This is my first post in the forum - but this place has already been a great source of information for me. But I couldn't find the answer to my particular question, here goes:
I'm in the middle of a complete rebuild of a 327Q, the engine is out of a 1964 Tollycraft ski-boat that I am restoring. The boat originally had a Ford Interceptor in it, but by the time I became the owner (last year) that engine was long gone. But the 327Q is close HP-wise, and I didn't feel like shopping for an old interceptor so I figured I would go-ahead with the rebuild.
So I took the engine apart last year and took the critical pieces to the machine shop. The cylinders were bored, I have a new set of pistons, the heads were re-worked and I have a new camshaft. When I took the engine in I didn't realize that these engines had special cam's - but evidently someone at the shop did and they said they would replace the existing camshaft with a "marine" camshaft. I have the new camshaft, and I'm ready to install it - but now that I've done a bit more reading I'm wondering what I really have. I didn't get any documentation with the camshaft, but there are a few markings on it: GM18, 0650, and the end is stamped 944. It cost me all of $65 which makes me happy, but seems a bit suspicious in light of the prices I have seen quoted here. Does this mean anything to any of you? I haven't been able to locate anything on the 'net. What measurements can I take to determine if this cam is going to work for me?
That's it for now, but I know you all like photos so here is how the engine looked last night:
I'm assuming the cam is installed now. Do you have the old one, and why was it discarded?
The reference to "marine cam" may mean your motor is an opposite rotation to automotive standard rotation, which takes a special cam, starter, main seal, specific directional water circulating pump, and special distributor gear. If you're rebuilding a Q motor, you'll have all the right ancillary equipment, but if you start treating it like a stock SBC then you WILL have problems. Having said that, I'm not all that familiar with the Q, but they have a unique cylinder identification from all other small block Chevy motors and the timiming is different too. I have never heard a logical explanation for why they did this, so I'm assuming there isn't one.
The Q motors are great running motors, however. My Dad, now in his 80s, is running a pair of 327Q motors and they've always sounded good and run very strong.
Mark Weller has been all through one of his Q motors, and is our resident expert regarding everything about the Q motors, as well as being able to offer some great tips about how to varnish in a tuxedo too !
Derek where to start based on the information you provided I cant really give you much except the price makes me suspicious. My 350 Q cam cost me around 150 with lifters and pushrods and trust me lifters and pushrods are not that expensive the Q motor is not as different as everyone thinks it is but its not normal either. To be honest I do not know if it takes a unique cam or not I just know I didnt take any chances and ordered one from Robert Henkel up in Michigan. He had what I thought was a reasonable price on it so I bought it. The least expensive cam I saw for marine use on summits site was a comp cam for an SBC at $119.00 and it is your basic cam. First you need to know your motor is it a Q or QL model or left or right hand rotation looking at the front of the motor where the flywheel goes facing the flywheel does it turn clockwise or counter clockwise? That determines the direction or if you have the original exhaust manifolds with the chris craft plates they will have the model on them. (Hoping no one ever switched them) oh wait does it have a timing chain or gears? I almost forgot one of the easy ways you have it apart chain is a Q gears is a QL. But I can give you this markweller at sbcglobal dot net hopefully you can figure that out. Or 440 887-7912 if am not home leave a msg I will get back to you. Also try to find your receipt from the engine guy who sold you the cam try to find a part number or if you have the box it came in look at that the number you gave didnt get me anything on google so let me know what you have if you can.
Thanks for the help guys, sorry the information provided was a little thin. I am sure that it is a regular Q and not a QL, it has the timing chain rather than gears and I do have the original ChrisCraft plates with model# etc.
Today I called the machinist who did the work and sold me the cam, he said that it was a generic cam that was ground by a local shop - Delta Camshaft. I called them and here is the information they were able to give:
Intake Duration @ .050": 202
Exhaust Duration @ .050": 213
Duration is 267 (I presume for both intake and exhaust)
Intake lift is .400"
Exhaust lift is .410"
I haven't taken a chance to compare that to what is available from summit, etc; but I will do so tonight.
Derek call that shop that ground the cam back and see if they can give you a firing order for the cam if so post it here and I can tell you if it is right or not.
