone kits on everything...even my 88gt, which I converted to mass air. Just the fact that they constantly monitor/adjust fuel, air, and temp makes it worthwhile. But I happen to have carbs lying around. A quick rebuild/cleaning and I'm in business! With the efi kits, I'm looking at closer to a grand and they'd be going in cars I'm only driving occasionally during the spring and summer. I do think I need to talk to Zap's 85 GT on the Fitech, though. The unit I'm getting is a 1,200 hp kit, iirc. I'm getting it from a good friend who had it installed on a project that he ended up ditching.

I also completely agree with you about reverse engineering, lol! I very well may ditch this cam and buy another one that suits this build better. That's still to be determined. If nothing else, I can sell this one off and use it towards a custom grind!

[Broncojunkie]

mmb617,
The small circle based cam is another issue I'm trying to learn about. I have read multiple people talking about how it's not a good idea...but I'm not really sure why or even what the difference is between a regular roller cam. It just so happens that I have a new set of link-bar lifters, which if I'm not mistaken, can be used with a regular roller cam. However, they are an off-brand (maybe from ebay?) and I keep reading that some of the big name brand link bar lifters are notorious for failing.

Any input on roller conversions? Just how bad of an idea is a small circle base roller cam and why?

[mmb617]

The reduced base circle cams use a smaller diameter core which makes them more prone to flexing and breakage. That's why I said I'd be reluctant to subject one to the stress of racing although it would probably not be a factor in pure street use. I'm not an expert on them but I had read up on them extensively when I was building my engine, and everything I read advised against their use for racing.

I ended up using a roller block as the only alternative beside the rbc cam would have been link bar lifters, and a name brand set of those was about $500 at the time. I don't know what they go for now and also don't know what brands are considered "good".

I do know a lot of guys are running link bar lifters in some high horsepower applications so they can definitely be a way to go. If I were in your shoes I'd probably run the link bar lifters you have with a regular cam before I'd use the rbc cam. Worst case, a lifter failure would most likely result in less catastrophic damage than having a cam break. But that's just my opinion and I don't claim to be an expert.

[droopie85gt]

I don't see any reason that cam would be too much for street use. I know there are a ton of factors in play to determine that but just looking at the cam my 408 runs one that's very similar. Same lobe separation, almost the same lift (.560 intake, .576 exhaust), and mine has just a little more duration (242 intake, 252 exhaust @ .050). I run it on the street with no problems at all. Well except it doesn't have quite as much vacuum at idle as I'd like for the power brakes but I intend to change them to manual one of these days. It will idle down around 850 and is very lumpy.

Even with the Vic Jr single plane intake it has plenty of torque down low, strokers tend to be torque monsters. I could get the front wheels off the ground launching at around 3k when racing. Around town I never notice any lack of low end torque.

I fully understand using parts you have on hand as I never have much money for parts myself. The only thing I'd wonder about is the fact that from what I'm reading that is a reduced base circle cam and I know a lot of people think those are a bad idea. I don't think there would be a problem with it in street use but I would be leery of racing with it.

Not to derail the OP thread, but what vacuum do you see on the street? I am going with a 351 swap. I currently run A TFS Stage 2 cam in my 302 and bought a Comp XE282 to put in the 351. It's got some big duration numbers 232/240 but it's on a 112 lsa which I think, should help make a little more vacuum with less overlap.

To the OP I wouldn't worry too much about the small base circle cam, UNLESS you want or need to get RPM out of it to race or just to get to the meat of the power band. A dual plane is almost always a better choice for a street car. The single plane is going to kill off a ton of torque below 5000 and you might not be able or want to rpm the engine enough to make it up on the top end.

There's another one of those engine masters videos where they are going to run a blower on a SBC with cast pistons and put a single plane on it to dyno it N/A and they just about fall out on the floor at how BAD the torque is N/A with the single plane.

For how goofy Frieburger and Dulcich are and if you can get over the non stop AmsOil commercial, they do some pretty good tests. They aren't always perfect, like when they did a flat tappet vs. roller test but the roller cam had more lift. But they do get some hard scientific numbers on various combos.

[Ethyl Cat]

Man, Xctasy didnt mean to get you worked up! Seriously though, thanks for voicing concern for my well being.

Big life changes, lap top crashes and several other things have prevented me from a lot of things lately and sadly FEP was low on the priority list. I still owe a couple people on here some things and I will get to them guys if you are reading this.

OP that cam is not going to be your issue if you put stock type heads on it. My heads that I had for sale on here for example would not make it past 5000 rpm due to inlet restrictions not camshaft. Piston demand would create such fast airspeeds (roughly 600fps at 6000rpm. 550fps is the considered max and 524fps is what I try to use for most street MCSA calculations) it would choke the port, regardless of lift.

I would guess that those heads and that cam would make 350hp or so and 450+lb/ft on a 408 with 5000rpm being the peak. Not sure what piston is in the kit but it might be hard to keep compression down with a 4" stroke and 58cc chamber.

As said in other posts, high cylinder pressures at low speeds is not always a great thing if you are on pump gas.

Big cid needs big intake valves. Another post talked about AFR 205 heads. That is a 2.08 intake valve and a .315" stem. His cam was ground accordingly as better heads need less cam. I think I have stated that many many times on here. I would bet that his engine still pulls real good to 6500rpm.
A 2.08 intake valve with a 90% throat is 500fps at 6000 rpm on a 408. 17% slower air speed for 17% more area.

Of coarse valve size is only part of the equation, but you get the picture.

On small base circle cams, a small base circle SBF cam is nearly the same size as a standard SBC cam. I would not worry about any ill effects due to that. The base circle is reduced to compensate for the much taller roller lifter used with the spider and dogbones. A linkbar lifter would not be that tall and would not require the small base.

I recommend Morel lifters for everything.

BroncoJunkie I will post a couple pics of what I do shortly. I think you might like them