Narrowed it down to a 427 or 440 sbc!

[Guest Fast Frog]

Over a month ago, I asked about the possibility of a big inch sbc in the form of a Bowtie block. Since then, with your help and info, I've made a jillion calls and researched several articles (the main one being The Best of Hot Rod Mag, re: Big inch small blocks). I have now narrowed my choices down to 2 or 3 options based upon the following: 1) It needs to be a street/strip combo-in other words, primary power in the 2500 thru 6000 rpm range. 2) It has to have a "decent" idle-so a real wild cam and super high compression is out! 3)I want it to run on pump premium with minimal, if any, octane additive. And 4) The engine configuration with accessories must be must be as close to stock setup as possible. I don't want to start tearing up and redoing the engine bay for a few HP more. So here goes!

 

BLOCK: The block of choice, at this point in time, appears to be the Dart Iron Eagle/Little"m". This block is particularily designed for a big inch sb setup up to 454ci.

A couple of engine builders have sucessfully made 482 ci by boring the snot (4.25") out of the cyl bores and a 4.25" stroke, but the piston wrist pins sit in the lands and groves where the rings are located. By keeping the stroke at 4.000" and under and the bore at 4.190" max, a 440 ci sb can be made by using the appropo 4.000" 400 crank and appropo length rods.(6.0 I believe). And the deck ht is the standard 9.025 which means the block config is the same as a production block like I've got in the car now. To do a 454ci setup, the block of choice is the one with a raised deck to 9.325 cause you need a stroke of 4.125 and you need the xtra clearence to get the correct geometry for the rotating assembly. This block also has the raised cam config for higher lift and ability to use a standard base circle cam. The prob with this hi rise block is that it is .3 inch taller and thereby almost .3" wider on each side where the hds affix. That's .6". If you run 1 3/4" or 1 7/8" headers, you add 1/4 inch each side for a total of 1-1.1" width. Spacers are then needed between a standard intake and the hds, and we all know how tight the fit is with a standard sb and 1 5/8" hdrs-so a 454ci is not an option for me.

 

A 427 is a 4.19" bore and a 3.875" stroke. A 434 is a 4.185" bore and a 4.000" stroke.

 

HEADS: Paul Pfaff, of Calif, likes Dart and Victor Jr. Shaffiroff, back east, likes Airesearch hds. But the rising star appears to be the Brodix Track 1 alum hds. This hd has 215 cc runners, 67 cc comb chamber, 2.08/1.60 valves, take lift up to .700 and will take chevy config hdrs. It's CNC machined and is one step below a fully ported pro-stock hd. Brodix will match and port at the factory, to accommodate your intake of choice and hdrs of choice.

 

CAM: I'm partial to Crane Cams, but I know that there are other hi quality cams to be had. The cam I'm considering is Crane's solid roller # 118521. It has a fair idle and good power up to 6500rpm. Duration is 244/252@0.050" and .543/.561 w 1.5 rockers and 112 deg lobe sep. With 10.5 to 1 comp, HP for the 427 is 515+/-, 434 is 512+/-, 440 is 510-all at 5500 rpm. Torq comes in at 4500rpm for all 3 engines @ 542 for 427, 546 for 434 and 550 for 440. (used dyno 28 and dyno 2000 to get HP data). Will probably use Sanderson 1 3/4" or 1 7/8" block hugger hdrs.

 

OTHER: For intake, I'll keep the LT-1 Mini-Ram fuel inj manifold and the Accel DFI engine mgmt system. I've got almost $5000 invested in those 2 components. It would be dumb not to use them for this kind of project. I'm still pondering what kind of exhaust sys to use-side pipes or out the rear end like a stock Z setup. There are other smaller components I will go to like Edelbrock's alum water pump and Griffith alum rad.

 

$$$$: This is not a project for the financially challanged! However, It's not that expensive either. I figure I can do a 427, 434 or 440 short block for $6500+/- by keeping my Mini-Ram and the Accel DFI sys. For an intake with carbs, add $500-$700. And for anything else, the price goes up from there. After the engine is complete, I'll be looking at a T-56 tranny-another$2000+/-. Hopefully, I'll be looking at beginning this project early this summer. Whew! Sorry for the length.

 

Comments or advice??

