Cam lift

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v8ranger
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Re: Cam lift

Post by v8ranger »

I have a comp cam now. The duration @ .006 is, tappet lift Intake 281 exhaust 281
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
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cgrey8
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Re: Cam lift

Post by cgrey8 »

Interesting. What's the model number? Is it an XE series?

As for your off-the-seat duration, 281/281 isn't that bad. But it's still well within the "aggressive" range. The FMS E303 is 280/280 and is on the border of aggressive and mild. It's the .050" duration that is well within the aggressive range on your cam and could use some narrowing.

This is just my take on cams, but these duration values are what I consider as aggressive:
>280@.006" (Intake Valve)
>218@.050" (Intake Valve)
LSA <112

Mild/truck cams are cams in this range:
<265@.006" (Intake Valve)
<210@.050" (Intake Valve)
LSA >114


Anything in the middle is what I would call reasonable street performance. The cam I have is a Crane Powermax 2020 which is definitely a mild cam. Also note that the numbers are specific to the intake valve. Commonly you'll get cams where the exhaust valve is wider and that's OK, even preferable in some instances. If one lobe is ever wider duration than the other, it's almost always going to be the exhaust valve. I don't recall ever seeing it the other way, but I'm sure there's an example or two of that existing. And again, these are rules of thumb, not absolutes. And there's FAR FAR more that goes into proper cam selection than just targeting specific numbers. But when you don't have those details, you do the best you can and that's reverting back to rules of thumb.

Either the XE264HR12 or the XE270HR14 will serve you well. Both are great cams. I've never known anybody to own either of those and be disappointed. If you are worried about going too mild, go with the XE270HR14.
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Re: Cam lift

Post by v8ranger »

This is what is says, Grind # FW 281H-R10 Part # 35-440-8
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
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cgrey8
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Re: Cam lift

Post by cgrey8 »

Here's what I found on their website:
Comp 281HR-10
Looking at the specs from the Comp website, this is their near-clone of the FMS E303. Their comments clearly say this cam doesn't kick in until 3500RPMs which is about on par with what people say about the E303 that it doesn't begin to wake up until 2500. They confirm this by saying that this cam requires stall which means they don't recommend it to be used with stock torque converters. You'll get much better take-off performance with a high-stall aftermarket converter which will let the engine rev closer to the kick-in RPM before requiring that the wheels move.

I find it interesting that the website documents the cam's RPM range to 2000-5500. I think that might be someone's copy/paste mistake. I'd put the range of this cam closer to 2500-6500.

Bottom line, I think you'll notice an increase in low RPM performance and probably improved fuel economy replacing that cam with either of those two I mentioned.
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Re: Cam lift

Post by v8ranger »

Well I have the next 5 months to decide what I want to do. Truck is parked for the winter anyway. Sooner than I wanted it to be as the snow and salt haven't even hit the roads yet, but spun a rod bearing on number 6 that forced me to pull the motor last month. That's why I decided to just get an already rebuilt .40 over short block. Low end power has never been a problem. It just seems to fall off around 3000 to 3500rpm's.. Maybe its just me and I'm just getting to use to the power lol.. Maybe the .40 over will make some improvements on that...
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
User avatar
cgrey8
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Joined: Fri Dec 10, 2004 8:23 pm
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Re: Cam lift

Post by cgrey8 »

We talked a lot about cams here, and proper cam selection is important. But I feel a need to put into perspective cam selection relative to other things. The vast majority of an engine is in the heads. The absolute best bang-for-the-buck investment in an engine is upgrading the heads even if you do nothing else. You can put AFR or TW aftermarket heads on an otherwise stock engine and get impressive performance gains...more than you'll get by upgrading the cam, intake AND exhaust on stock or even stock ported heads. Now take that AFR-topped stock engine and upgrade the stock cam and the performance increase you'd get by upgrading the cam now is much greater than a cam upgrade on stock heads. OR take that engine and put a supercharger on it, and now you are talking about a really fun machine and all you've replaced are the heads and added a supercharger.

