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I looked both here and on the Yahoo group site for a post that had stock cam specs for 1.9 engines 1970-1975. It seemed like Otto had posted it but I could not find this. Anyone know where it is hiding??
 

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.390" intake/.400" exhaust, 198 degree duration @ .050 peak power at 5200 rpms
 

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Discussion Starter · #3 ·
Did the FI Opels of 1975 share the same spec?
 

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Discussion Starter · #4 ·
Also on a stock cam. what would be the intake centerline?
 

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The peak power of a stock cam is 5200 rpm???? that doesn't seem right, the additional duration of 300º cam would probably peak at over 8k and it seems difficult enough to get a safe redline of 8k let alone the maximium power at that point.
 

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jordan said:
The peak power of a stock cam is 5200 rpm???? that doesn't seem right, the additional duration of 300º cam would probably peak at over 8k and it seems difficult enough to get a safe redline of 8k let alone the maximium power at that point.
Note that what was quoted was the duration @ .050" tappet rise. A racing 300 degree cam would usually have somewhere in the 255-270 degree @ .050" range (depends on the cam manufacturer's design, and whether it's a hydraulic, solid, or roller cam). Peak power in a Opel 1.9 with a cam like that would usually be 7400-7800 rpms, depending on the header size and length, intake runner size and length, carburetors used, lobe separation angle, and intake centerline (advanced or retarded cam).
 

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azopelnut said:
Also on a stock cam. what would be the intake centerline?
Lobe separation angle would be 110.5, intake centerline 111.5. So it is factory ground 1 degree retarded. Part of the reason for an Opel's lack of torque, in conjunction with the low compression and short stroke.
 

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azopelnut said:
Did the FI Opels of 1975 share the same spec?
Bob? I assume the specs given are for the hydraulic grind cam. Paul's question also interests me. Is the '75 cam the same?
For that matter, are there other differences between the years?
Anyone have the specs on the early solid grind cam?

This is all of special interest to me, as I have a NOS OEM 3-bearing solid lifter cam (in original GM packaging!) and a '75 SportWagon with factory EFI that I have built a 3 cam bearing head for. So I am planning on getting the said cam re-ground to a hydraulic profile, but I was thinking I might also get it ground a bit different to take advantage of the high compression pistons and such. It would seem I should also get it "advanced" a bit, to compensate for the head and block re-surfacing.

Any suggestions as to what other cam specs I should ask for in this engine? I would prefer torque to high rpm HP. Thanks!
 

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kwilford said:
Bob? I assume the specs given are for the hydraulic grind cam. Paul's question also interests me. Is the '75 cam the same?
For that matter, are there other differences between the years?
Anyone have the specs on the early solid grind cam?
I've never had a '75 cam measured, but my Opel microfische says it's the same part as '71-'74. European-spec GT/E cams were supposedly different, and superior to the US FI cams (the GT/E 1.9 engine had flat-top pistons and was rated at 105 ps/103 hp vs. the US-spec 80 hp).

The solid lifter cams had less valve lift than the hydraulics, but more duration (+4 intake, +9 exhaust).

Bob
 

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kwilford said:
Bob?
This is all of special interest to me, as I have a NOS OEM 3-bearing solid lifter cam (in original GM packaging!) and a '75 SportWagon with factory EFI that I have built a 3 cam bearing head for. So I am planning on getting the said cam re-ground to a hydraulic profile,
It does seem to be a pity to hack into a perfectly good (new!) solid lifter cam as someone out there must be looking for one. Have you looked at eBay.UK for replacement Manta cam kits? They generally go for around GBP30 for cam and lifters - new! The 2.0L Manta cams are hydraulic - except for the GT/E one which is, from memory, a solid lifter grind that is slightly "hotter" than the early solid lifter grind.
There seems to have been only a 3-bearing solid and four bearing hydraulic cam used for many years in the 1.9L motor as there is just two part numbers in the Parts Book.

The publishing of too many cam specs could become detrimental to "stock" racing classes - hence the reluctance for people to print them ....... ;)
 

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Cam specs

azopelnut said:
I looked both here and on the Yahoo group site for a post that had stock cam specs for 1.9 engines 1970-1975. It seemed like Otto had posted it but I could not find this. Anyone know where it is hiding??
Hiding here: Opel cam specs
 
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