bonkas Posted October 17, 2017 Share Posted October 17, 2017 Hey Guys, Have run into another issue which I am having trouble finding a clear answer for. I am looking to run a pair of Dellorto DHLA 45's on my 4g63. I am at the point where I need to make a decision on Intake Port Size, the valves have been enlarged so I need to also increase the small port for more flow. The carbs I have are 45's, One which is in need of repair and they both need a rebuild and misc parts replaced. The real question is do I run 45's with a smaller choke size (34mm or so, 36-38mm for peak power around 6000rpm ish) or do I sell these carbs and pick up the 40's which are on trademe at the moment which have been rebuilt and tunes for a 1600, I will just need to adjust the chokes etc to suit the larger capacity engine. Do I port match to 40mm and run the 45's anyway or is this a poor thing to do?, port match to 45mm with the 45mm carbs or get the 40mm carbs and go to a 40mm port. The engine is having compression increased to around 10.5:1, port and polished head (bar intake), 2mm larger intake and 1.5mm larger exhaust valves. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted October 22, 2017 Share Posted October 22, 2017 The answer is simple - throttle bodies. But if you must stay with carbs, the 45's should be fine. As for porting, it's hard to say without looking at your manifold and going exploring with a die grinder. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted October 23, 2017 Share Posted October 23, 2017 I would say 45's for a 2 litre engine. Quote Link to comment Share on other sites More sharing options...
bonkas Posted October 23, 2017 Author Share Posted October 23, 2017 Chur guys, Have made the decision to continue onto the 45 path. Increasing intake port size to 41.5mm, will need to fabricate a manifold to taper down to this size. 1 Quote Link to comment Share on other sites More sharing options...
Truenotch Posted October 24, 2017 Share Posted October 24, 2017 That should work well. A nice tapered runner is usually a good thing. Quote Link to comment Share on other sites More sharing options...
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