[71 CAMINO]

I'm going to be building a BB 427 over the next yr. to yr. and a half. I'd like to get your thoughts on what I have in mind for this engine. I already have the block, crank and heads. I plan on this engine being high reeving, power being in the 3000 to 8000 RPM range--Not sure if I'm going to run a single 4 on it or Dual Quads, so far I'm Leaning towards the Dual Quads, they would be set up progressive.
Drive Train & Suspension

Transmission--TKO 600 W/.64 overdrive
Bell housing--McLoed sfi
Flywheel--Centerforce Steel sfi
Clutch--Centerforce DFX sfi
Rear End--12 Bolt w/Detroit Trutrack
Gears--Richmond 3.55 ratio
Rear suspension--Global West upper & lowers w/Del-A-Lum Bushings
Front Suspension--Global West Del-A-Lum bushings on stock A-Arms
Springs--Global West, Lowered 1" front & rear w/air bags in rear springs
Engine

Block--Mark IV 454 .060 over
Main Bearings--4 Bolt Splayed Centers, 4 Bolt Standard on both ends
Heads--RHS Alum. Retangle Port, 320 Runners, 119cc Chambers
Crank-- 3.75" Stroke GM forged steel Nitrided knife edged
Pistons--SRP 11:1 compression
Rods--Eagle H-Beam Floating
Cam--Isy Solid Roller .750 lift
Lifters--Isky Red Zone Solid Roller
Pushrods--3/8" Chromoly
Roller Rockers--Comp Cams Pro Magnum
Valve springs--Comp Cams Beehive springs
Main Studs--ARP
Head Studs--ARP
Rocker Studs--ARP
Rod bolts--ARP
Bearings--Clevite
Rings--Plasma
Exhaust--Full length headers w/3" or 3 1/2" w/X crossover--run to rear

* This engine will go in my 71 Elky that now has a 402 (396)

This setup is 99% for the street, I like the 3.75" crank for the fast,high reeving. Its to run only on pump gas

 

[dadeo-3]

I run a high reving 427 on the street as well. I would recommend running a rev-kit. It is cheap insurance for an 8,000rpm big block with a roller cam.

 

[1969ss396]

That sounds like a great combo for the street. I have ridden shotgun in a couple of 427 cars. They love to turn up quick.

 

[Guest]

3.76" crank here!!

DON'T use head studs b/c you may have ta pull your engine to get a head off!

I'd bore her .125" over to make a 452" out of her b/c cubic inches and bore unshroud is where it's at here.

Just sonic check her first is all to make sure she can stand being poked that big!!

And if I was to ever do this, I would make this one!!

4.625" b x 3.60" s = 505.3" BB engine that will run just like a Z-28!!!

But I really want to make a 4.625" b x 4.375" s = 588" BB engine instead!!

pdq67

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[ironhead]

The beehives scare me.When they fail..they have no inner spring or dampner to return the valve to seat.In the same breath..they appear to solve valve float with the heavy train weight.I will patiently await others findings.

 

[Neal Wright]

Not an expert (or even novice) ... but an OD & 3.55 don't look like enough gear for a high-rpm motor? You may want to look closer into either your gearing or your engine design.

Thanks, Neal

 

[Mike Feudo]

Definately agree about the gears and the OD. You won't like it unless you are cruising at 120MPH.

 

[71 CAMINO]

The Tremec TKO 600 gives me 4 close ratio gears for street driving and the .64 overdrive 5th gear gives me 70 mph on the highway @ about 2000 rpm's w/28" tires. I know thats just loafing along at that speed and rpm's but I figured that if anybody wanted to play with me at that speed, I could always shift down to 4th or 3rd for its power band then figured I'd loos them by the time I got to about 200 mph in 5th :beers:

 

[jbird]

I believe you will need a spring with at least 2" istalled height with that lift, and those heads. The largest beehive I see has an installed height of 1.925, and only 140Lb seat and 400Lbs open pressures. You will need about 250lbs seat and about 700lbs open with a cam like you want. The Comp 959 would probably work. The beehives work well for a hydraulic roller though.

