hi guys and girls. I saw a cool chevy engine that runs in the correct rotation but the intake is the exhaust and exhaust is the intake..... it was on the HAMB a long time ago but i can't find it anymore. Can anyone help me with this. i have a spare stock 350 and thought... why not have some fun. the issues i see is spinning the cam and dizzy backwards they will want to walk out of the block, also the oil pump..... can they run backwards. I have a esky cams crank to cam gear drive so i can spin the cam backwards... ANY help would be awesome. Cheers Bruce TheMoonman Swallow NEW ZEALAND
I had an L-88 in a 67 chevelle in 1970 with a reverse rotation phase III L-88 cam and from what I remember the cam was ground funny? I believe it was a marine grind? I could be totally off base with my info as it was 40 yrs ago, I was a learning kid, and its now a fond memory. I wish I had the L-88 back as I know where the 69 vette is sitting that it came out of. the owner took a job as a traveling salesman and had a friend put a 307-2barrel motor in it for mileage and he got the motor for doing it. I paid 175.00 for it and WOW. the vette is still owned by the same guy, same house and still has a small block in it .I presume the 307.anyway my understanding was reverse rotation cams were for marine and off road use?
Wouldn't you just cut a custom cam that has the lobes reversed to make that work? In other words, set up to open the small valve as exhaust and the large as the intake? Reverse rotation would just turn the whole engine backwards.
Some guys experimented with the reverse rotation engines in circle track racing back in the day. Don't remember it lasting too long, or maybe it was banned.
Was used on some forced induction engines. Without a blower or turbo the small intake valves(exaust valves) will not help performance may look cool but not worth the effort.
Why would you except for looks? Heads are flow tested in one direction and I'ld suspect you would have a noticable loss in power. Are older heads more forgiving?
Bruce Crower played with a reverse induction SBC for Indy racing years back . I don't recall what heads he used or the outcome as far as being in competition but it looked impressive . Crower has always been an "out of the Box " tinkerer ,inventive ,wizard. I believe the style of rear motored cars of that era shaped the engine package. I know the Gurney/Westlake Fords had a similar set up with a set of 180 deg. headers snaking out the top where the intake would normally be.
If you take a reverse rotation cam and install it in a normal rotation engine, wouldn't that reverse the induction? If the cam lobes were symmetrical (I know some are not) the cam wouldn't care which way it turned.
Most lobes are not symmetrical, as far as the opening and closing side of the lobe are concerned. In your scenario with a reverse grind cam and a normal rotation engine the valve opening sequence would be correct, but the optimal valve timing would be all jacked up. BTDC would become ATDC, scavenging would suck (blow?) etc. It would probably run, but I wouldn't count on it running very well. I suppose it could be something to try on a Saturday when you have too much time and beer available.........
thanks for all the feedback guys, yes reverse induction is what im after...... i have a spare engine so just going to muck around with some mates and some beers. some one said today that maybe setting the came 180 out might work...... can only but try. thanks again for the wisdom.
cheers, yer not really after performance, got a couple of supercharge engines for that, just want to have some fun and make something different. going to turn my cam around 180 and wind the motor over and see what opens when.....
How will you get the starter motor to turn backwards, and consider the direction the bendix throws when cranked?
You guys are giving me a headache. The engine runs normal rotation. The CAM turns normal rotation, it just opens the exhaust when the intake normally opes and exhaust when the intake nomally opens. 180 out will do nothing. You need a came designed for reverse induction!!
Reverse induction is what he wants to do, not reverse rotation. However,on a reverse rotation engine such as a marine application,there are reverse rotation starters to spin the engine backwards. My friend just found that out when installing twin engines in his boat and West marine sold him two normal starters......he couldn't figure out why it was spitting gas out of the carb and not starting!!
what do you plan to do for exhaust? unless you run a full exhaust out the back, you will be asphyxiating yourself if you try to drive it. It really isn't a good plan on any level....
Iskys Norton Grinders are just dumb old machines. Once you figure out the timing sequince and the lobe orintation numbers, its just the matter of flipping trace standard around. Just dont expect them to do it for you for the same price as a normal cam grind , and it will have to be off a billet core.
Buick Nail Head had a benefit by doing this. But not Chevy for sure because of the valve and runner size as you stated.
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