well so far the parts are
454 2 bolt block converted to 4 bolt bored .60 over
SCAT Lightweight ProComp 4.25 stroke Crank
Scat Upgraded H beam 6.385 con rods
Pro Topline aluminium 360cc port modified heads
going to be using flat top pistons for about 9.75 -10 comp
Isky solid roller cam 680/680 262/272 110 LC 107 IC
Isky 1.75 steel roller rockers
Schubeck Roller X lifters
Modified Offy Dual Quad 360* med rise manifold 1 inch carb spacers
2 660 Holley center squirters.
I'd like to make at least 650HP by 6500.
what do you think?

What weight vehicle is this engine destined for?

If it's a light weight chassis (2500 lbs), it may be fine, but in anything 3000 lbs and over, I feel you have a terrible mismatch of parts.

- Heads are way too big...there more suitable for a 540+ ci max effort race engine.

- compression is way to low for the rest of the parts specified.

- never heard of that intake, but would highly recommend staying with a single carb. dual carbs just mean it's that much more difficult to dial in.

- I would NOT use those lifters. IMO, there fairly new and do not have a proven track record for reliability. Schubeck is an innovater, but also has several of his designs flop or have reliability issues. His early flat tappet ceramic lifters had problems which I believe has been resolved. His radius lifter has problems as well. This new design lifter sounds like a good idea, but until they have been out for a couple years and have hundreds of racers giving excellent feedback, I would not use them in my motor.

If you want a reliable roller lifter, then go with an Isky Red Zone or a Crower severe duty with the HIPPO option.

Other than your HP goal mentioned, what is your intended usage and goals for the whole car?

What size tire? what rear gear? what trans? what converter size & flash rpm?

Shortblock sounds fine, but I'd change the heads and induction if it were me (also change cam depending on the final compression ratio and head/induction).

interesting, well i was originaly building this engine for my 327 65 5 speed 390 rear vette. but decided i didn't want to tear up the rear and change that much stuff on an originial car. so i am finishing the engine then will find the right car. looking for an early 60s 2 door sedan. biscayne etc...,then put in the apropriate rear end and a high stall auto. depending on the weight. this will be a second toy car. for bracket racing and short hops on saturday night.
as for the engine I gave the same specs to the isky tech for a cam and he gave me those numbers. i plugged it into my DD2000 and it fell on it's face.thought i'd run it by here and listen as you guys seem to have done this a time or two. I know the intake isn't best i was going to try and make it work cause it looks so good figured i'll pick up a single plane with a big 4 barrel on it for comparasion when it goes to the dyno and if it's really hurting i'll dump it.

If your gonna bracket race and run short street cruises, then why not run more compression?

good point , i'm still half assed thinking that it's going in my vette. it's not. what comp would you suggest? I don't want to run pure race gas.

Originally posted by greg etts:
well so far the parts are
454 2 bolt block converted to 4 bolt bored .60 over
SCAT Lightweight ProComp 4.25 stroke Crank
Scat Upgraded H beam 6.385 con rods
Pro Topline aluminium 360cc port modified heads
going to be using flat top pistons for about 9.75 -10 comp
Isky solid roller cam 680/680 262/272 110 LC 107 IC
Isky 1.75 steel roller rockers
Schubeck Roller X lifters
Modified Offy Dual Quad 360* med rise manifold 1 inch carb spacers
2 660 Holley center squirters.
I'd like to make at least 650HP by 6500.
what do you think? Here's a couple of thoughts ;)
You will have no where near 10.0 with a flattop unless you mill the crap out of the heads, more like 8.5 with a zero deck.
The cam & heads would be much happier on either a big engine or a hi compression hi rpm smaller engine.
The cam would probably be ok in a 496 with less head like something in the 315 range & a true 10.5 but you I don't need that much cam for 6500 with a good head.
Did you happen to tell Isky what compression you were planning with those heads?
I find it hard to believe they would recommend that cam in an engine with less than 10.0 but would expect it if they were under the impression you were actually going to use all that head which would also lead one to the assumption you were planning some compression & some RPM ;)

What is an Isky steel roller rocker?

You will need about an 18cc dome with a 119cc head for about 10.2
A cam around 255/260 would be a bit better. 110 to 112 separation would be my choice.
Vic Jr with a 950HP or better would work very well.

If you decide on an Isky cam or lifters email me & I can probably save you a few dollars on them.

I told Isky about the compression.
we picked the rockers out of the catalouge today at the local speed shop.I wanted Comp pro magnums. like them in my SBC and he dug those isky rockers out of a catalouge. sure as hell don't see them on there web site though. guess i'll be talking to wilkeys tommorow about that. what would be a good compression point. i don't mind mixing race gas or avgas in . ( the local airport lets you pull right uip and fill up) but i don't want to run around on pure 114 race gas. guess i could turn whatever RPMs i want, i built the bottom end for it. just got some mentel block about spinning a BBC past 6500RPM. I am new to cars, spent my life with motorcycles. i apprecciate the help though
thanks
greg

why, I run around on 120 octane. Are you worried about lead polution? I like the tunnel ram deal but I have never had one, so I couldn't tell you if they're a pain or what. I need a dominator, but it would be about the same price to get another 850 dp and a tunnel ram. Why are you worried about rpm. I run mine to 7500 with no concern whatsoever, but my valvetrain geometry is perfect and my lash is perfect(I use a fishscale on the feeler guage to get the lash perfect-companion cylinder method of valve adjustment).