I don't believe SRP makes an 11:1 piston for a 119cc head for a 3.76 stroke. They do have a small dome piston that would give you about 10.6:1 with a 112cc chamber. The heads will have to be milled considerably.

I would spend the money for the splayed caps somewhere else where it will do some good.

I also believe your 427 will act like it is in ventricular fibrulation at 2000 rpm, under load at cruising speeds. Just too much cam and too much head to cruise at 2k with a manual trans. JMHO.

Oh, and pdq(Paul), I don't think he will want to bore his Mark IV 454 block +.125" to drive on the street. Now if it were a tall deck truck block, maybe!Good thought though!

 

[CDN SS]

3.55 and .64 OD and any cam over [email protected] will not work well I run a 3.73 and .82 OD with a 250 cam and it wont run well until at least 2500 .....do more real world homework .......not to mention those Red Zones will want more oil than they will get at 2K on extended highway runs .... Sounds like a mismatched combo, like others have said 11.1 and 119 chambers 320 head ?? foe the street with only 427 ci ????

 

[71 CAMINO]

3.55 and .64 OD and any cam over [email protected] will not work well I run a 3.73 and .82 OD with a 250 cam and it wont run well until at least 2500 .....do more real world homework .......not to mention those Red Zones will want more oil than they will get at 2K on extended highway runs .... Sounds like a mismatched combo, like others have said 11.1 and 119 chambers 320 head ?? foe the street with only 427 ci ????

What would you recommend for a solid cam? using my heads and the tremec tko 600 w/.64 od and the 3.55 gears. I could change the gearing as I haven't bought them yet, am buying next week. I could go the 3.73s. I need to stay with the heads and I want to stay with the 3.76 crank and going to stay w/ the .060 over on the block. Am also going to change the valve springs as recommended. I am trying to get as much out of this engine as I can get Keeping it basically a 427 w/solid rollers and still driveable on the hyw and all on 92 pump gas. All ideas appreciated

 

[godsend]

Is the heads bought?

Build it for E85. Use 13.5:1 in compression. Pump gas wont don the trick in high revs... It wont burn fast enough.

This sounds like a bowtie or something with splayed caps? Bore it to 4.5 and use the 3.76 crank for a 478. Thats my combo. Use titanium retainers. And try a rev kit.

With 320cc rect heads large cam you want to cruise @3500-3800rpm to get a high effiency.

Build it for EFI and get lost of the power robbers ,)

 

[Busted Knuckles]

Sounds a lot like mine right down to the heads. I'm using a CNC Bowtie block, though, bored to 4.600 for 499 cubes. Static compression will be about 11.4:1. My Pro Toplines have had the CNC chamber option, they'll get a bit of massaging but not much - these castings are very nice out of the box. My cam will be a solid roller, 264/270 with .725 lift and a set of Jesel shaft rockers and Isky Red Zones with street option. Mine goes into an '81 Corvette with a nodular case, nickel gear Super T10 and beefed up rearend. I already had the block and the Corvette when I stumbled across a Lunati Pro Mod 3.75" crank, decided to build my 2006 version of an L88 with a huge cam, huge bore and good flowing heads.

 

[427L88]

Mine a REAL street version with a solid flat tappet, and a "baby" one at that.

For a max efffort 3.76" motor, I'd go 4.600" bore. Now, that's a 505 that'll rock OLD SKOOL! Ok,,I didnt win the Lottery last night so...
some practial thoughts....

Think of the original design criteria of the L88 series of mills... 3800-7400 is the power band I beleive they were shooting for.

Harold, you say the word "highway" a few times. .750 lift and the springs needed to run it are NOT highway. Brother, that's OFF ROAD if I ever did know it.

I have had both the 074 and 990s on my mill. I actually think the 074s were smaller, and my old buddy did a real nice bowl blend. The car was faster with the alums for that reason, and I have no doubt in my military mind ET will prove it this year. And I do hope my azzdyno is off.