 

Rick

 

[This message has been edited by Fast Frog (edited February 14, 2001).]

[pparaska]

Rick, a few opinions on your build up:

 

1)Octane tolerance: I'd not want to deal with ANY octane boosters. But with minimal quench height (0.035 to 0.040") you can make HUGE gains in octane tolerance, not to mention more and broader power. The recent engines built up in Chevy High Performance have brought this idea back fro the old days.

 

Another thing that adds to octane tolerance and power band width (rpm distance from peak torque to peak hp) is to use a rod/stroke ratio of 1.7 or better. It's hard to go too far with this. I'd be looking at a shorter stroke versus a longer one, if needed, and the longest rods you can find/afford. With a 3.875" stroke, you'd want a 6.6" or longer rod to get that. I doubt that would easily fit with a piston ring package that didn't have the pin in the bottom ring land. I might go that way to get the rod/stroke ratio.

 

Did you ever see that article a few years ago in Chevy High Performance (I believe) where they built a ~350ish CI motor from a 400 block and a 327/307 crank (3.25" stroke)? It had long rods as well (Ford 300 6cyl.) It made tons of torque and hp on low octane gas (over 400/400, can't remember the details).

 

I guess I go for the 427.

 

2) Heads. Wow lots of confusion on heads out there. Haven't the recent flow tests by Chevy High Performance shown that the Dart and Victor heads don't have much swirl? Also important for torqe and octane tolerance, not to mention a bit of top end power. I've also heard good things about the new AFRs, but not so good as well (Hi Ross). The Brodix Pro 1 Aluminum heads are supposedly very good in flow and swirl. I'm very keen to see some tests of the new for 2001 Edelbrock E-tec heads - the 200cc ones would be interesting for your setup.

 

3) Cams: It seems that I've heard nothing but great things about the Comp Cams Xtreme energy cams. The solid roller Xtreme series seems hard to beat as far as wide power band and great power. The XR280R (12-771-8) has a range of 2500-6500, (242/248 @.050 .570/.576" lift) and the XR274R (12-770-8) has a range of 2200-6200, (236/242 @.050, .564/.570" lift ) seem like good candidates. There is a larger one than the XR280R, but I doubt it's very streetable (3000-7000 range). Check out http://www.compcams.com/catalog/060_061.html

 

FWIW,

[Guest Anonymous]

Dude. Keep the compression down a hair and turbocharge that bad boy! A 7+ liter turbo engine would be pretty damn bad!

Man, I hate to admit it, but I could live with a giant pushrod v8 and a turbo or two on it!

 

 

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Morgan

http://z31.com/~morgan/s30

http://carfiche.com

[Guest Fast Frog]

Hey guys:

 

Thanx for the tips and added info. I'm going to be taking all into consideration!! Morgan, I'd give my I-teeth, wife and 1st born (well, maybe not my 1st born)- just kidding!!-to be able to do a good turbo setup for this engine idea(not supercharger). I'd only need 6-7 lbs to have a real monster!! Oh well.... Engine bay size is the biggest inhibitor.

[Guest Anonymous]

Sounds like you have it sorted pretty good. That ought to be one giant killer for sure...

 

 

Lone

 

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http://www.bent8z.bizland.com/index.html

[BLKMGK]

Beware of putting the pins up into the ring lands. Talking to guys who've worked with sort of stuff it's a nightmare that they'd only advise doing for a full race motor. Ring sealing goes down while oil burning goes up - not cool.

 

Lastly, have you considered scaling back the engine size and slapping a blower on a milder motor? I'm not sure what your goal is but blowers really aren't that bad so long as it's not a cog pulley and massive amounts of boost. Not as much fun as a turbo but much less complex. (shrug) I'm curious as to why this idea has been rejected. I believe you could keep the engine bay intact...

 

That's going to be one nasty Z

[pparaska]

Another thing about the high rod/stroke ratio, a good chamber (high swirl), and a thin quench area is that since it cuts down octane sensitivity, it allows some pretty high compression ratios. I've seen 10.5:1 on 93 octane, and 11 might be possible with the big cam you're looking at.

 

If you're playing around with this stuff, get Desktop Dyno to be able to trade choices. Don't depend on the absolute numbers, but the trends will be spot on, especially when you put the right flow numbers in.