Good idea. I called them again, they said they are only aware of 1 firing order - the standard SBC firing order. They said that the particular grind I have is their standard marine grind which has a bit more lift. Otherwise the camshaft is OEM.
I know I have seen reference to ChrisCraft's "non-standard" firing order on here before but I think it comes down to how you number the cylinders, not in any change in the sequence. ChrisCraft uses standard numbering methods but they turn the engine around. Last night I went through the exercise of translating flywheel forward numbering to automotive flywheel aft - and the sequence was identical. Is that correct?
yes that is correct it is just shifted a little but a circle is a circle as long as the order is the same it dont matter that cam should work fine the only difference may be lift and duration and I cant tell you that because I dont know the lift and duration of the cc cam. I wouldnt think the CC cam would be that much different if at all from what I know it seems they are pretty much stock marine cams and since you are a single engine I would just use the cam you got.
here is what confused me in the past, look at the diagrams showing the flywheel end of the motor and the firing order.
Something Mark said months ago just (finally) sunk in. I can be trained, but sometimes it takes a lot of work.....
"Paul the Q motor has the cylinders numbered the same way as every other 350 SBC 1 being on the left side to the front of the motor. What throws most people off is the fact that the flywheel is in the front of the motor not at the back, the motor was not reversed it is just a flywheel forward motor. Here are some pics from my manual what you need to remember is the shaft to the trans is coming out the opposite end from the flywheel."
It finally dawned on me that a flywheel can be put on the front or rear of the motor. I had fallen into the mindset that the flywheel end of a motor is a constant that won't change, which is incorrect.
Thanks Mark, for clearing up this issue. The photo above shows a 327Q with a flywheel forward, with the motor pointing forward, and with the distributor in the traditional forward "GM" position. Now it all makes sense to me, duh!
I have seen several posts about engine rotation because that is probably the single most confusing subject in all of boat repair running a close second behind is AC/DC wiring, is the black wire hot or is it a ground. Any of us who fool with boat engines either figures it out or gives up and gets drunk. It is a true brain twister no pun intended.
Try it simplify the mystery by ignoring the prop rotation or transmission rotation direction. Also forget how the engine is mounted in the boat.
Focus on just the engine itself. Post 1950 V8 marine engines are derived from the auto industry. Pretend you are sitting in a'66 chevelle looking out the windshield. The engine is obviously in front of you. The flywheel is at the back or rear of the engine and the harmonic balancer is at the front up by the radiator. When this engine is running it turns counter clockwise(CCW) looking at the flywheel from the drivers seat. Pretend there is a piece of glass in the firewall between you and the engine and you can sit there and watch the engine run. The flywheel will be turning CCW or to the left. TO THE LEFT. This is also called "standard" rotation. This is not reverse rotation!
As far as I know there has never been a clockwise (CW) rotating V8 in a car or truck. Please correct me if I am wrong!
Now get out of your Chevelle and walk to the front and raise the hood. Look at the harmonic balancer. Lo and behold it is turning to the right or CW. The flywheel, crankshaft and harmonic balancer are all turning in the SAME direction, but you are now viewing it from a different direction. The auto engineers referenced engine rotation as if they were sitting in the car looking at the back of the engine! Some folks get confused because when the are viewing a running engine from the front, such as when setting the timing with a light, they see that balancer turning right or CW they think the engine is a right rotation engine. It is not.
STANDARD ROTATION=COUNTERCLOCKWISE=CCW=LEFT HAND
Firing order 18436572
Now enter the boat builders. In an effort to make a prop spin clockwise they decided to design an engine that could turn clockwise or to the right. On a twin engine boat we all know 2 props spinning opposite will benefit performance. I don't know why they cared in a single engine application, but they have installed both left and right rotation engines in single engine applications. I think it had something to do with offseting the torque effects of a full throttle launch but I don't know. Anybody?
Everyone loves small block chevy (SBC). SBC's have been configured as 265, 283,302,305,307,327,350,and 400 cubic inch variations. And a popular custom variation, the 383.
