Tall Deck blocks and FI
Thread Starter
Registered User
Joined: Jan 2022
Posts: 3
Likes: 0
From: Napanee ON
Tall Deck blocks and FI For a pump gas 1400hp FI motor, everyone on here seems to go 408" or 427" or maybe 440". Doing the math it's only around $100 extra in a short block to buy a tall deck Dart block and run a 468" or 480". I'm all new to the LS platform, Last build was a roots 540" BBC, and for BBC the 540" seems to be a well used size with a decent rod stroke ratio of 1.50:1 and plenty of piston to fit a ring set. I just did what everyone else was doing. A 4.250" crank in a tall deck skirted LS Dart block doesn't need clearancing, gives even better rod stroke ratio than my old 540" and plenty of room for a decent piston. Seems an obvious choice so what am I missing? School this LS newbie.
IMO aftermarket blocks are always a better option then the standard production blocks and to reach big cubes on those require a re-sleeve and by the time you invest into that you could have had an aftermarket block. If you have the room then go tall deck, it allows to build even more cubic inches reliably and run NOS or FI. Who wouldn't want 500ci of LS motor under the hood.
You need to specify what FI. With a roots/screw blower or centrifugal supercharger I would go bigger as you outline. However, I think a lot of the guys you mention who have the 388-427" motors have them because they're turbo cars. A 427 is more than enough to spool any large frame turbo and anything more than that starts limiting you on the turbine side with back pressure when you get into big power numbers. Hell there are guys out there spooling 106mm turbos on 5.3 motors. Quite simply on a turbo motor there is no need for more cubes.
Thread Starter
Registered User
Joined: Jan 2022
Posts: 3
Likes: 0
From: Napanee ON
I'm running a gear drive procharger. From what you're all saying for pump gas the extra cubes at not much cost might be beneficial. I'll see what the parts bill looks like for an off the shelf tall deck vs maybe a 427 short block and go from there.
Plus there's something awesome about a 500" LS with an F3-134 or something hanging off the front.
IMO aftermarket blocks are always a better option then the standard production blocks and to reach big cubes on those require a re-sleeve and by the time you invest into that you could have had an aftermarket block. If you have the room then go tall deck, it allows to build even more cubic inches reliably and run NOS or FI. Who wouldn't want 500ci of LS motor under the hood.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'
Brett Foote
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Its about longevity...... Cylinder wall thickness, the thicker the stronger. The longer the stroke or longer the rod the less reliable it is, more leverage to bend the rod and more side loading on the cylinder walls.
481X, BBC, Hemi, all totally different layouts and geometry compared to an LS platform. Comparing a $8,000 short block to a 20,000 shortblock.
481X, BBC, Hemi, all totally different layouts and geometry compared to an LS platform. Comparing a $8,000 short block to a 20,000 shortblock.
Thread Starter
Registered User
Joined: Jan 2022
Posts: 3
Likes: 0
From: Napanee ON
A tall deck makes a beautiful high power, durable 4-in stroke engine
Paired with a 6.350 rod you get it an excellent compression height with plenty of room for a super stout piston
And the piston is completely contained in the bore at bottom dead center
Paired with a 6.350 rod you get it an excellent compression height with plenty of room for a super stout piston
And the piston is completely contained in the bore at bottom dead center
There are many other builders out there who also build well engineered, reliable high powered combinations that don't charge for the name.
Bryan with LME or Erik Koenig of HPR are other places you'd expect to pay more to have an engine built and a good reputation will generally merit an increase in price. There's also some crooked SOB's in this line of work too that'll steal your parts and say you have something that you don't which is why there's the saying "You get what you pay for." First engine I ever built was an LSX427 and a special thank you to Joseph Potak for his book "How to Build and Modify GM-LS Series Engines" and to Texas Speed and LME for the parts and service.
TECH Fanatic
Joined: Feb 2015
Posts: 1,080
Likes: 178