[Kevin Shasteen]

quote:

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Originally posted by Fast Frog:

Comments or advice?? Rick

[/b]

---

 

Rick,

 

Sounds like someone has been burning the midnight oil. Decisions, Decisions, Decisions. Congrat's on the groundbreaking of your new project-wish I could say the same.

 

A few ideas off the top of my head. First, you definately want to go with an engine that fits in the z-eng.bay w/minimal mod's. Secondly; you're gonna have so much torque in such a light chassis (240/260/280Z) I'ld go w/the smaller 427 also.

 

As for the Cyl.Heads; David Vizard's book on Modifying SBC Cyl.Heads flow tested those exast heads w/very mild porting. He tested both the 1.94/1.50 & 2.10/1.60 valve set ups. He came up w/these #'s:

 

1.94 Intake @ .500 lift/1.50 Exh. @ .500 lift

...............180cc.................122cc

 

2.10 Intake @ .500 lift/1.60 Exh. @ .500 lift

...............248cc.................170cc

 

Lingenfelter's book mentioned the Interport Relatioinship with emphasis on the Exhaust. Say your Intake flows 200cc while your Exh. only flows 100; Divide 200 into 100 & you come up w/a .50% E/I...not good. According to the flow capability of your heads Brodix/Track I has a 66% E/I w/smaller valves & a 68% E/I w/larger valves...pretty good yet Lingenfelter goes on to say that most engine builders prefer an 80 to 85% E/I relationship.

 

Another point on Cyl.Heads; to determine what minimum CC's must flow. Multiply the Peak RPM times Displacement & Divide by 3456; take that number & divide by the number of cyl's in your engine. Rick in your set up this comes to 92.66cc's; to take into account intake runner restrictions you can multiply that number by 1.5 & you get 139cc's required to reach peak torque/power. I'ld say your Brodix heads can do that!

 

About the Camshaft: Remember the late 70's & early 80's; if you wanted performance N/A car you pretty much were stuck w/Pontiac T/A's (Sorry Ford Guys-Trying to make a point here). The Pontiac's 400ci were not high in hp; but their eng's produced a lot of torque because of their bore/stroke relationships. I guess what I'm trying to say is: Dont go overboard w/the cam's profile. I'll agree that Big Blocks (Big Small Block in this case) can handle a larger cam easier than a typical small block.

 

On a previous post Myron indicated his cam's profile to me on his old ride-close to yours. It to was a Mechanical Roller. He was using 1.65 rockers on the intakes; he couldnt exhaust the gasses fast enough to take advantage of his cam's lift.

 

Another book I have on Camshafts discusses the Mechanical Roller's: Says this: A solid roller inflicts brutality on the valve train which explains the high cost of its required components. Therefore, be sure & spend more upgrading beyond what is simply needed for a typical camshaft install. Bib rollers w/lots of lift require double/triple springs to eliminate valve float & high rpm's, light weight titanium retainers w/10 degree locks, thick wall chrome moly pushrods to resist deflection. Also recommended chrome moly rocker arms studs to resist snapping under high spring loads, roller rocker arms, stud girdle to rduce valve train flex; of course a true roller timing set. One interesting note-they also suggest a camshaft w/built in Ductile Iron gear to make it easier on the distributor.

 

As for streetable, that's a relative term. Usually 112-114 LDA's (overlap) are considered street cam's. The more duration you run the wider LDA you'll need for an acceptable idle. I'm not wanting to discourage you-but just advising you to be very careful in your camshaft choices, Ask your engine builder if he knows anyone running something comparable to what your looking for-then you can get a first had crack at its performance/idle characteristics.

 

Sounds like you're on your way to a monster engine. Dont get in a hurry, ask a lot of questions & then make an educated choice. Once you've made that choice it will be a good one because you will have researched it thoroughly; after making that decision dont look back & enjoy your ride!

 

Hope I didnt ramble; wish I were starting my project!

 

 

[This message has been edited by Kevin Shasteen (edited February 14, 2001).]

[Guest Fast Frog]

Thanx Pete:

 

I do have desk top dyno. I've got Dyno 28 and Dyno 2000. I've also have Accel's Calmap 6.1 Injector Sizing and HP Calc program. Generally, all three are within 10 HP of each other. Yes, you're right, trends are what these simulations are best for.