You might be thinking, but my heads aren't stock. I'm not saying your GT40 heads are stock, but they are closer, in airflow performance, to stock E7TE heads than they are to say a set of AFR165s or TFS TW 170s. Even if they were purchased as aftermarket, the casting design is stock production quality since they were stock equipment on a few different year vehicles (e.g. 93-95 Cobra & 96 Explorer). So if you are looking for a place to upgrade, the heads would be it for me.

I just didn't want the discussion to skew the importance of cam selection to being THE most important aspect of an engine build. It's important in that the wrong cam can cost you some performance you otherwise would've gotten. However a cam's ability to improve performance is limited by the other components on the engine. And with a booster, a cam has even less significance in improving performance, but too big of a cam can rob you of performance at the low end. There's plenty of people that advocate saving the money on a cam and running a stock cam with a supercharger and putting that budgeted cam-money somewhere else. I tend to agree with this philosophy because oversizing the cam can deflate the booster's performance. If the cam is too aggressive, it's quite possible you would've gotten better performance with the stock cam. That doesn't mean a properly sized upgrade cam won't give you some performance enhancement over the stock cam in a boosted application, but the amount more you gain is not worth the cost of the stick...IMO. But replacing an overly aggressive cam on a boosted engine with a milder cam is most definitely worth doing particularly if the engine's already going to be torn down.

I bring this up because if this is an option you want to consider, then consider a 93-95 Cobra cam. They can generally be gotten for fairly cheap either used or as replicas and are a better cam than the stock GT cam and FAR better than the F150/Explorer cam. As well, it would work GREAT with those 1.7RRs you already have. While I think you would have no problem with either of those cams I mentioned above, I can't honestly say that it's worth ~$350 to get a new Comp cam when you could get a stock cam OR a mild/moderate used cam for significantly cheaper and in your case would likely serve you just as well.

BTW, I would NEVER recommend someone run a used flat-tappet cam. I know people do. I just don't trust them. However roller cams are a different story. As long as the lobes & journals are in good condition (no pits or scars) and the dizzy gear teeth are good, there's no reason to value a new cam higher than a used cam. The cam I have in my 331 is a used cam I got from a guy in California. I couldn't be happier with it...and I couldn't beat the price (FREE).

Just something else for you to chew on...
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Re: Cam lift

Post by v8ranger »

I would love to put a new and better set of heads on it, but I can only afford one melt down at a time. I wasn't planning having to replace the whole motor. I did go looking on e-bay just for chits and giggles and came across these. http://www.ebay.com/itm/191362802868?_t ... EBIDX%3AIT http://www.ebay.com/itm/320898688214?_t ... EBIDX%3AIT Think either one of these are worth bidding on??
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
User avatar
cgrey8
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Posts: 4055
Joined: Fri Dec 10, 2004 8:23 pm
SM: No
Location: Acworth, Ga (Metro Atlanta)
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Re: Cam lift

Post by cgrey8 »

I wouldn't mess with the FMS or World Heads. The ones in that link are probably a derivative of the GT40 casting, only put into aluminum...thus not that much of an improvement over what you have. A while back, I remember studying the flow test numbers of about a dozen heads done by MM&FF. The FMS heads were always very low on the list. Here's a link to to the flow graph in that Group 1 article:
MM&FF Ultimate Guilde to 5.0L Cylinder Heads (flow page)

AFR has all 8 parts of that MM&FF series posted on their website if you want to read the entire article. It's an interesting read, but you'll want to focus only on the Group1 heads. The higher groups are for higher levels of performance.