Install a starter motor on it to make it turn clockwise, of course when viewing the flywheel, change the rear main oil seal because until somewhat recently they only were direction specific. Will it run? Not yet. So far the block, crankshaft, rods and pistons are unchanged. The heads and valvetrain are unchanged. The camshaft and firing order is what gets changed. The firing order simply gets reversed. 18436572 now has to be 12756348. It is the same crank but it now turns CW. The cylinders now fire in a reverse sequence. How do you change firing order? At the distributor by reversing the plug wires. Leave number 1 alone and change the others.
The camshaft is where it gets confusing, because a standard engine will use timing chain setup, i.e. small gear on the crank, a gear exactly twice as large on the cam and a chain connecting them. The cam turns half as fast as the crank in case you didn't know. The cam also turns the same direction as the crank in this scenario. That is a problem in a reverse rotation engine because they need to keep the cam turning CCW so it does not alter distributor and oil pump direction. They solved that problem by eliminating the chain and using 2 gears which mesh together. So now the crank can turn CW and the cam will turn CCW. The distributor and oil pump still turn in the same direction. What is different? The valve timing has to match the firing order therefore the cam lobes are ground to match the firing order. Valve lift, duration, and overlap are the same.
I am no expert on the Chris Craft Q series, but the company threw a huge curve at us with those puppies. We call em queer because they are. They basically attached the flywheel to the wrong end of the engine just to make people crazy. Find the original distributor mounting hole in the block. THAT is the rear of the engine. Not the end where the flywheel is. Careful because Ford engines have the distributor on the front of the block. All the Q series are Chevy's, I think. Remember also that Chevy did not change their engine, Chris Craft modified it to their liking.
Also some applications of SBC 350 reverse marine engines have the pistons mounted backwards on the rods with the notch facing the back of the block, because the wrist pins are offset. Same pistons, just installed backwards.
Be careful about trusting an auto engine machine shop with a reverse rotation assembly. A lot of them don't get it, been there done that lol.
Bottom line, locate the rear of the engine, bump the starter, view crankshaft rotation
CCW=left=standard
CW=right=reverse
Sorry for the long post, Hope this helps, experience says it won't
Thank you all for your help, this has been a very informative thread for me - thanks for taking the time. I'm very glad that I have a normal Q and not a QL because it's all I can do to keep the normal one straight (amazing what turning an engine around does - several times during the last day I have been convinced that I had installed the pistons backwards).
I'm going to proceed with the cam that I have, this is one more issue I can check off my list. I'll post some photos when I make some significant progress (looking forward to applying that first coat of Chris Craft blue).
Confusing allright (this post has been edited for accuracy)
April 3 2008, 7:01 AM
Most of the time you are instructed to look at the flywheel to determine which way the motor is functioning, this instruction then gets very confused with flywheel forward installations. Then you have the motors that are really turned around backwards, that adds to the confusion. I think the safest way to really tell (from a machine shop point of view) is to find the traditional front of the motor. Just dealing with the small block GM (because big blocks and Ford small and big motors differ) that would be the place where the traditional distributor is mounted, on the BACK of the motor as it sits in the traditional automotive configuration(yes some of the old SBC motors had the distributor on the rear transmission case, more confusion). If you find the front of the motor, regardless of where the flywheel is mounted, or whether the motor is installed backwards or frontwards, THEN you can tell which way the thing is running by looking at the direction of the belts and accy gear. That is proof positive, regardless if CC says it's a RH or LH installation.
Now......looking at the front of the engine spinning, go to the rear and look again. THAAAAT is the rotation we're looking for. If it is spinning CCW when viewed from the rear, it's STANDARD ROTATION as in all V8 automobiles I'm aware of. If it's spinning RH, then it's the OPPOSITE ROTATION, with special marine cam.
Your machine shop will need to know, because if they don't..............ohhhh brother.............are you in for some pain and suffering. They should be able to tell once they get in, but if you're paying the tuition, get out the $$$.
To add to the confusion...............almost ALL, perpahs ALL single engine runabouts of inboard configuration have a RH prop. Does this mean they have a RH (opposite rotation) motor in every case? "NO"...........because if that motor is turned around backwards with the tranny mounted on the front, you have a LH standard automotive rotation (with standard cam) driving your prop in RH config.
To me, being an engineer by trade, this is not unexpected. Engineers have often worked long and hard, overtime into the night, to make things more complicated than they need to be.