Consequently, I have concluded that the IDEAL head for an old skool , but 21-st century L88 ( 610+ hp vs 560 !!! ), is non other than

Tony's AFR 305 CC BBC head. Period. They'll carry that mill at 7500 all day long, and give you one helluva power peak ( peak TQ) right near 5G and hold it until 7500. At least by my theoretical reckoning.

I'd spend the dough on thermal coating the piston tops, and mybe even the chambers.

You want a high a DCR as you can get away with, since compression is KEY to give the short stroke a respectible, and comparable to long stroke, compression torque figures.

I.E. Mr. Waters' 427 will SMOKE a stock 502, even a hopped 502.. that is if he EVER RUN IT! Mine will only run with a stock 502, and maybe not even now. ( I deliberately dropped CR from 10.55 to 10.15.( DCR from 8.5+ to 8.2) ... pre-ignition ping was becoming an issue)

Again, Squeeze is key to the short stroke. You can build a respectible 9:1 454, not a 427,. imho.

Cams... Oddly, I dont think the wide LSA hurts the short stroke. I wish I could back-to-back ET test Harold's ( UD Harold's - not yours ! ) 276/284 roller 112 lsa ( sotck as designed) and 108 lsa.

FItting the right cam to a 3800-7500 rpm range, in a 427/433/439 discplacement take near 250 duration, but not much over it. In my REAL sreet context, I never wanted to take it much above 250.

The real number you'd want from a roller cam, I should think, is a .200" duration at near 170. Now you got all the of the L88 real power band and tha'll take it to 7300 peak. Again, rough reckoning. Now, what Harold Brookshire needs to get a good 170+ .200 duration in a reasonably durable lobe profile ( easy on springs, etc), is the question with the cam.

MyboTy - man, you're livin' my dream. Hope you dont mind if I pay close attention! :thumbsup:

 

[427L88]

Mine a REAL street version with a solid flat tappet, and a "baby" one at that.

For a max efffort 3.76" motor, I'd go 4.600" bore. Now, that's a 505 that'll rock OLD SKOOL! Ok,,I didnt win the Lottery last night so...
some practial thoughts....

Think of the original design criteria of the L88 series of mills... 3800-7400 is the power band I beleive they were shooting for.

Harold, you say the word "highway" a few times. .750 lift and the springs needed to run it are NOT highway. Brother, that's OFF ROAD if I ever did know it.

I have had both the 074 and 990s on my mill. I actually think the 074s were smaller, and my old buddy did a real nice bowl blend. The car was faster with the alums for that reason, and I have no doubt in my military mind ET will prove it this year. And I do hope my azzdyno is off.

Consequently, I have concluded that the IDEAL head for an old skool , but 21-st century L88 ( 610+ hp vs 560 !!! ), is non other than

Tony's AFR 305 CC BBC head. Period. They'll carry that mill at 7500 all day long, and give you one helluva power peak ( peak TQ) right near 5G and hold it until 7500. At least by my theoretical reckoning.

I'd spend the dough on thermal coating the piston tops, and mybe even the chambers.

You want a high a DCR as you can get away with, since compression is KEY to give the short stroke a respectible, and comparable to long stroke, compression torque figures.

I.E. Mr. Waters' 427 will SMOKE a stock 502, even a hopped 502.. that is if he EVER RUN IT! Mine will only run with a stock 502, and maybe not even now. ( I deliberately dropped CR from 10.55 to 10.15.( DCR from 8.5+ to 8.2) ... pre-ignition ping was becoming an issue)

Again, Squeeze is key to the short stroke. You can build a respectible 9:1 454, not a 427,. imho.

Cams... Oddly, I dont think the wide LSA hurts the short stroke. I wish I could back-to-back ET test Harold's ( UD Harold's - not yours ! ) 276/284 roller 112 lsa ( sotck as designed) and 108 lsa.

