LS7 build started
Thread Starter
Drifting
Joined: Nov 2005
Posts: 1,361
Likes: 0
From: Downriver Mi.
LS7 build started
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
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
Last edited by MR NICE; Jun 10, 2012 at 11:24 AM.
Race Director
Joined: May 2004
Posts: 11,920
Likes: 2
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
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
Instructor
Joined: Oct 2007
Posts: 167
Likes: 1
From: Escondido CA
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.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
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.
Instructor
Joined: Oct 2007
Posts: 167
Likes: 1
From: Escondido CA
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.
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Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
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.
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
,dont want to buy one then find out it wont work?
Instructor
Joined: Oct 2007
Posts: 167
Likes: 1
From: Escondido CA
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.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
454/ls-7
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...........
....
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
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...
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...
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
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.
Drifting
Joined: Jul 2009
Posts: 1,531
Likes: 13
From: Dallas-Fort Worth TX
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.
Burning Brakes
Joined: Mar 2005
Posts: 800
Likes: 2
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.
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
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.
Instructor
Joined: Dec 2011
Posts: 142
Likes: 0
From: Tucson Az
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
Last edited by nonracer; Jun 15, 2012 at 09:33 AM.