Tom
edit comment: an apparant error which looks like an oversight has been corrected in bold print, and this was necessary to avoid publishing incorrect info and creating confusion. If I have messed up this post, Tom, please advise and I'll make whatever correction is necessary. Thanks, Paul, forum moderator.
This message has been edited by FEfinaticP on Apr 3, 2008 4:03 PM
Hang on a second, this is confusing enough. Greg said that the distributor is in the back, Tom said it is in the front. Which is it? Based on the automotive books that are guiding me through the re-build it seems to me that the distributor is in the back of the engine, but those books (annoyingly) don't ever explicitly define the front and the back of the engine - it is just inferred.
Here is one (crude) diagram I found online:
The image seems to align with what I have assumed is the front of the engine.
Let's get more basic. Is the thrust bearing in the front or the back? On my engine the thrust bearing is on the same end as the distributor and the flywheel and opposite the balancer and cam cogs/chain.
I read through Tom's post and I think he has one word out of place, which appears to be in error and which appears to have tossed this discussion into a temporary tailspin. I'll read it again and make a correction if necessary. Tom, please chime in here too, I don't want to edit your post unless it's necessary.
The traditional distributor on a small block Chevy (and big block Chevy) is in the back of the motor, as shown here. They put it there to make it harder to get to, and to induce as much back pain as possible.
The traditional distributor on a small block FORD (and big block Ford) is in the FRONT (where it should be).
F = Ford, F = Front (as in BETTER IDEA).
I love a good Ford- Chevy fued, does Chrysler get to play?
April 3 2008, 6:02 PM
Yes the distributor, cylinders 7 and 8, oil pressure sender port, bell housing mounting surface, oil filter mounting boss, original starter mount, the large casting numbers with the clock mark, are all at the rear of the block on small and big block Chevy's.
Paul, you have fired the first volley! LOL
With all due respect to your grandfather who owned a
Ford dealership!
The distributor is driven by the cam, and the bottom of the distributor shaft drives the oil pump. Chevy put the oil pump and pickup at the rear of the oil pan. Which way does the oil move when you accelerate. To the rear, which is where the pump is, where it should be. I know you have seen those funky double sump Ford pans, or the sumps on the front of the pan. Chevy V8 oiling design is second to none. I give you that the distributor is harder to get to, but not on a boat.
Chrysler (of course) makes a fine motor, as did AMC for the Graymarine series, often mistaken for the Chevy 327.
I like to remind Chrysler fans that when Richard Petty defaultef to Ford for one season, he beat the best machinery Chrysler could put on the track. So much for the "unbeatable hemi", snicker. Not many MoPar motors in the Commanders, however.
I actually love the SBC motors. I have a BBC in a C60 farm truck, it's a 366 tall decker. I can tell you that blankety blank distributor is in the WRONG place. Standing on the bumper leaning over the motor trying to even SEE those contact points is just nuts. Ford did have a better idea, but you are right, in a boat it really makes no difference. I'll be running my SBC on Saturday, by the way, and I'll post photos. Stay tuned!
Sorry to let you down, guys. It was a dumb mistake I made, and I knew what I was thinking but my fingers would do what I wanted them to type. There is a long lag time between what I think and what I type. Thats my story and I'm sticking to it.
Good to see a correction is made before someone experiences any heartburn due to passing on bad info.
Ok one more time boys and girls the CC Q motor is not some extremely unique motor its a std small block chevy just turned around they didnt modify the crank or cam shaft they just picked it up and spun it 180 degrees and put some unique parts on it to make it work. Power is being taken from what you would normally consider to be the front of the motor they did this by using a different setup on the "rear" of the motor to hold a water pump etc look at this photo
That is the rear of the Q motor it is also the end from which the cam was inserted something unique to the q is there is a "cam" bolted to the end of the cam shaft to drive the fuel pump which goes on top of that housing. Ok now this photo
This is the front of a Q motor the flywheel is inside that housing which also holds the water pump etc you can see the pulleys bolted on to the "rear" end of the crankshaft and the distributor is now at the front of the motor. Some other unique things about the Q are the intake for water inlet to be in the "front" I am in firm belief that if you wanted to you could take any small block chevy and turn it into a Q with nothing more than the intake, the two housings at each end of the motor the few parts that go on the crankshaft and camshaft its mostly "cosmetic" stuff the block crank pistons etc are all stock items it is the exact same thing. Ok enough of this I need to get back to work.