If you stick with the pro heads, go with the 320's, and thats still a little unnecessarily large. Not too big, but a little if your rpm limit is 6500. No reason to run such a gigantic camshaft or heads. Im not sure what you plan on spending, but I would also consider some brodix, AFR or canfield heads as well. Heck, a properly ported factory cast good big block head can do what you want it to do. Something in the 290-310cc port size would be good. AFR sells great 305cc head. Also, Canfield sells a good 310cc head thats priced better than the AFR, and dont forget brodix. Theve got a 294cc race rite head(as well as others) thats up your alley as well, but I cant comment on pricing.

Two four barrels are cool, but a single carb, single plane intake is a better choice all around. Less tuning, better power, and more streetability. I agree that something like a 950hp(or something comparable) and a large single plane with a cam like wolfplace said(255/260) is the way to go. Dont worry about having to run race fuel. Especially if your with a camshaft of that size and keeping the compression between 10-10.5:1. Thats not optimum compression for most cams of that size, but it is enough and will allow for pump fuel with the aluminum head(it would work with an iron head as well as long as you spec the proper camshaft). Bigger isnt always better. Although that would be one rad motor you initially planned(assuming you stepped up the static comp enough to work with that cam), you wouldnt be getting what you payed for unless you built the bottom end and valvetrain to handle some serious rpm, cause a top end like that should be pushed a good bit more than 6500rpm in a 454. If you never spin over that rpm, you will have one fancy cam and heads that will never get the chance to show you what they can do. As far as the horsepower goal you have, dont worry bout missing that goal by stepping down a bit. With the milder stuff(that still isnt mild really) you can meet your goals. Good luck.

well unfourtuatley, or fortuatly. everything but the cam and pistons is already purchesed. the block is getting bored for splayed maincaps as i speak, (type ?) . I wanted the bottom end as strong as i could in case i went nitrous or blower later. so maybe i should just set a new target for the RPMs and get the right compression to make use of the components i have. like i said.i'm not rally worried about street ability . I'm going to build/design the car around the engine at this point. it's goping in some kinda ratty project car where the money is going into the drive train. allready got a purdy old 65 vette

Greg, Those heads are just too big on that small of an engine, however you mentioned the magic word "BLOWER" on your last relpy. You also mentioned that you haven't bought the cam or pistons either, well why not build a blown motor. It's big bucks, but a blower would help mask the oversized ports. Oh, and that 650 HP range you were figuring on, well that's out the window :D With the right blower, cam, and pistons, the 468 could be in the 1000 HP range.

excellent thinking, after reading whatyou guys where syaing last night i went to summit racing and ordered an 8 71 weiand Blower kit. I figure I will cancel the schubecks lifters and fancy cam.I'll sell the manifold and 660s on ebay. I'll just buy a nice solid flat tappet cam. hell thats half the money right there. I like the way you think.
Thanks
guys
Greg

are you sure you need the 8-71? find a big shoebox for that thing to go in and you will have a cool az car.

Greg where in Mesa are you. Im in Gilbert, If you need any help let me know.

thanks man, i live right of Horne and McKellips. I'mwaiting for parts to arrive but will need (obviously)all the help i can get.
thanks
greg

I run a very similar combo,
Scat forged bottom
TRUE 10.5:1 Compression
GM 990 315CC rect heads
950 HP w/ Vic jr.
Lunati Solid roller 260/268@.050 .685/.685 lift 108 102
etc, etc,

Havent got it to the track yet, BUT, Its a very snappy engine and will run up to 7k REALLY quick...

I can imagine with more head and less compression, it would be someone lacking in the low end. tongue.gif

well i canceled the schubeck lifters. was planning on going to a flat tappet but the guy at the speed shop convinced me to stay with a roller. just going all Isky for it.This should be an interesting engine.

Greg,
When youre ready drop me an email
helopilot1967@yahoo.com

Ok going off the comments I received here and the corvette forum I have made a small correction or two to my collection of parts now it is

454 2 bolt block converted to 4 bolt bored .60 over
SCAT Lightweight ProComp 4.25 stroke Crank
Scat Upgraded H beam 6.385 con rods
Pro Topline aluminum 360cc port modified heads
going to be using flat top pistons for about 7.5-8 comp
Isky solid roller cam 640/650 304/318 252(?)/264 112 LSA
Isky 1..75 roller rockers
Isky pushrods
Isky springs
Isky Red zone lifters
weiand 871 blower Kit 12% under drive
Only thing I haven’t ordered/received are the pistons
I'd like to make at least 700HP by 6500.
What do you think?
and thanks for the advice, it will cost a little more but i would have been unhappy with a expensive dog.
greg