1UZ-FE exhaust cams and porting for power
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1UZ-FE exhaust cams and porting for power
I am reading a book called "21st Century Performance" by Julian Edgar at the moment.
You can buy it from the www.autospeed.com site in the shop.
Anyway there are two particular chapters with very interesting information on the 1UZ-FE V8.
The first chapter "Engine and Driveline" part "camshafts" has a whole section about the 1UZ-FE camshafts and how they compare to other high performance engines. Standard specs are listed and they model changes (using Dyno2000 software) to the cams and resulting horspower increases.
The most effective would seem to be changing the standard exhaust cam for an exhaust cam with revised opening of 55 degrees BBDC (Before Bottom Dead Centre) and closing of 18 ATDC (After Top Dead Centre) (standard exhaust is 46 BBDC and 3 ATDC). This changed exhaust cam with the standard intake increased the horsepower from 260 to 300 !! (modelled on Dyno2000).
Although changing the exhaust cam (getting it welded and reground?) doesn't sound like a simple job.
The second very interesting bit is head porting. A 1UZ-FE head is flowbenched before and afterward being ported. Increases in flow on the bench usually relate directly to horsepower increases. After porting the intake flow increased by 19 percent and the exhaust by 14 percent!!! These are actual flow bench figures. Not only that but there are 12 full colour photos of before and after closeups of all the critical parts to pay attention to when porting. An extimated 20 hours was spent porting both heads.
I haven't heard of anyone ever trying different cams (only a supercharged 1UZ-FE, Ivan Tighe did those) or porting the heads for a street car -
Anyone heard anything or given it a go?
You can buy it from the www.autospeed.com site in the shop.
Anyway there are two particular chapters with very interesting information on the 1UZ-FE V8.
The first chapter "Engine and Driveline" part "camshafts" has a whole section about the 1UZ-FE camshafts and how they compare to other high performance engines. Standard specs are listed and they model changes (using Dyno2000 software) to the cams and resulting horspower increases.
The most effective would seem to be changing the standard exhaust cam for an exhaust cam with revised opening of 55 degrees BBDC (Before Bottom Dead Centre) and closing of 18 ATDC (After Top Dead Centre) (standard exhaust is 46 BBDC and 3 ATDC). This changed exhaust cam with the standard intake increased the horsepower from 260 to 300 !! (modelled on Dyno2000).
Although changing the exhaust cam (getting it welded and reground?) doesn't sound like a simple job.
The second very interesting bit is head porting. A 1UZ-FE head is flowbenched before and afterward being ported. Increases in flow on the bench usually relate directly to horsepower increases. After porting the intake flow increased by 19 percent and the exhaust by 14 percent!!! These are actual flow bench figures. Not only that but there are 12 full colour photos of before and after closeups of all the critical parts to pay attention to when porting. An extimated 20 hours was spent porting both heads.
I haven't heard of anyone ever trying different cams (only a supercharged 1UZ-FE, Ivan Tighe did those) or porting the heads for a street car -
Anyone heard anything or given it a go?
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