Few questions

Parts I have
454 2 bolt block 60 over
3.76 forged crank (aftermarket)
6.385” rods Scat H beam with ARP 2000 bolts
Wisco pistons:
1.520" Compression Height/+48.4cc/+.700" Dome Rise
Compression about 12.21:1
Copper head gasket .040
Victor Jr intake
Dart iron eagle heads (308) 119cc int 2.25 ex 1.88
28” tall tire
th400 trans

Need help with solid roller cam selection, and rear gears going in a stripped out, caged 71 nova. Looking for mid 10.

Do I need to "O" ring the block?

Will a studded 2 bolt block hold up? Or should I get some 4 bolt main caps?


1050 Dominator good carb choice?


Need a good oil pump, that doesn’t mind spinning over 7k

The block is fine. If you haven't line honed it yet I would get main studs just for insurance but you don't have to. No O-rings you don't need them. I would talk to the cam people about a cam they should now they build them. I don't like dominators on anything that isn't real serious. Try to get more tire under the car it will help quite a bit.

Something flowing 850-900 cfm is all it'll need. I wouldnt 'Dominate' it. HP950 should be good for your 7200 peak rpm. Cam choice should be something like 255/263@.050 on a 108lsa, i.e. not huge other than the .700 lift ( not for street, right?), installed advanced with a shift point at around 7-7200-ish.

Todd Geisel will have a good cam choice which ran mint in his 414, simply add a few degrees. He is SOLIDLY in the 10s. He'll be better able to 'guess' the cam size given the difference in head ( 280cc 781s? vs your 305cc ). I know you'll want the cam phased well advanced if its an assymetrical grind like a new Lunati. And you'll wnat to keep it on the smaller side. Keeps the port velocites high through the bigger heads.

If you do the math a 4.33/4.56 gearset would be about right, with a 4500+ stall. Maybe 4.56s.

I wouldn't think twice about a 2 bolt studded deal as long as the saddles are spot on. However, if this is a high dollar build, the $ savings of a 2 bolt block vs total build cost starts to look irrational. Can't comment on the longer rods for this app. Have only used true L88 rods at 7300 rpms consistently without failure.

Best oil pump = M77 STD with heavier pressure relief spring inserted, anti-cavitation troughs ball milled ( not critical with modern oils I'm told), and gear end play checked and reset if need be. I.e., a $22 pump with an hour of blueprinting OR the $65 blueprinted version. The $65 version can be had from Moroso, or GMPP ( L88/Ls7). No HV wanted or required here unless you'll be idling it ALLOT on the street with the SR cam or the engine is built loose to L88 specs ( 6 thou skirt, 3 thou rod, 25 thou rod side). You dont need or WANT a HV pump at 7200. Alls it does is waste power and blow the oil out any marginal seal. Does create a beautiful oily haze inside the enigne though which can be seen soon after a hard run by pulling the oil cap off a valve cover.

Beautiful swirling oil vapor. good for the valves/springs I suppose. ;)

GOOD LUCK! Run down a search on 10secBu and get some of Todd's info. I should think a cam like his with a few more degrees would be fine give the bigger heads and extra 30 cubes. You'll be using more gear and rpm I think. COnversely, if you look at the batch of solid 10 sec performers here, you migth think that 255 is a bit long on duration!

427L88, I do have a set of the 781 heads bone stock. The dart heads I have are bare. They would need some machine work and assembly. I wonder if I would benifit any putting the money into the 781 heads, I could have the bigger valves put in and some port and polish work.

I would not use copper head gaskets unless you really like fighting water leaks.

2 bolt block with ARP studs will be plenty strong. No need to convert to 4 bolt.

With those heads, expect the power band to be higher than an oval port setup. I ran a 427/414 pump gas combination with 781 large oval head and 10.5 to 1 compression on pump gas. I shifted at 6800 rpm and it saw 7100 rpm in the lights. Your gonna be a good couple hundred rpm higher to make decent power. The larger heads will also need more converter stall. Mine flashed to 5500-5600 rpm on an 8" ATI.

With a 28" tall tire, I'd go with a 4.10 gear...4.56 max. 1/8th or 1/4 mile?

71 Nova, do whatever he says to do! Todd, I dont remember the specs offhand on that old cam of yours. Also was figuring a bit higher rpm with the 4.33 gearset. THNX for catching my reference to you.

Hey Gene graemlins/waving.gif

The original cam was the box stock XR286 which had 248/254 @ .050, 286/292 gross, .653/.660 lift, 110 lsa installed on a 106 icl. The replacement custom version had all the same specs except the lsa was ground on a 107 with no advance ground in (107 icl)(also ground on a billet core).

Ah, don't listen to me...made too many mistakes in the past with combinations and I'm sure to make more in the future redface.gif . I just got some good help from you know who which made the combination work really well for what it was. I certainly wouldn't do a destroked aluminum rod deal like that again, but it ran decent in spite of itself.

The most important thing to keep in mind is that the combination has to work together and that is more important than any one "trick" part, especially if that part doesn't compliment the rest of the package.

For his combination, I think the XR292 or maybe the 288AR circle track grinds might be baseline specs to build from in looking for a grind.

His dilema right now is to decide upon an intended power band range and max redline. Once that's decided, the head choice, cam selection, gear selection as well as converter stall all have to be geared around that max power/max rpm goal. Iron Eagle 308's for higher rpm (probably close to 7500 rpm) or ovals for milder rpm (6500-7000 rpm). Many ways to accomplish the same ET/mph goal, just have to sit down and decide on your goals and also how much maitenence your willing to perform...more rpm = more maintence, more potential for parts failure.

