FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: jayb on February 27, 2016, 09:14:40 AM
-
Just got my copy of this magazine and was surprised to see an article on building a 427 stroker! Kind of an odd build-up, though. This engine was really optimized for low RPM operation. They went .050" over on a 427 sideoiler block, and added a Scat 4.25" stroke crank, rods, and JE pistons to get 488 cubic inches. But they limited the compression ratio to 9.9:1, and went with a pretty small hydraulic roller cam that was comparatively large on the exhaust. Cam specs listed in the article are 235/249 @ .050", with .577/.561 lift and 107 LSA, installed straight up. The engine used near stock Edelbrock heads, rather than some high riser heads that they had on hand; the article implied that they may not have had an intake available for the high riser heads. It also used a PI intake and a Quick Fuel 850 carb, and a Mallory Unilite distributor.
The article claims a nearly unbelievable torque of 676 ft-lbs at a very low 3900 RPM, and only 561 HP at 5100 RPM. At 3000 RPM this engine is already making 654 ft-lbs. The peak torque is nearly 1.4 ft-lbs per cube, which is a great number.
I've never built a 427 that is optimized for this sort of low end torque production, so I don't have any direct comparison data to a different engine, but if those numbers are right, that motor is a real stump puller...
-
So......you think those dyno numbers may be suspect?
-
Well, I'm not sure. Based on what I know about dynos, I'm always a little suspicious of really good numbers. But that motor is optimized for a range of power production that I don't normally use. For example, the 427 stroker dyno mule that I did for my book peaked at around 625 ft-lbs of torque, but that was at 5000 RPM. It also made 675 horsepower at 6900 RPM. That engine was optimized for power production in the 5000-7000 RPM range, whereas the engine in the Car Craft article seems to be optimized for power production 1500-2000 RPM lower than that. So the Car Craft numbers could very well be correct, but I'm interested in feedback from anyone else who has built a similar motor, to see if they saw a similar torque number.
I'd have to say though that I really don't understand why the engine was built the way it was. You've got a 7000 RPM capable shortblock, and you cripple it with compression and cam that minimizes horsepower production. Maybe this has something to do with the vehicle (or boat?) that the engine is going into, and what the RPM and fuel requirements of that vehicle are. For any normal street car, though, 650 foot pounds of torque at 3000 RPM, which is what is claimed for this engine, is practically unusable. You could give up a whole bunch of that torque and not see much difference on the street, while making another 75 HP after 5000 RPM.
So, I'm not saying I don't believe the numbers, I would just like to know if there are similar builds out there that exhibit similar performance...
-
Jay:
I read these articles and then apply the "magazine dyno" correction factor; subtract 10%. I let my dad borrow your book so I can't look up the results, but has any combo ever made over 500 HP with a PI intake?
-
Their TQ is some kind of impressive for fairly mild parts. And those cam specs are damn close to Comps Mutha' Thumpr.
EDIT>>>>http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1485&sb=2
-
for a street driven car as opposed to a drag car, that there just might be a very fun ride. and last forever.
-
Jay:
I read these articles and then apply the "magazine dyno" correction factor; subtract 10%. I let my dad borrow your book so I can't look up the results, but has any combo ever made over 500 HP with a PI intake?
Sure, my 427 Sideoiler dyno mule made around 540 with a PI. I didn't run that intake on my 427 stroker dyno mule, but it would certainly have made more on that one. Also, for what it's worth, the magazine's don't always print bogus dyno numbers; the ones on the 390 stroker I did for the Car Craft article in 2008 were printed verbatim with my dyno data, which was completely accurate.
-
for a street driven car as opposed to a drag car, that there just might be a very fun ride. and last forever.
Not to mention, it'd make a great engine for your dumptruck.
-
Oh man....the dump truck comment hurts a little. My 489 was a ported RPM, 242/248 @ .050, but the heads were worked a bit and it is 10.7. It sure wasn't a truck motor then :) with only slightly more cam
That being said, I ended up lashing the cam as tight as I dare, from .027 hot, to .010 cold, and added a ported EFI Victor and it'll still pull off idle in 5th :)
I do think that build is a bit odd, cam seems late at 107, compression seems low, including DCR. I wonder if it's even accurate, it's not easy to get a 488 to that low of a static number. Also, seems like they cranked the cam back to offset the small intake lobe and of course, the PI probably starts wheezing pretty good with 488 inches under it.
If it is a Thumpr cam of some sort, which I assume it is, it likely sounds better than it runs. Although guys seem to have good luck with those lobes, that tight LSA with all the exhaust duration hasn't impressed me much in the one I used on a 396. Sounds awesome, but doesn't have the oats a 270S would
-
Not to mention, it'd make a great engine for your dumptruck.
LOL! I was thinking the same thing! (Sorry Ross ;))
Talked to Blair P this morning about this, and he is rather skeptical of the 675 ft-lb number...
-
If I ever meet Ross, I'll be sure to quote him for a custom Gooseneck hitch install.
Sounds like the next FE related CarCraft article, "Pony car that hauls an actual Pony."
