pmansson
Well-Known Member
What´s the best choice here, when building a 3,5L fuel-injected engine ??
Pistons being equal to compression ratio.
Pistons being equal to compression ratio.
Camshaft and pistons for a 3,5
- Thread starter pmansson
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pmansson
Well-Known Member
Depends on what you want...Sure, so let´s narrow it down to a comfortable and sporty, allround car, rather than a flat out racer. Fuel economy is less important.
jranmann
Banned
Would that be compatible with the soldered chip version Motronic (first generation, as is my unit 11/82) or is that not the case?... I would appreciate your opinion of that particular cam's suitability for the M30B32, given our apparent lack of flexiblity in that our chips which are for the most part permanently mounted to the board... see below:
Of note: on the 3.5 head and complete overhaul: What's the old saying? "...any gain has a cost somewhere? "
There are other ways to achieve the same result bhp wise... and perhaps more efficient methods at that. I've decided after much thinking that for my own needs (a reliable, civilized power plant) I am gonna stick with the 3.2 (Motronic) managed system in lieu of a CSi setup or a dual overhead cam engine....It will be a standard/fresh 3.2 liter engine...stock cylinder head and associated engine bay electronics...
If one has the time, as I am going to make time for, I am having the head carefully ported by an expert on a flow bench which IMO is the most logical approach if gobs of driveshaft breaking power is not your cuppa.. but useful usable power is...acheived in part by also by replacing the valve gear entirely when adding the new camshaft, perhaps similar to the one mentioned above seems prudent and conservative.....
The 3.2 head (which does have slightly smaller valves) after the rework should do quite nicely, breathing much better after the porting, yet still making good use of the healthier cam (lose my CAT system finally) and continue to efficiently use a more standard 2" exhaust system with the 3.2 intake manifold being a non-problematic addition as I am also dumping the large stock brake booster and fitting instead the next generation HYDRO boost unit off an e24 of similar mid-80's vintage a plus that comes with power steering as well!
Remember too that when you use the large valve 3.5 head (9 to 1) your intake and exhaust will need work just as efficiently to maximise (or essentially take any advantage of the increased flow) any improvement the turbulance and flow characteristics aside...it also is more than likely an enlarged exhaust system 2.5" to 3" and installing the proper intake manifold so that the larger valves actualy have something consistent to draw upon will likely also be necessary...you gain you lose you gain again!
Cheers!
Ran
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Sounds like you're talking about an L-Jet system if it came on the 3.2. I don't know whether this cam will work with that system based on personal experience. I do know that the L-Jet system has some limited adjustability through the AFM and included O2 feedback in later years. I bet it will work, but check with Korman. They'll be able to give you a definitive answer. I will add that the performance gain was definitely worth the investment and this cam improved driveability across the board. The idle is a little rougher than stock, but acceptable, and the torque curve is absolutely amazing. I would add this cam, a set of headers and free-flow exhaust and reconsider whether the port work is necessary.
BTW, I should also add that that biggest intake restriction in the L-Jet and Motronic systems is the AFM -- the "flapper box" which senses the air flow. That -- along with a desire to maintain a stock CSi appearance -- led me down the road to a custom injection system which doesn't use an AFM.
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