Man, mainteneance even for a high stepping solid lifter street engine!

I think Todd hits on the essence of engine building or systems design. Every component needs to be matched to the inteded powerband, i.e., rpm band. Gearing/stall is then mathced to the engine. That's what makes a solid combination, not whether you use oval or rectal, etc. I would only, btw, use the rectals if you don;t mind buzzing this thing up to 7200 or so ( shift point I mean, 7400 peak rpm)those rctals will not hold you back. IF you should decide to keep rpms a bit more limited, the ovals should 60' much better, and therefore ET better even if your top mph is off 1-2 mph.

Thanks guys, I hear what your saying. This will be 1/4 mile runs.
I think I will go with the 781 heads. The 7500rpm is a bit scary. I have never spun a motor that high before.

If I can get into the 10’s, that should be plenty fast for me.

Should I go with a shaft type rocker set up? Or roller rockers with a stud girdle?

Cam specs I was looking at. Solid flat tappet

Part Number 11-605-5
Engine 1965-1996 Chevrolet
396ci-454ci
8cyl.
Grind Number CB 310B-8
Description

--------------------------------------------------------------------------------

Intake Exhaust
Valve Adjustment 0.028 0.03
Gross Valve Lift 0.638 0.631
Duration At 0.02 Tappet Lift 310 314

--------------------------------------------------------------------------------

Valve Timing At 0.02
Open Close
Intake 47 83
Exhaust 85 49

--------------------------------------------------------------------------------

These Specs Are For The Cam Installed At 108 Intake CL
Intake Exhaust
Duration At 0.05 270 276
Lobe Lift 0.375 0.371
Lobe Separation 108

71 Nova, Looks to me you getting some good advice re cam selection, FWIW my 427 10.3cr engine very similar to yours( Brodix Ovals) and UD Harold spec'd out this Solid Roller cam (285/295 245/255 @.050 630 lift ) ground on a 110 LSA installed 106 for some street use but suggested 108 LSA for track use ...... this back in the dying days of Ultradyne believe he has new version under Lunati ( yes taking me forever to complete this car :( .... I'm back on the Dyno early Feb with this motor with Holley 950hp and some carb spacers and collector testing
I agree you may want to rethink your head gasket selection you will have no problem going 10's in a light Nova even if you lower compression to run pump gas .... but you may need more cam = more rpm !! if you stick to 12 .1 cr
Yes stud girdle if you rpm motor try and budget for a Solid Roller , you wont be disapointed

No expert, just some more Info for you , just an old guy trying to have fun with his old car
Bill

71 NOVA,

Here's the spec's on my old Camaro that ran at the strip only the last 5-6 years that I had it. Hopefully it will give you a reference point.

If your car is as "stripped" down as you say, you may not have to get too radical to get into the 10's and if it is fairly light, advancing the cam probably won't be neccessary.

-68 Camaro 3300lbs w/driver.
-.060 over 427 2bolt mains, factory main caps were soooo close it didn't need to be line bored.
-12.5 pistons netted about 11.25 comp. with the 049 heads that had 2.19 / 1.88 valves(unported).
-Factory 3/8(yes 3/8")truck rods(bushed and resized).
-Standard volume oil pump(melling)40psi @ idle / 75psi @ trap RPM.
-Isky custom cam, solid flat tappet, 254°/258°@.050, 288°adv, .620 lift on both 108°LSA/ .018 lash/installed straight up(made tons of power with the faster ramp speeds).
-1.8 Isky roller rockers(a little heavy IMO, but bullet proof)
-RPM intake
-HP 950 / Bolted it on and ran the best with all of the factory settings.
-HEI dist. w/MSD 6AL
-2" Hookers
-TH400 manual shift
-Ford 9" w/ladder bars
-4.86 gears(wanted to try 4.56's since my car went 1.45 60 ft's, but never got around to it. I always wondered if it would have made a difference).
-29.5 Hoosier stiffs
-All my accesories were electric though

At 3000' DA the car would run 10.80's all day long(best of a 10.71). Launched @ 3800 on the chip/Flashed to 5300, Shifted @ 6200RPM, Traps @ 7300RPM @ about 122MPH. Tore the engine down @ 300 passes and replaced the rings,bearings,springs, and the rest checked out fine.

You could probably put that same approx. size roller in and make more power and even put it in straight up(once again, if your car is light and "stripped")

That 2bolt will be fine, and so will those heads. Remember that this will be internally balanced and it is more forgiving than an external like a 454. If your pistons and rods aren't too heavy, that's an added bonus.

I believe without a shadow of a doubt that for any average "fast" car the HP 950 will out-perform the Dominator on any given day. My uncles car made only 15HP better on the dyno with the Dominator and it made 790HP(very large bore 427, not really, but thats the closest I can describe)479CI.

Do your research and you'll know what to get.

Rob

427s dont have much problem living at 7000rpms,BUT everything has to be 110% correct,esp the valve train. To do the 781s correctly will set you back around $700.

In a 3900 lbs stock Chevelle,its one thing. In a 3000 lbs ride,I really think you're splitting hairs. My recommendation to advance the cam applies tolarger ports. Velocity in the small ports will be adequate and 0 or +2 is fine. +6 on rects,imho. Don't worry, the cam might run out, but the heads won't so upper rpm is not limited much by the advanced phasing ..

Build an L88 clone motor with a modern SR cam and you should see 10s. Many have before.

Will an RPM intake be better than a victor jr?

With those heads your going to have to spin that thing to 7500-8000, which really isn't a problem for a 427, however; I would recomend converting to a 4 bolt main because cap walk will be an issue at 8000 rpm.