Nate SERE Posted July 19, 2014 Share Posted July 19, 2014 I have a 78 280z. It has a rebuilt L28 with dual round top su carbs. f54 block so flat top pistons w/ p79 head and cam was reground to a stage 3 equivalent less than 4,000 miles. new oil pump and water pump new alternator lightened flywheel. I have found a set of 40dcoe151 webers. Would the 40 be enough to see a major improvement or do I need 45 or 50? Quote Link to comment Share on other sites More sharing options...
gogriz91 Posted July 20, 2014 Share Posted July 20, 2014 Knowing only enough to be dangerous I would go with 45s, better to tune down too much carb than be wanting more. Quote Link to comment Share on other sites More sharing options...
310z Posted July 20, 2014 Share Posted July 20, 2014 45 would be just right. 40 will limit your breathing capacity and you will not be happy with them. Quote Link to comment Share on other sites More sharing options...
jezzza Posted July 30, 2014 Share Posted July 30, 2014 I am planning to run triple 40s on my L28. Its standard rebuilt engine Same block as yours, F54 but running N42 heads I was told by a guy who races 260z, that 40s are perfect size for L28 and should improve midrange alot. IF you were gonna run a bigger cam or porting, then you can increase to 45s.. but ultimately, both are fine for a L28 Quote Link to comment Share on other sites More sharing options...
Nate SERE Posted July 30, 2014 Author Share Posted July 30, 2014 Well I found an old l28 race motor and it has a race prepped E88 head with Nissan l4 race cam. It had cannon manifold with 40's on it. It was raced that way back in the 80's and was running on a very high compression motor. I am putting the head and 40's on my stock f54 with flat top pistons. Should get me around 10:1 compression. Quote Link to comment Share on other sites More sharing options...
brownclee Posted October 22, 2014 Share Posted October 22, 2014 great write up for installing and tuning 40dcoe carbs http://datsunzgarage.com/weber/ Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 23, 2014 Share Posted October 23, 2014 Not 50's. Not 50's; Not 50's. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted October 31, 2014 Share Posted October 31, 2014 40s with 32mm venturis (or smaller). Get it running with small carbs-that's hard enough. Quote Link to comment Share on other sites More sharing options...
AZGhost623 Posted October 31, 2014 Share Posted October 31, 2014 (edited) As others stated, no 50's. Just like any setup, your dont want to over carb your engine. Doing too big of a carb, and choking it down too small can harm performance. A 45 DCOE with 32mm chokes flows less than a 40 DCOE with the same size chokes. A 45 will breathe better at higher rpms. You didnt mention what you plan on using this setup for... Street? Race? Track? Autocross? Edited October 31, 2014 by AZGhost623 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.