-
I expect nothing less from Chebbie Craft- make the Ford look lame, makes the Chebbie look better ::)
After they came to Napa and ignored a cherry genuine Webered USRRC/ FIA big fender 289 Cobra, and an original race GT40 (#P1009, very early car) in favor of a fake 69 Z28 that belonged to a friend of mine, started out as his neighbor's wife's 307/Powerglide stripper- and they put it on the cover of the mag LOL...
-
Not to mention, it'd make a great engine for your dumptruck.
LOL! I was thinking the same thing! (Sorry Ross ;))
Talked to Blair P this morning about this, and he is rather skeptical of the 675 ft-lb number...
Hey, I've got the dumptruck!! I say we try it out!! ;D ;D
(http://i43.photobucket.com/albums/e363/cjshaker/IMAG2262.jpg) (http://s43.photobucket.com/user/cjshaker/media/IMAG2262.jpg.html)
-
A 10:1 compression, 488 inch engine with 235 int duration and a 107 LSA is going to be an odd package indeed. I am also highly suspect of a 1.4 lb per cid torque number with off the shelf Edelbrock heads. Most moderate street stuff comes in between 1.1 and 1.2 per. The better EMC engines frequently go between 1.4 and 1.5, the winner might sneak past 1.5. I'd really like to see the raw data and cell conditions on that one.
-
That's a Thumpr camshaft. Probably get a little more torque with a tight LSA, but I too would be *very* suspect of 1.4 lb-ft /cube torque numbers.
I did a similar engine, it's on Jay's dyno results page. Little less camshaft, but my peak was 620 lb-ft for 482 cubes. Made 538 hp as well. That's with BBM heads (should be heads and shoulders above an out of the box Edelbrock), a modern ring pack, 9.7-9.8:1, and a 224/230 @ .050" hydraulic roller. I don't think there's anything I could have done to that engine to get another 50 lb-ft out of it......
-
I would be interested in more info on this combo. The low RPM would do wonders for the motor I want in my 56 COE that I want to use for my toy hauler. I can go with diesel, but finding one that fits the truck is problematic. FEs fit the chassie perfectly. I need the grunt for towing.
-
Just picked up a copy and read the article in more detail. Pretty much getting closer to calling this one impossible.
Sucks because we are always looking for greater media visibility for the FE, and an example that looks "wrong" does not do us many favors when we can't honestly meet those kind of targets. It's full of wrong information, incomplete information, and just plain misleading coments. Damn.
The 654 torque at 3000 is well beyond any combination I ever see. We just ran a 465 inch engine yesterday - not an FE, but reasonably similar level of prep to Edelbrock heads - and saw the same 1.2 pounds of torque per cube as we see on the FE strokers. Its not magic, its physics. Stuff can be shifted around, but with street combinations its in increments, not in huge steps. That engine was over 100 pounds lower at peak than the magazine example. Us FE guys are good - but unfortunately we ain't "that good".
The magazine engine is using an electric water pump - adds about 12 HP at peak. The headers they mounted upside down cost about 12 HP at peak. I have tested both of those deals personally.
They quote the Edelbrock flow numbers at 270 @ .600, which is about 15-20 cfm inflated - but the heads could meet that number after the valve work they reference so I will give them a Mulligan there. The Pro-Comp rockers are gonna be short lived with the 165/430 pounds they claim for the chosen springs.
They say the OE windage tray won't clear the stroker - but it does. They reference the 130 psi high pressure pump but don't recognize that the pump is designed to work in concert with the rear mounted bypass to deliver fairly normal oil pressures. They say you need to plug the lifter feeds to run a solid cam - but you don't. They ran at 34 degrees total timing, which seems really short for a normal Edelbrock head package.
A power peak at 5000 seems really short and probably just flat out wrong even for a timid build. The 465 motor I used as an example had a 235@.050 cam and peaked just at/just under 6000. I have probably run a couple hundred FE stroker hydraulic rollers ranging from 218 to huge at .050 and never had one peak that low. A recent 482 with 218@ .050 still peaked at 5500 RPM.
I hate to say it - but I think this is a modest build coupled with a bad dyno. Those guys will probably hate me from now on. I think that on my pump that package would deliver around 475-500 HP at 5500 and 565-580 pounds of torque at around 4000. If they were brave enough to bring it I would dyno it for free just to see. I'd let them calibrate and run the cell and I would just watch....
-
Where was it dyno'd? Westech?
-
Someplace named RAD Automotive in Massachusetts. Their website shows a whole bunch of newer high end equipment, but just has manufacturers images. No idea at all whether they are good, bad, awesome or average. But the dyno numbers in the article just look pretty darn goofy.
-
You are right, guys like this ruin it for the rest of us. Unfortunately, horsepower sells and the guy with the biggest dyno is gonna get the highest accolades for his "abilities".
It's a Catch-22......customer calls up and asks for something similar to the build in the magazine, then we have to spend 30 minutes talking about how it's not accurate.
Walmart is still hiring greeters, Barry.
-
Someplace named RAD Automotive in Massachusetts. Their website shows a whole bunch of newer high end equipment, but just has manufacturers images. No idea at all whether they are good, bad, awesome or average. But the dyno numbers in the article just look pretty darn goofy.