You brought up another topic that I could use some advice on if you have any ideas: My fuel pump cam has a groove worn in it from the fuel pump lifter, so I'd like to find a replacement if they exist. The shop that re-worked the engine didn't recognize it as a standard automotive part, and the closest thing that Summit has is eccentrics for Ford motors.
Does anyone know of a source for these? I'm perfectly willing to go to a marine source (I'll be calling around this afternoon), but if there is an automotive source it would be preferred since the moment you call something "marine" the price seems to go up.
You are going to have to go marine and most times yes the price goes up but there are reasons for that for one you need to use marine carbs alternators starters etc for safety reasons for one they are designed for a closed environment and the posssibility of fumes etc they are made explosion proof for the starter and alternator so there are no sparks. Dont skimp and use auto parts except for things like gaskets and standard parts. Now as far as where you can get a new cam for the end of the cam I would try Robert Henkel at http://www.chris-craft-parts.com phone is 810-748-3600 or you can try Earl in Harrisson Twp Michigan at http://www.marine-sales.com/ phone is 586-468-0937
and there is Danny Cook down in southern Ohio but I don't have his number someone else here on the forum will though.
Being the proud owner of a pair of Qs, a lefty and a righty, I have been following along with some interest. This post has caught my eye, and now I'll pitch my 2 cents in.
Derek, you must never use car parts on a boat engine. Yes, marine parts are more expensive, and along with gaskets and such you can also use automotive sparkplugs and ignition points/condensers. The automotive versions will rust faster, but the engine will not know, or care, and they are the kind of things you replace every year anyway.
The automotive parts you can't use are;
Fuel pumps, car fuel pumps have a weep hole in the bottom of them. If the diaphram busts gas leaks onto the ground under the car. Marine fuel pumps do not have this hole, when they bust a diaphram the gas leaks back into the crankcase. This is why you check the oil before you go out and after you get where you are going.
Carburators, same deal, automotive versions have vents in the top of the float bowels to let excess gas out of the top if the float needle sticks, marine carbs are vented into the thorttle bores, for the same reason that marine fuel pumps have the internal drain. The idea is to keep raw gas in the engine, and out of the bilge. It is a lot harder to blow the boat up if there is not gas in the bilge.
Starters and alternators for marine service are spark protected. Car parts are not. The marine versions have spark arresting screens, different brush material, and some makes of alternators have gasketing between the case parts and bolt on regulators that the car parts don't have. Don't let anyone tell you that a starter is a starter, and an alternator is an alternator it aint so.
All distributer caps are vented, if you look a new one for you car you will find a small hole near the base of the cap, that is the vent. What you won't find on the car version is the small spark arrestor behind the hole. By the way, Not all marine caps have a spark arrestor, on the ones that don't (like a Mallory flat cap) the way the distributer housing is constructed when the cap is on, the ridge in the housing serves as the spark arrestor.
The idea is to contain stray sparks that could happen. Stray spark+hot engine+slight fuel vapor from hot engine=BOOM.
Yeah sure, I know we all run the blowers for 5 minutes after refueling, especially when there are 10 boats waiting for your spot at the fuel dock, and the dock guy is telling you to get going, but better safe than boom.
Ok, I was aware that there were differences between the marine and automotive carbs and fuel pumps, but not the starters, etc. And the flame arrestors, those are used all over the place on aerospace components to make them explosion proof - didn't know they were on distributor caps though - thanks for the tip! I'll make sure that the parts which need to be marine will be. I guess my point was that a cam is a cam (so long as the material and dimensions are good). So if they were used in an automotive application that would be my first choice. But it doesn't sound like they are so I'll give the vendors that Mark listed a call.
You are absolutely right in that any SBC (283, 305, 307, 327, 350 even 400 - though I wouldn't recommend that one as the unique harmonic balancer, necessary for proper balancing, goes bye-bye), can be turned into a "Q" as long as the "Q" components are handy. Been there, done that. Other than the "Q" specific parts, the issues are really only, as we all know, the cam and the heads (nothing too hi-perf).
