[L-78 GUY]

1969, 3:23 gears, 400 w/Stock converter,10.2:1 comp, Unported Oval port Open Chamber heads.

My goal is a car that is has ULTRA mild street manners, pump gas, nice idle, great power off idle but yet is real fast.Figured since I couldn't go with racey gears, converter,or compression I'd make up for it with stroke and cubic inches.

My questions to you guys are these, can I get away with stock 3/8 forged rods with good bolts...say to 6500 RPM and what in the world do I use for a cam.
That's a lot of cubes to fill, yet I don't want to sacrifice low end and idle...I priced out a hydralic roller and almost crapped my pants!!!But I'll do what I have to do.

Cam and rod Suggestions please?

 

[70ss496]

I just got done doing my 496 this summer. They are an awesome motor. Gobs of low end torque! I think your set up would be great with the 3.23 gears! Highway speeds would be nice. I don't run mine on pump gas, but wish I would have made it too. I can't answer your question on the rods I run forged H-beam rods that are 6.385".

I believe your going to need some kind of converter for the motor though. You don't have to get real crazy, I run a 10" Continental, it flashes to around 4000, but pulls the car around great about 1500 or so.

Do your heads have bigger valves or anything? The cam I run is a Solid 288/296F7 Ultradyne(Now get it through Harold at Lunati) it may be a bit more than one you want but I'm sure Harold can recommend something milder.

Good luck, I will say I'll probably go to a higher gear also 3.55's maybe, mine blows away the Hoosier QTP's at about any speed. I have a lot of work to do to try to hook it first though!

Matt

 

[Guest]

I ran my 9.8 to 1CR., 496 through D2K and came out 551hp at 5500rpm and 579t at 4500rpm with just a good old CC 282S solid in it, 1.75" four tube, long headers and Merlin ovals.

I'm sure UDHarold can come up with a better cam for you if you want to contact him..

Induction is just a Holley, 3310-2, 750 tuned to it and a Holley Strip Dom. to subtract a schosh down low and add it up top, thast's all..

I cann hardly wait to crank her up but I'm sloooooow and olddddd so it takes me foreverrrrrrrr.......

He, He!! pdq67

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[Cable]

http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=4;t=011834


This a good helper too!!

 

[mr 4 speed]

I really like the idea of a 496
I'd go with the 2.19/1.88 valves for sure,and for a cam,something like the UD/Lunati 288/296H would be great (specs are .550/.575 110 LSA 231/239 @ .050)
I bet in a 496 it would have a very smooth idle,and make some wicked torque.Driving around with regular street radials would be pretty slippery
Keep it simple:Long slot stamped rockers,run a flat tappet hydraulic,mild gear/convertor,and you'll have this smooth idling mad torque producing big block..just be prepared to make it hook if you go to the track (at least drag radials or MT ET streets if you're even remotely serious about any reasonable traction)

 

[427L88]

HA! Thats the motor I want to build to run through an M20 and 3.31s! Only diff is that I think 'm leaning towards a single pattern cam with around .235-6 @.050. I think it was Harold's 292 lobe, assymetrical and flipped over on int and exh and a 110 lsa.

I wouldn't do high dollar rods either, 3/8s with some prep, rebuilding and ARP Wavelocks. Unless I find a set of 6.35" rods cheap.

049 ovals with big valves fitted, 30 degree seats and some attention to the bowls. Low compression, around 9.75-ish to run on something other than hi test.

Won't be as much fun as my high rpm buzzer 427, but likely just as quick.

Yeah

, me too, I like the idea of a 496.

FWIW, last time I raced, a newly done 69 with a 496, ran a 10.85 its second run. FIrst thing he noticed was the 4.,56s were too much, going to 4.1 or 3.9 next. Very cool..

 

[Whittaker]

I have a 489 with 781 ovals 2.19/1.88 SS valves ported and polished at home, 1.75 headers, 2 1/2 in Flowmaster exhaust, 3.55 gears, 255 BFG, run a small cam comp 280 should have gone to the mid .550 lift, Edelbrock Air gap intake, and 870 Holley Street Avenger. I spent the most on a balanced rotating assembly from Eagle. Right out of Jegs but figure if I go to a solid roller and or nitrous it will be ready. I run fast bleed lifters have tons of vacuum and a hell of a lot of torque. It blew a freash tranny right after I got it going. Idles pretty nice but sounds great. I just mash the pedal and grin.

 

[Guest]

Gene,

Mine is going into my First Gen. with an M-20 and 3.31's...

I'm just worried about eating both and having to go to a 9" and a th400..

And if I gotta go th400, I'm going a built Art Carr 200-R4...

Drag say's like 10.5 at 129 if I can get her to hook with good tires without breaking anything even if it is just a sim. program...

Heck, I will be happy with a low 11 ride!!

pdq67

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[70ss496]

pdq, what heads are you running? Are you running a roller cam. I don't know what mines going to do, I'm hoping for 11's. Can't wait till the spring though. Thanks,

Matt

 

[Guest]

CC 282S solid cam and hand cleaned up new cast-iron Merlin ovals, that's all..

