STR139 Camshaft

[Carsreunited]

Hi,<br>
<br>
Can anyone tell me the difference between the 139 against the 91 apart from the obvious model number difference? Is one more suited to a certain type of use than the other. If so what? Does one give bigger power gains than the other at certain revs?<br>
<br>
Any advice appreciated.<br>
<br>
Scott<br>
<br>
<br>
1979 Dolomite Sprint<br>
1974 Daimler Double Six VDP<br>
2000 Aprilia RSV Mille<br>
2003 Mini Cooper

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[SMIFTER]

STR139 is probably the most powerful cam out there but its a full race spec cam with a peaky 3500 - 8000 rpm power band. It needs double valve springs and may need additional machining to the head and pistons for it to fit. These are suited to 48/50 carbs and would probably be a pain in the arse to drive sensibly. Can give over 200BHP.<br>
<br>
STR91 is more suited to fast road cars as it has a 2500-7000rpm power band and can be used with single springs and standard valves and pistons. Its suited to 45 carbs and will still be drivable at low rpm albiet rougher than a standard car. Can produce 170 to 180BHP.

<p><!--EZCODE LINK START--><a href="http://www.smifter1971.pwp.blueyonder.c ... >Smifter's Dolomite Sprint Website</a><!--EZCODE LINK END--></p><i></i>

[speedracer]

From information supplied to me by Ronald:<br>
<br>
STR 0091<br>
Timing: 40/73-68/32<br>
Valve lift: 0.383"<br>
Duration: 286 °<br>
Power Band: 3000-7000<br>
Power: 178<br>
Application: Fast Road/Rally Gr.2<br>
<br>
STR 0139<br>
Timing: 68/92-76/56<br>
Valve Lift: 0.435"<br>
Duration: 324 °<br>
Power Band: 3800-7500+<br>
Power: 220<br>
Application: Rally/Race Gr.1<br>
<br>
<br>
... like SMIFTER said <!--EZCODE EMOTICON START :D --><img src=http://www.ezboard.com/intl/aenglish/im ... /happy.gif ALT=":D"><!--EZCODE EMOTICON END--> <br>
<br>
speedracer

<p><!--EZCODE LINK START--><a href="http://www.triumphowners.com/2">1975 Dolly Sprint</a><!--EZCODE LINK END--></p><i></i>

[Carsreunited]

Thanks. That will explain why my engine only sems to get going at the top end.<!--EZCODE EMOTICON START :rolleyes --><img src=http://www.ezboard.com/intl/aenglish/im ... s/eyes.gif ALT=":rolleyes"><!--EZCODE EMOTICON END--> <br>
<br>
I'm just in the process of approaching Jigsaw Racing to sort out my car as I live about 5 miles from them. I've had COD685T for about 2 years now and she is in need of some welding. <br>
<br>
I hadn't really been through the receipts file. The guy who sold it to me told me that it had a fast road cam so I was looking for the receipt expecting STR91 on it. Anyway, the receipt was for an STR139. The only other mods seem to be Gas flowed head and lightened flywheel and it has twin 45 dcoe's. It still has the original canister oil filter fer chrissakes!! I'll probably be looking for them to do a rebuild on it and just wanted them to see what it has had done to it by the previous owner. Its an inca yellow sprint that was around the Putney area in the late 80's, early 90's if anyone recalls the owner David McCann? Owned it for about 7 years from what I can make out I think he had played with it for hill climbing????<br>
<br>
Thanks for the response<br>
<br>
Scott

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