 

BLKMGK: I've done the turbo and SC scene with this particular car. I had an 82 L28T engine in this puppy with 3 diff turbos over an 18 yr period, and when I went 383, I had a Paxton (not the best choice). I'm not ruling out dropping the CR to 9 or 9.5 to 1 and checking out a Procharger with 5-6lbs of boost. Thanx for the tip!

 

Thanx again guys!!

[Kevin Shasteen]

quote:

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Originally posted by Fast Frog:

Thanx Pete: I do have desk top dyno. I've got Dyno 28 and Dyno 2000.

B]

---

 

Hey guys, I've got the old Desk Top & was wondering if the improvements in the Dyno 2000 make it worth getting. The old Dyno was fun in that it was the first Computer Dyno I purchased but I didnt feel I was able to fully customize as I would have liked. Does the new set up allow for more options than the first Dyno set up allowed?

 

Kevin,

[Guest Fast Frog]

Yo Kevin:

 

Yes, Dyno 2000 does allow more options, particularily, forced induction. You have to play with the forced ind part of it to get it to portray what you're looking for. Dyno 2000 is in a MicroSoft Word format, so if you're not accustomed to using Word, it will take some practice to get around in it. Aside from this, I've found little diff between this and Dyno 28.

 

Rick

[pparaska]

I believe Ross has used both. I only have the 2000 version.

 

I like it, but it bugs me that you can't put in more info on the cams. Of course, getting more info on the cams is difficult unless you measure the lift/rotation relationship yourself (not hard to do). What I'm getting at is you have to play games telling it how aggressive the ramps and lifter accelerations are by picking from Hyd. flat tappet, Solid flat tappet, and Roller type cams. They tell you to not use Roller for the street rollers.

 

The problem is this choice has a HUGE impact on engine performance, in the real world and using the software. I'm capable of measuring my cam's lift/rotation curve, and I want to put it in. I'd also love to get that data from the cam makers, but that'll never happen (trade secrets, etc.)

 

It'd at least be nice to know what kind of motion the cams are using (cycloidal, harmonic, etc.) and be able to play with those parameters as well.

 

Other than the Cam guessing game, I like it pretty well.

[Modern Motorsports Ltd]

quote:

---

Originally posted by Fast Frog:

rear end like a stock Z setup. There are other smaller components I will go to like Edelbrock's alum water pump and Griffith alum rad.

---

 

Wow, sounds like great stuff. One comment, like Griffin I much prefer Stewart Components for water pumps. Very race proven and others I crossed in other lists have had good experience with them. I'm running one of their's with a Robert Shaw t-stat. http://www.stewartcomponents.com/

 

Something about some racing companies that don't advertise a whole lot but still get great feedback and hang around attracts me

 

 

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Of all the things I've lost, I miss my mind the most.

[Kevin Shasteen]

Originally posted by ChrisCloude:

For those of you interested, the article Pete mentioned regarding the 350 using a 400 block and 327 crank can be found at:[/url]

 

Chris,

 

Pretty interesting article Chris. If one could assume a 90% Volumetric Efficiency from that motor; it would put out RWHP or 390 torque & 370Hp...not to shabby. I believe that bore/stroke come out to 352ci.

 

I too was a little unsure about the piston pins so high/close to the ring lands; longevity may be suspect. Still an interesting concept.

 

I liked the fact it ran on such low octane; that alone would pay for the engine's build over time: if it proved durable.

 

For a little less pressure on the valve train I would prefer maybe using a 1.5:1 rocker & just get a slightly larger cam such as the the next size Hydraulic Roller Comp Cam: 280HR. That cam gives the same effect as the 270HR w/1.6:1 rockers except the 280's duration goes up 9 notches from 215 to 224. I dont know, maybe the cyl's would seal better w/shorter duration & the same lift using the 1.6:1 rockers. Both cams are ground w/110 LDA's.

 

Still, an interesting read.

[Guest Anonymous]

For those of you interested, the article Pete mentioned regarding the 350 using a 400 block and 327 crank can be found at:

www.airflowresearch.com/Articles/A3-P1.htm

 

I imagine building such an engine would be fairly easy. One could use the 400 block, 400 pistons intended for 5.7" rods, a 327 crank and readily available Eagle 6.2" rods.

[Cable]

TTT