The real bear is getting the flange off the "front" of the crankshaft. You have to be very motivated!
Mark, I am really sorry to beat this horse but since you are the resident expert on the Q design, do you know what the reason for the initial design? It seems as if they were trying to develop an engine capable of turning a right hand prop, so instead of designing a reverse rotation small block, they turned a standard engine around, developed the front and rear castings, etc and voila, now you can turn the prop to the right. But why the need to turn the prop right CW in a single engine boat? I think question has been asked a couple of times. But then the question is in a twin engine boat, to achieve a left and right hand rotation prop setup, they still were faced with designing a reverse rotation engine for the other side, so now it seems they doubled the engineering effort, and EXPENSE. What am I missing? Those extra castings and parts cost a bunch of money for a relatively low production marine engine.
My understanding for the Q design is that Chris Craft was looking for a way to lower overhead clearance or fit a std motor in a smaller space vertically. By swapping the motor around you can mount it on a down angle put a shim or custom maniflod on the carb and get a lower profile for mounting it. Now where did I leave that Chris Flyer for the Q motor oh here it is. The Q motor in the 350 version was a mere 18 and 5/8 inches form the center of the crank to the top of the flame arrestor with an additional 8 3/4 inches to the bottom of the oil pan you are only talking a motor 27 and 3/8 inches tall overall and that is with an oil pan that holds 6.5 to 7 qts of oil. Now the 350 G inboard motor which I dont have a lot of specs on has an above center line height of 20 inches so it was a bit taller. Chris Craft called the Q "A good commercial fishing boat engine." I guess because of its lower profile and flat torque spec from about 2900 rpm to 3300 rpm. The amazing thing about the Q is that it cost more than the base 350 which put out more horsepower at 260 as compared to the Q's 235. I have a Chris Craft marine engine price list from 1973 which states the 350 G with a 2.5 to 1 trans was $2695 but a 350 Q with a 2.5 to 1 trans was $2830. I also have a 1972 price list and the 427 with 2.5 to 1 is listed at $3320 the Q in 1972 was $2750 it appears that 1972 was tha last year for the 427 as it is not listed on my 73 list from Sept of that year my 72 list is from Feb.
Thanks for the info on the dimentions of the motor Mark. I have my own theory and share my 2 cents. When the flywheel is in front of the motor, it sits much higher out of the bilge and less likely to scoop up bilge water.
I had a 24 Penn Yan tunnel drive which was a conventional inboard and sat very low. Any rain water or wash down would cause any water to run to the stern when planing off and the flywheel would act like a water wheel therefore causing my starter to have a life of about 2 months. I know that a plastic shield (shroud) was installed in that model to minimize the waterwheel effect, but that did not solve the problem. Paul, I belive that you stated that you experienced the same effect w/ your 20ft inboard.
Flywheel forward, Higher out of the bilge. Certainly can make a differance for smaller boats. I have not heard of this from anyone, Just my opinion.
You got it Bill, on my two runs last year in the Skiff, both being basic shakedown cruises, I encountered bilge water. The rudder log was fine but there was a seepage I was unaware of around the actual rudder block, etc. Water in the bilge was sprayed all over the place. Realizing this I put it up on a plow and used the aft bilge pump to get rid of the water, but when I got back to the docks and slowed down, more spray. Aft flywheels are NOT a good idea in smaller boats. In my 35' Sea Skiff, that boat never really had a lot of water sloshing around, it had a bigger hull to accept water if it had a leak, and the motors (327F, flywheel aft) were mounted so high it made no difference. In smaller boats it really makes a difference. You get a product in the hands of the general public spraying water around the engine compartment, you have a big problem with call-backs, dissatisfied customers and a tarnished reputation. I'm sure this entered into CC thinking, and it may well have been "the" prime reason because flywheel forward makes all the sense in the world on small boats.
Now that is a good explanation. The things we learn on this forum. Keeps the starter up high also. That is probably why Mercruiser sealed the bellhousing on their engines, but that did not keep the starter out of a high water dunking, which would generally ruin it especially in salt. Thanks for the replies!
