402 vs 427?
Thread Starter
Staging Lane
Joined: Nov 2005
Posts: 59
Likes: 0
402 vs 427? If you were to build a street car, to be used for occassional "casual" circuit racing, would you go with the 402 or 427? The car in question is an '04 Holden Monaro (it came with LS1 from the factory but currently has heads/cam).
What characteristics between 402 and 427 do you think would be suited (or not) to circuit racing? Maybe there is something in between 402 I should be considering as well.
Would the application of revs/power be much the same with these two motors (just bigger power with bigger cubes?) or would I be sacraficing something with the larger motor i should know about? Same goes for street drivability I guess... would the 427 = just bigger grin factor? or do I sacrafice something i may wish to retain with the smaller motor (apart from fuel economy).
What characteristics between 402 and 427 do you think would be suited (or not) to circuit racing? Maybe there is something in between 402 I should be considering as well.
Would the application of revs/power be much the same with these two motors (just bigger power with bigger cubes?) or would I be sacraficing something with the larger motor i should know about? Same goes for street drivability I guess... would the 427 = just bigger grin factor? or do I sacrafice something i may wish to retain with the smaller motor (apart from fuel economy).
If you have the $$ build a dry sump factory LS7. The LS7 intake flows the most out of any production/FAST intake and supports higher RPM breathing with large factory 2.2" lightweight titanium valves in the heads. They help these small block heads flow like big block style heads plus the port design is awesome for all around flow/velocity. Also with dry sump oiling you will have no oil control problems which F-bodies and even Vettes sometimes suffer from on the road course (ie fried bearings)
Originally Posted by forrestd
If you were to build a street car, to be used for occassional "casual" circuit racing, would you go with the 402 or 427? The car in question is an '04 Holden Monaro (it came with LS1 from the factory but currently has heads/cam).
What characteristics between 402 and 427 do you think would be suited (or not) to circuit racing? Maybe there is something in between 402 I should be considering as well.
Would the application of revs/power be much the same with these two motors (just bigger power with bigger cubes?) or would I be sacraficing something with the larger motor i should know about? Same goes for street drivability I guess... would the 427 = just bigger grin factor? or do I sacrafice something i may wish to retain with the smaller motor (apart from fuel economy).
What characteristics between 402 and 427 do you think would be suited (or not) to circuit racing? Maybe there is something in between 402 I should be considering as well.
Would the application of revs/power be much the same with these two motors (just bigger power with bigger cubes?) or would I be sacraficing something with the larger motor i should know about? Same goes for street drivability I guess... would the 427 = just bigger grin factor? or do I sacrafice something i may wish to retain with the smaller motor (apart from fuel economy).
Thread Starter
Staging Lane
Joined: Nov 2005
Posts: 59
Likes: 0
thanks for the comments; it sounds like the 402 might be the way to go, with the 427 yielding only slightly more on the straights, yet costing significantly more. What sort of power are the 402's making in the states?
Trending Topics
TECH Apprentice
Joined: Feb 2005
Posts: 395
Likes: 0
Originally Posted by forrestd
thanks for the comments; it sounds like the 402 might be the way to go, with the 427 yielding only slightly more on the straights, yet costing significantly more. What sort of power are the 402's making in the states?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
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!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Staging Lane
Joined: Nov 2005
Posts: 59
Likes: 0
Been a while but here's an update. We ended up putting together a 438ci motor (using LS7 block) with L92 heads and L76 intake. I was initially worried if would be "lazy" and not spin up as quick as my 346, or even a 402.
How wrong was I? The thing revs up QUICKER than my old head and cam 346 LS1. It dyno'd at about 505rwhp, however i believe aussie dynos may read lower than US ones (if that matters, doubt it).
At the srtrip we've run 11.0@125mph on 15" ET Street radials; it should be good for a 10 i suppose.
Here is some video of some circuit / road course action from yesterday:
http://www.youtube.com/watch?v=R4NXBTIbVpk
How wrong was I? The thing revs up QUICKER than my old head and cam 346 LS1. It dyno'd at about 505rwhp, however i believe aussie dynos may read lower than US ones (if that matters, doubt it).
At the srtrip we've run 11.0@125mph on 15" ET Street radials; it should be good for a 10 i suppose.
Here is some video of some circuit / road course action from yesterday:
http://www.youtube.com/watch?v=R4NXBTIbVpk
Been a while but here's an update. We ended up putting together a 438ci motor (using LS7 block) with L92 heads and L76 intake. I was initially worried if would be "lazy" and not spin up as quick as my 346, or even a 402.
How wrong was I? The thing revs up QUICKER than my old head and cam 346 LS1. It dyno'd at about 505rwhp, however i believe aussie dynos may read lower than US ones (if that matters, doubt it).
At the srtrip we've run 11.0@125mph on 15" ET Street radials; it should be good for a 10 i suppose.
Here is some video of some circuit / road course action from yesterday:
http://www.youtube.com/watch?v=R4NXBTIbVpk
How wrong was I? The thing revs up QUICKER than my old head and cam 346 LS1. It dyno'd at about 505rwhp, however i believe aussie dynos may read lower than US ones (if that matters, doubt it).
At the srtrip we've run 11.0@125mph on 15" ET Street radials; it should be good for a 10 i suppose.
Here is some video of some circuit / road course action from yesterday:
http://www.youtube.com/watch?v=R4NXBTIbVpk
Thread Starter
Staging Lane
Joined: Nov 2005
Posts: 59
Likes: 0
Funny you should mention that, i've ordered a set of LS7 heads from Texas Speed, however they seem to have trouble devilering the product for some reason.
WHY do I keep hearing negative things about TSP lately? 
I got a quote from them not to long ago, but lately i've really been considering going a different route with a builder.
I got a quote from them not to long ago, but lately i've really been considering going a different route with a builder. 
Thread Starter
Staging Lane
Joined: Nov 2005
Posts: 59
Likes: 0
Sorry i was kind of digging up an old thread.
We ended up doing an LS7 438ci motor, which is the car in the video.
11 Second Club
Joined: May 2007
Posts: 226
Likes: 1
From: Sydney
cheers