I knew those guys well, they used to do most of our machine work when we had the shops in Ware and Wilbraham MA (1 town each way from where he is)
The guy who started the business is likely passed by now, or at least likely not working. He was an old FE guy and I'd say he was sharp with old FE parts, but nobody was doing anything fancy then.
I haven't talked to them in 20 years, but they seem to be popping up here and there. They were honest guys with a small shop, they have expanded though, no idea how they pulled those numbers. IMHO they were machinists first, builders second, no idea who they have working there now though
-
Brent, you'd make a fine Walmart Greeter.... Tho I think there is an age requirement and you may be too young to do such a job.
I don't really understand the fascination with a dyno, unless you are racing.
For a street car, 99% of the power you want/need is under 4000rpms which a dyno isn't all that great at measuring. That said, it really needs to be trial tested in vehicle. I'd happily trade 25hp at 6,000rpms for better balanced power across the board.
Sure for fine tuning it'd be nice, but is it THAT much nicer than a good A/F meter and some careful tinkering?
I can understand the desire to dyno test an engine for the pro-builders, or at least I couldn't imagine sending a full "finished" engine out without being able to test fire it and run it up to speed with a load. Also handy for the northern weirdos during the long long long cold winters when you feel like dyno testing a variety of engines with 75 different manifolds. :p
(just messing, Intake Comparo is probably one of the cooler projects I've seen)
-
I've been called lots worse than a "Northern Weirdo" LOL! The dyno was one of those Land and Sea deals, I don't know how/if they are calibrated, but it had to be way out of wack unless the numbers were fudged. Blair P sent me some dyno results from some other 480" FE builds this morning, and his opinion after reviewing those is also that there is no way that combination makes the torque number shown.
Also for reference, when I put the article together for Car Craft the editor demanded to see the actual dyno files, so he could confirm that they were legit. Of course he would have had no way of knowing if the dyno was out of calibration, but in a case like this I think I'd tend to blame the dyno shop rather than the magazine.
-
I'm a big fan of power in a usable range, and 6K power numbers are pointless to me.
Flow numbers also fall into the "just when am I going to use .600 lift at WOT in the real world" category.
Maybe those stories numbers are due to NOT hogging out the ports in the heads?
-
Most dynos have a pretty hard time hanging on to a strong engine at 2500 RPM wide open throttle unless you overspeed the pump and crank up the pressure (I have done that a few times). Realistically once you hit wide open throttle on even the mildest engine you will blow past 2500-3000 RPM awfully darn fast. The driving type stuff is part throttle tip in and transients which are much harder to simulate. I can put on a load and cruise up and down in RPM, but I have no way to really know what kind of load the actual car is going to require.
I started putting correction factor and cell temp & baro in my dyno reports as a way to combat this sort of thing. Brent and others posting in the FE community have also gone along with this - allowing the data to be reasonably comparable.
-
They forgot to include the two itty bitty 56MM T4 Turbos that are completly tapped out at 3K RPM?
I am FAR from an expert on these engines - but it does seem pretty incredible to have numbers so out of line with norms ... it is also really sad / odd to see them do a 427 as a stump puller... I'd not be surprised if the authors of the article were not born when that motor was in production and didn't take the time to actually familiarize themselves with the engine family.
Seems like a great opportunity for "someone" who lives in the FE world to offer to provide a better example for their next article...
-
Well, most of us here probably weren't born yet (or very long before) the FE was made. And the only thing "427" about the engine is the block, which was bored. Lot's of young guys know how to build and tune engines and run dynos.
It's a shame that the numbers are probably less than accurate, but it's still cool to see an FE engine in the magazines. And I actually like to see them built for different purposes. I think a torque monster combination is an interesting build (mostly when it's done by one of the FE communities builders though); it just shows another side of an engines purpose, street, race or utilitarian. I've had FE's in my trucks for the last 30+ years, and I'ma stickin' with them 8) (mostly because I can't afford a $45k-$50k+ new truck >:()
-
With that kind of torque down low,if true, it should blow the tires off cracking the throttle in 3rd gear with a 3.25 rear gear in a Torino! Don't believe those torque numbers either.
-
Jay I'm confused your whopping on the only 9.9:1 Compression Ratio?.... "they limited the compression ratio to 9.9:1, and went with a pretty small hydraulic roller cam that was comparatively large on the exhaust. "
For "street driving" certainly not your Drag Week street driving on pump gas 93 octane isn't 10.00:1 a good/safe figure? ............Personally I like the idea of a building a 427 to have the power curves of a production 390GT325HP & 428CJ/335HP except on steroids and busting the tires loose at 2,000rpm and starting to gasp at 5,500rpm.
-
Sounds like you just want to smoke the tires everywhere you go, BB. With 482 cubes they could have gone a little higher with cam and compression, and still been able to blow the tires off at will. Maybe it was going into a very heavy vehicle and that's why they built it the way the did...
-
Just what I need to replace the 8 mpg 460 MPFI in my '97 F-350 .. it's not very powerful, even with the #785 roof cut off the van body ...
==