I built mine for midrange grunt, that's why my numbers are low. I would talk to UDHarold if you want more!!!!!!!!!

Looking back on it, a small 270 to 272 or so roller cam with a dual plane and bigger valves, (2.25"/1.94"), will make right at 600t from 2000 to almost 4500rpm so you talk about grunt!!!

pdq67

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[427L88]

PDQ, yeah, I've already got a GM marine intake ( dual flange but rect port ) 850 holley but want a 800+ cfm QJet, block, heads, springs retainers. Need a nice cam ( has to idle like a 325 396 which is what it'll look like).

In this case a hyd roller would be a good fit. I plan to shift this puppy at 5200-5500 is all, so revs aren't an issue. I'd like .600 lift and very moderate duration.

Yup, I think a 496 is an EXCELLENT idea, whether its pure street like the one I'll build, or more race, like the 10 second on its second shakedown run motor the racer had.

And certainly the reciprocating assemblies have gotten much less expensive ( which is really all I need).

And back to L78s oringal question, it is my humble UNPROFESSIONAL OPINION that a single pattern cam will produce more meat in the middle of the rpm range, than a dual pattern ( which tend to work better at higher R's.)

So if its a 6000+ motor stay dual pattern and right around 245+@.050. I plan on a sub-5500 motor, so I'm looking at a cam which should be a single pattern and something like 237@.050, .580-.600 lift, 110-112 LSA. This is in hydraulic terms. While I love solid tappets, this is a "396/325hp" and has to sound like one.i.e. quiet ex the headers. Otherwise PDQs 282s or even my UD276/84 would fit the bill.

And BTW, if I was building a 6500 rpm 496, I wouldn't use stock 3.8 rods. I'd opt for +.200 Manley Sportsmasters or something. And I'd run a cam one or two sizes up from my Ultradyne ( 243/251), and it would defintely be a solid flat tappet if not solid roller with something like 250-260@.050.

( And I sure as heck wouldn't use oval ports! )

 

[KAA]

Matt,

I tried to email you at the address in your profile but it got rejected. Do you have another address?

 

[70ss496]

KAA, I was wondering why I hadn't gotten any e-mails lately. My other e-mail address is 70ss496@charter.net.

Matt

 

[KAA]

Matt,

You've got mail....I hope.

 

[73Malibu]

Your 496 should be real nice, one note.


From what I have seen you need the longer rods when going with the 4.25" stroke

You can get a set of these, they won't put much of a dent in the budget

http://www.cnc-motorsports.com/product.asp?ProdID=4192&CtgID=3181

 

[Guest]

427L88,

I have a brand new Erson Hi Flow AH, PN E120320 that I put moly lube on and installed it in my 496, then screwed the timing set on it AND then pulled it out and put it in the box, never even wiping the moly off it b/c the "more power, Scotty" bug bit me and I went with the CC 282S!!

Brand new and there's never been a lifter on it!!!

I will sell it for $55 and eat the shipping charges if you want it??

E-mail me at home if you want it?

Heck, I will still have a brand new Clevite too so would still have a second decent torque Hy-cam for another BB.....

pdq67

PS, Timing on the Erson is 284/218(or now sold as a 220), 111/111, .542"/.542" so to me is a dandy torque cam.

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[L-78 GUY]

Thanks for all the input. When I wrote the first post I didn't own the motor....bought a 454 yesterday, disassembled it tonight and will order an Eagle assembly tomorrow [or at least VERY soon]

My builder really wants me to run the stock rods BUT I can get a complete Eagle assembly internally balanced shipped to my door for $1750. Even if I save on the Rods then I have to send my stuff out to be balanced...by the time I'm done I haven't saved much and I certainly haven't got the same quality rod.

Gonna use the 781 heads w/2.18 valves with a little hand work to unshroud. Still unsure on the cam... I emailed UDHarold so far without an answer...has he a work phone #?

Is any dual plane intake gonna be fine? And do I DARE use one of those....Holley Avenger carbs or is a double pumper the only way to fly. I drive the car around town so much that the difference between 5 MPG and 8 MPG would be Huge...What do you guys think????

 

[L-78 GUY]

I thought I'd make this post for anybody else who is going to build a 496 in the future and may be looking for UDharold recommendation on a cam. Finally today I was able to talk to Harold and he was very generous with his time helping me make a can choice and advising me on many other aspects of my combo.
Here's my specs,

1969 Body [3800 # +]
454+.250 stroke= 496''
Eagle guts
C-396 intake
781 heads 2.19/1.88 Oval OC unported
Probably 870 Street Avenger [or 850 DP]
2'' Headers
3:23/ 3:31/3:55 gears
2000 Converter
Pump gas 10.3 :1

Emphasis on street manners over et slips.
Harold recommended ...
276-284 F10 Flat tappet ground on 112LSA
276-284
243-251 @ 50
586-600 Lift
Power range 2000-6200

Horsepower expected in the high 500's. Hopefully this info may help the next fella and I'll find this post and let you know how it ran in the spring! Thank you guys for all your help as well. anybody got a nice carb for sale? cperform@aol.com