MR NICE

Been collecting parts for a while ,now the fun,dropped the block off at the machine shop a couple days ago,here is what i have so far,

445 4 bolt block


Forged ls7 pistons

Forged crank

7/16 rods

12.50 to1 appox, heads and block decked .010?

990 rec port heads comp valve job(stock)

1050 dom carb to be converted to e-85

454 R intake

hooker super comps 2 1/8 x 3.5

comp solid roller lifters

fluid damper with sfi flex plate

8" coan 4500-5000 stall

400 turbo

3.73 rear end till i spit it out,then 4.11-4.56

looking for advise on a sr cam that will clear the stock ls7 high dome pistons,want it to be mean & nasty, scare women and children will be driven to the store and back

Summerfun

Careful on that LS7....you have to mix gas on those.

If you get lazy, you melt three pistons....ask me how I know

That's why I went 540....liked the LS7 power, but needed lower compression

Then wanted more...hence the Vortech carb blown through unit

MR NICE

running e-85 is my plan,got to do my part to be green and help the farmers

badrad

How high are you willing to spin it? Realistically it's going to want to spin.

MR NICE

it will be balanced 7000 to 7500 ?

badrad

That should be fun. You'll have to check piston to valve clearance, every cam is different. A lower lift but really long duration can still kiss pistons with valves. Are your heads ported? Stock heads will want a lot more exhaust duration and a slightly wider LSA will help to scavenge the cylinder at high RPM.

Vette5.5

Kinda curious what's LS7 about your build, as have a factory C6 ZO6, and it's LS7 is way different than what you're doing. 6 bolt main aluminum block, titanium rods, hypereutectic pistons, and heads that flow like crazy. Is there another LS7 I'm not familiar with, as can't say I've heard of it.

badrad

The 454 LS-7 was a crate engine that was a full race trimmed big block. Had 12.5:1 compressio, big port heads and a huge solid lifter cam.

Vette5.5

Thanks for clearing things up, as obvious I was missing something here. Never even knew this engine ever existed, but just learned something new today. Sounds like one heck of build you're doing "Mister Nice". Keep us informed of the progress.

HamadUP

It also found its way to one '70 Corvette, but the GMs decided to pull the plug and destroy that car.

MR NICE

need a idea on a solid roller cam that wont hit,dont want to buy one then find out it wont work?

badrad

No one can guarantee this, every cam is different. Unless you stick to the stock spec cam you need to measure it, the valve reliefs in the stock pistons aren't very deep. The stock L88 cam hit in my 427. Most guys get their pistons flycut. You're building something other than a DD, you need to measure everything during assembly.

MR NICE

i was hopeing someone has ran the same setup with a solid roller cam would know what might clear?or else u buy a cam and hope?dont want to cut on the pistons.

Ironcross

I have a real 454/LS-7 and installed it in one of my Camaros.....its basically similar to a L-88 and was considered for the 1970 Vettes....what ever the reason it was not produced as a factory install is possibly by the 'tree huggers and greenies' getting into the act and minds of the GM`s brass. ....Over the counter long block engine.....I paid 2600.00 for it in 1988.....first run was 12.20 sliding all over, reduced tire pressure and worked it into the 11`s down to 11.42 at Detroit Dragway and was told to slow it down or go home, no cage....now its a great street racer and the dragway is gone...........

ajrothm

You're going to have to check piston to valve clearance on ANY cam you run... You are going to have to degree the cam in and probably play around with different advance degree numbers to help the piston to valve clearance.

A big dome piston doesn't leave much room for error for piston to valve clearance.

I would contact www.straubtechnologies.com and have Chris custom spec you a cam for your build. Get it right the first time.

Good luck keeping head gaskets in it at 12.5 to 1... E85 or not...

HamadUP

With all the new techs. in casting cylinder heads and grinding cams, its hard to be forced to use a 12.5 CR in order to get a mega horse power numbers, I got a 11 CR in my '70 Z28 and its already causing me a lot of headache trying to avoid detonations. If I would build any new HP motor, I would stick to 10 CR or lower.

Rebelrob

I resurrected an original LS7 that was sitting in the corner for many years.
The compression was de-tuned and ended up with a nice set of aftermarket high flow heads that are more suitable. The original heads apparently did not flow were a damn until you were above 4500 rpm's.
I took some pics of the engine suffix stamped on the block before I had it decked/machined.

Good luck,
Keep us updated.

eatmydst1234

I have an LS7 in my '69 chevelle, stock cam with roller rockers. Been thinking about converting to E85, as race gas has gotten a little too expensive. it has brought that car down the 1/4 in 11.85 on street tires through a muncie M-22. The engine is routinely spun up to 7200rpm on the strip and it takes no time at all to get there.

69 Chevy

Two thumbs way, way up! It does my heart good to see someone on this forum who runs a rat motor the way they were intended. Yet there's a ginormous amount of mouse motor folks who post here that think 5500 rpms is outrageous.

nonracer

Im not telling you NOT to check piston to valve clearance but I bought an LS7 from GM had the heads surfaced,decked the block,used all the stock parts like you have and put in an Ultradyne cam ( now Bullet Cams). I dont remember what the actual clearance was but it had plenty I degreed the cam to the spec card and also ran it 4* advanced.
I dont know the part # but here are the specs
264*@.050 int
268*@.050exh
.670 lift int/exh
110* lobe
My combo made 625 peak hp @ 6600 on an engine dyno
I had no issues with head gaskets using the stock head bolts and FelPro HP gaskets but I always ran race fuel
This was in a 3400lb camaro with 10" tire leaf springs and slapper bars I ran a 4200 ATI converter with a TH350 and 4:10 gear it ran high 10.30's @ 130