As for the 2nd link, I don't see a brand on them. What I do see is it says the plug is angled and they are fast-burn. I don't know if that's "normal" or if that means they've altered the plug angle to be like GT40p heads which are also "fast burn". If they do have altered plug angles, then they may suffer from the same shortcomings the GT40p heads do which is the inability to use standard headers. Before I bought them, I'd ask that question along with flowsheet data. Without flow numbers, it's somewhat of a gamble as to just how good they are. Personally if I were going to spend money on aftermarket heads, I'd stick with name brands I had confidence in like AFRs, TFS (but only if I could spec compatible pistons), Holley, Edel, Canfield, & Brodix because I am pretty confident of their quality and performance. Those companies have a good reputation for a reason...not just their quality products, but also their customer support. The guy that gave me my Crane cam had a set of TFS heads that came warped from the factory. After contacting TFS, their CS guy admitted they had a run that were faulty out of the machine shop, but they thought they had caught all of those before they shipped. Because what he was describing was exactly what they were aware of, they shipped him new replacements no questions asked and paid for the shipping of the faulty ones back and gave no hassles about it. I'm not sure I'd get that kind of response from an unknown brand.

In his case, he bought new. Although here's one of the places where I wouldn't hesitate to buy used. There's lots of great used aluminum heads out there on eBay. Back when I looked years ago, I recall that the AFR185 heads held their value pretty well so buying used didn't save you much. However the AFR165s seemed to go for quite good prices used. And I didn't get why. People seem to have a resistance to them for some reason. On a 302 or mild stroker, they are GREAT heads. There's only minor differences between them and their AFR185 bigger brothers and would be a PERFECT upgrade for a boosted 302 if the price was right.

The TFS TW heads tend to be a great head too. Back 5 years or so, they were the absolute best-bang-for-the-buck heads to have. They had flowrates VERY near AFR heads and for about 1/2 the price. Since then, their prices have come up but they are still a great head. The catch is they have altered valve angles (hence the Twisted Wedge name) and as such they usually require TW-compatible pistons which have valve lashes for both std and TW heads. Notice this piston has the obvious dual lash design:
Image
Since you don't have control of the pistons you are receiving in your short block, I wouldn't bet they are TW compatible so to run TW heads, you'd have to modify the pistons. I tired to attach a picture of an obviously modified piston, but between my company's firewall and the forum attachment quota not letting me upload files, I couldn't add it. But there are images out there that show stock and aftermarket pistons that are modified to work with TW heads. You can tell they are modified when the 2nd lash has rough grind marks relative to the mirror-smooth shiny surface of the other lash.

FYI, if you do replace the heads, one of the things you'll notice is your boost pressures will come down from what you are used to today. Don't be alarmed. That actually means you are pumping more air and the booster isn't having to work as hard to push it so that's less power the engine is having to feed the booster relative to now. Seeing lower boost pressures after making a head change or adding an innercooler is common, and actually an indication you did something "right." Seeing the pressure go down as a result of ONLY a cam change where the cam was replaced with a more aggressive cam often means you are loosing air & fuel out the exhaust (i.e. you are actually loosing HP and burning more gas).
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Re: Cam lift

Post by v8ranger »

Thank you for all the info.. Heads will have to wait for now.. If money wasn't a problem I would get heads you have recommended. Like I said before, I can only afford one melt down at a time right now.. So for now the heads I have will have to do.. Unless I hit the lottery, but you have to play in order to win lol... Maybe my wife will win and feel sorry for me and buy me them, probably NOT though..lol...
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
User avatar
cgrey8
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Posts: 4055
Joined: Fri Dec 10, 2004 8:23 pm
SM: No
Location: Acworth, Ga (Metro Atlanta)
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Re: Cam lift

Post by cgrey8 »

I perfectly understand. Projects have budget boundaries that are immutable. And it's up to you to decide what the best choices to do with the budget are. I just want to offer as much infomration and opinion for you to consider so you can make a more-informed decision about how the budget is best spent.

That being said, has the short block already been purchased?
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Re: Cam lift

Post by v8ranger »

Yes. Still waiting for it to show up...
1986 Ranger with 1990 5.0 HO roller motor
Ported GT-40 heads
Duel plane air gap intake with 750cfm Holly
Paxton SN93 Supercharger with 3 1/2" pulley.
8 to 9psi of boost??
T-5 trans
Large tube shorty headers
Stock posi rear end
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