32 Valve camshaft options
01-01-2019, 10:13 PM
#16
Three Wheelin'
I guess I should have stated that I already have a set of Simard gun drilled cams. Since he isn't making them any more I can add the specs to the list
Intake:
Lift .450 Duration 226 @ .50
Exhaust:
Lift .420 Duration 220 @ .50
The LCA (Not LSA) is 110
These were designed by Mike Simard in conjunction With Harvey Crane of Crane Cams before his passing. Mike has since dropped from the 928 scene and I know that he made at least 5 sets of blanks of the gun drilled billet cams, but I don't know how many sets actually found homes in 928 engines.
Intake:
Lift .450 Duration 226 @ .50
Exhaust:
Lift .420 Duration 220 @ .50
The LCA (Not LSA) is 110
These were designed by Mike Simard in conjunction With Harvey Crane of Crane Cams before his passing. Mike has since dropped from the 928 scene and I know that he made at least 5 sets of blanks of the gun drilled billet cams, but I don't know how many sets actually found homes in 928 engines.
I thought you had a set of Mike's cams.
Louie
01-02-2019, 11:20 PM
#17
Rennlist Member
I'd suggest one of Colin's offerings depending on the ultimate use you intend for the car. You'll have a bucket of low/midrange torque so work on enhancing to top end. Your ITBs will help take care of that. The Ford 4.6 DOHC valve springs will work fine. They are of the "beehive" design. Tuomo has a lot of data on those.
01-18-2019, 11:32 AM
#18
Rennlist Member
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The full race cams #136/206 are also made and are going into my 7L stroker engine project. It is motorcycle profiles used for drag racing back in the 70´s and 80´s. The long duration cams will certainly add much power in the upper range but the low up to the mid range torque will suffer. I expect the 40% cubic increase and the possibility to adjust the cam timing and overlap will make the engine driveable in traffic. This is an experiment, if it does not turn out good I will put in some cams having shorter duration. The cams will not work well unless ITBs and tuned headers are used. The heads will be fully ported having 42/36 mm valves
https://rennlist.com/forums/928-foru...ughout-15.html (start reading at post # 218). Shaftless 55mm ITBs made by ATPower in England will be used.
Åke
01-19-2019, 01:40 PM
#19
Drifting
Ake:
12-26-2019, 12:06 PM
#20
Rennlist Member
My understanding is we have technology to make changes to lift/duration on existing camshafts...I'm thinking of increasing the duration of my '86 cams to match the GT etc. Does anyone have experience using these services and could make recommendation / give me an idea of costs?
This is something that would be done while replacing cam chains/pads/lifters type of job....any input appreciated..thanks.
This is something that would be done while replacing cam chains/pads/lifters type of job....any input appreciated..thanks.
12-26-2019, 12:10 PM
#21
Drifting
The S3 and GT cams are essentially the same except for lobe separation, so no need for modifications.
12-27-2019, 12:47 AM
#22
...
Last edited by Bigfoot928; 05-23-2020 at 02:44 PM.
12-27-2019, 06:54 AM
#23
Nordschleife Master
Another reason may be that the lifters are different. There are at least two kinds lifters out there in factory original cars.
Later cars may have been run more often with unsuitable oil.
Small sample problem, how many GT cams have you seen?
The adverse selection effect might be driving the loose good GT cams out of the market?
Finally, the later (better) cars may simply have been run more miles on average.
Last edited by ptuomov; 12-27-2019 at 10:54 AM.
12-27-2019, 10:47 AM
#24
Drifting