Head Work for a Turbo Engine
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Banned
Joined: Jul 2010
Posts: 853
Likes: 19
From: Melbourne
Head Work for a Turbo Engine
Okay, So I have a spare set of stock Evo heads in the shed and figure that it might be a good idea to have them worked a little bit and then bolt them onto the turbo engine.
Now I know that all the work you do porting heads for a normally aspirated engine is designed to allow air/fuel to be drawn into the engine in high volume and speed. BUT what about turbo setups??? I mean; I have 5lbs of boost pushing the air/fuel mix into the engine, so does the same theory apply?
In my mind the design would have to be different; but then again my mind is a strange place at times.
Cheers
Now I know that all the work you do porting heads for a normally aspirated engine is designed to allow air/fuel to be drawn into the engine in high volume and speed. BUT what about turbo setups??? I mean; I have 5lbs of boost pushing the air/fuel mix into the engine, so does the same theory apply?
In my mind the design would have to be different; but then again my mind is a strange place at times.
Cheers
Tourer
Joined: Oct 2012
Posts: 302
Likes: 8
From: Maryland
Now I know that all the work you do porting heads for a normally aspirated engine is designed to allow air/fuel to be drawn into the engine in high volume and speed. BUT what about turbo setups??? I mean; I have 5lbs of boost pushing the air/fuel mix into the engine, so does the same theory apply?
Cheers
Cheers
Thread Starter
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Banned
Joined: Jul 2010
Posts: 853
Likes: 19
From: Melbourne
Its a daily rider (even during winter).
Issues such as boost lag are not a problem with the setup...It pretty much starts makes boost from idle.
I suppose my question is: Are 'normally' worked heads okay to run or are there extra considerations that you can do specific to a turbo/blower setup.
Issues such as boost lag are not a problem with the setup...It pretty much starts makes boost from idle.
I suppose my question is: Are 'normally' worked heads okay to run or are there extra considerations that you can do specific to a turbo/blower setup.
6th Gear
Joined: Oct 2015
Posts: 14
Likes: 0
From: Home off the Vikings
Its a daily rider (even during winter).
Issues such as boost lag are not a problem with the setup...It pretty much starts makes boost from idle.
I suppose my question is: Are 'normally' worked heads okay to run or are there extra considerations that you can do specific to a turbo/blower setup.
Issues such as boost lag are not a problem with the setup...It pretty much starts makes boost from idle.
I suppose my question is: Are 'normally' worked heads okay to run or are there extra considerations that you can do specific to a turbo/blower setup.
I hawe also ben wondering about this Things, because i am about to do som e work on my own heads. The first engine Builder i asked here in Norway said : Be wery careful With opening the ports, because you wil lose Your torq before the turbo start to build preashure. The other engine Builder said: you should og With bigger valves. I am thinking that on my engine With 117" and a smaal turbo, SE 255 cam, low end torq should not be probl anyway. (sorry for my bad English)
Road Captain
Joined: Mar 2008
Posts: 697
Likes: 5
From: NE, FL
Some folks believe, and maybe rightly so, that extensive head work for FI isn't necessary because of the air being forced into the pump. I wasn't one of those guys, and maybe it was a waste of money, but I sent my heads to Dan Baisly for work. He knew it was a turbo motor but I can ask him what he did if you have interest.
Seasoned HDF Member
Joined: Apr 2013
Posts: 32,851
Likes: 17,888
From: Newcastle, OK
I would think at some point there is such a thing as too much volume when you`re talking about boost, whether it`s turbo or supercharged. Too much compression comes to mind and the possibility of blowing the engine. This needs to be thought out carefully.
Thread Starter
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Banned
Joined: Jul 2010
Posts: 853
Likes: 19
From: Melbourne
Your sort of right.... Big volume on the heads/ports/valves would work a real treat once boost has come on, BUT it would run like a dog until she had a head of steam up. I suppose you end up sacrificing bottom end power for mid to top.
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Road Master
Joined: Feb 2007
Posts: 1,161
Likes: 39
From: LOST WAGES
I would be more concerned about camshaft profiles than the heads. The gains from headwork on a forced induction engine are minimal, while camshaft selections make more of a difference.
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Thread Starter
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Banned
Joined: Jul 2010
Posts: 853
Likes: 19
From: Melbourne
+1 there....I run an Andrews EV31 Blower Cam. I did run a standard EV35 but the power came on too fast and the bike was mean to ride; with the EV31 power is more balanced accross the rpm range as well.
Road Master
Joined: Feb 2007
Posts: 1,161
Likes: 39
From: LOST WAGES
Turbo's work better with cams that have less overlap. I am running a turbo with 8 lbs of boost with my stock 4 cams. It runs strong, but when I hit 5k RPM's under full boost it stampedes and burns the tire. I am going to change my cams to run 4 intake cams. It will get rid of the stampeding and more low end power and it will lower my EGT.