FItting the right cam to a 3800-7500 rpm range, in a 427/433/439 discplacement take near 250 duration, but not much over it. In my REAL sreet context, I never wanted to take it much above 250.

The real number you'd want from a roller cam, I should think, is a .200" duration at near 170. Now you got all the of the L88 real power band and tha'll take it to 7300 peak. Again, rough reckoning. Now, what Harold Brookshire needs to get a good 170+ .200 duration in a reasonably durable lobe profile ( easy on springs, etc), is the question with the cam.

And I would speak to Tony about mid lift flow numbers, max'ing them, maybe by laying back the valve angles a bit shallow, so you can get by on .650 lift, which will be MUCH more streetable, i.e, durable.

MyboTy - man, you're livin' my dream. Hope you dont mind if I pay close attention! :thumbsup:

 

[CDN SS]

I agree with all the above ..... pick your cam to work with "your" heads( AFR 305's would be a lot better ) the headss will determine optimum lift and pistons /desired compression ...rather doubt any cammmaker will suggest a 750 lift cam for extended hwy drivin, spend money on good light/ stable valve train ......thats where I screwed up have the motor with power but valve train not up to the rpm task ......this winter upgrade in progress .after you have motor combo .then gear acordingly but the kind of motor you want wont cruise down at 2K pbly close to 3K FWIW I now swithching to 4.30 gear 28" tire with .64 OD .................will be about 2600 at normal hwy speeds

 

[71 CAMINO]

I already have the heads, their bare at this time but I will have to work with these heads--there actually the pro topline. I stated they were the RHS as they are the same.

 

[norvalwilhelm]

That sounds like a great combo for the street. I have ridden shotgun in a couple of 427 cars. They love to turn up quick.

Why is a high reving car great for the street? That little 427 could easily become a 496 and that is a far better motor for the street. As for being able to rev 8000 rpm what does that do?? If this is truely a street driven car build a high torque 496 that will put out more horsepower at a lower rpm then trying to rev your 427 to 8000.
RPM is what kills an engine, everything is stressed alot higher then a bigger cubic inch motor reving alot less and yet putting out more power at this lower rpm.:beers:

 

[71 CAMINO]

Why is a high reving car great for the street? That little 427 could easily become a 496 and that is a far better motor for the street. As for being able to rev 8000 rpm what does that do?? If this is truely a street driven car build a high torque 496 that will put out more horsepower at a lower rpm then trying to rev your 427 to 8000.
RPM is what kills an engine, everything is stressed alot higher then a bigger cubic inch motor reving alot less and yet putting out more power at this lower rpm.:beers:

I had a 66 GTO in 67, 1970 reworked the engine to some serious HP. Same stroke in that engine--real fast rev--real high rev--as far as it not being any good for the street goes--its great, once you drive a fast reving-high reving, high hp engine---YOU'LL NEVER GET IT OUT OF YOUR SYSTEM. As far as being practible--IT'S NOT--but on the other hand, building anything like this at all isn't practible when your almost 60. I'll probably put 1000 to 2000 miles a year on this thing. Never get as much fun out of driving a torque monster as one of these things--I know, I've had both. As far as "what does running an engine at 8000 do" ----It takes about 1 week to get the sh*t eatin grin off my face and my heart to settle down. Outside of that--not much.

 

[jbird]

Harold, if you've never seen or ridden in a well built, well engineered 496 powered vehicle, I think you would be in for a pleasant surprise. Not knocking your 427 idea, great nostalgic appeal. Throttle response on the type engine I am talking about is INSTANT. Mash the throttle a little with street tires and it instantly goes to 7k smoking the tires. I don't think you would be disappointed either way. I do think you would be disappointed with too much cam, too large heads, and trying to cruise highway miles with the smaller combo. Torque monster does not mean no HP! A similarly built 496 will make more TQ, AND more HP without a doubt. Now I know your savvy enough to make up your own mind and build whatever you want, just don't talk yourself into believing the larger cubic inch engines are some kind of tow truck engine, they aren't! Have fun with your build whatever you end up doing!:yes: