Ok guys I have installed a few cams in my day but I think I may have messed this one up somehow. After the Vette build I had the factory LT4 cam lying in the top of my garage collecting dust. So I decided to put it in my boat. I put the cam in the boat a few months ago and just got it running yesterday, so from what I can remember I put the cam in correctly. I used a cloyes double roller chain with the 3 key ways.

When I put the distributer in I brought #1 to what I thought was TDC with the mark on the balancer at 0 on the pointer. I Installed the distributor with the rotor under the #1 plug wire. When I hit the key it popped threw the throttle body. I figured it was 180 out so I brought #1 back up and pulled the dis. and spun it 180. The boat started but runs like crap. So, I tried to adjust the timing, with my timing light, and the mark on the balancer was not showing up no matter where I moved the distributor. So, I shut it off and smeared some orange paint on the balancer exactly 180 degrees around from the factory timing mark and that mark shows up with the timing light!! Is it possible that I have the cam 180 out and the motor still run? I am really confused.

I also installed fuel injection on the boat. I pieced it all together with stuff I had lying around and some junkyard parts. Maybe the computer is causing this? Oh, and all my timing was done with the brown wire to the dis. disconnected. Any ideas?

http://s105.photobucket.com/albums/m...t=CIMG1444.jpg

 

Need some clarity. If the cam came out of a LT4 which I assume used a opti. Sounds like you installed it in a engine that does not use an opti. Is this true, I was not aware that could be done. As we all know there is no timing when installing a opti correctly and lining up the shaft.

Just trying to visualize what you got there so all answers are correctly targeted.

 

I don't think you can have the camshaft 180 out. The crank rotates 360 for every 180 of the cam, so the cam dictates whether the piston is under compression or exhaust, power or intake stroke. #1 at TDC is still at TDC whether it is in power stroke or exh.

Did you degree the cam? I'd start over with a degree wheel.

I have no idea how you got it to run...GOOD JOB!

 

Yeah I know, that is what is killing me I dint even know how the stupid thing is even running. I am beginning to think that I might have some wiring problems between the ECM and the distributor. I made my own wiring harness.

No I didn't degree it in, I figure its a factory cam and all other parts are factory.

 

Yes you can run the LT1/4 cam in any 1st gen small block. My boat motor is a 305 factory roller block, so I got all the roller hardware to run a roller cam. The only problem is that there is no fuel pump lobe, but I went fuel injected so I am using an electric pump. The dowel pin is also a little long so I ground it down to keep it from hitting the timing cover.

 

You can have the distributer in 180 out.(but they usually don't run) but its worth it to: Pull the #1 plug turn the engine over until you have compression and stab the distributer in with the rotor pointing toward number 1 Wire. You should be in the ball park or roll the engine one revolution and install the distributer using the damper mark.

 

I have done this.....3 or 4 times...I am mainly concerned about why the mark on the balancer is not showing up with the timing light and the one that I put on the balancer 180 degrees around the oppisite side of the balancer is. I am pretty sure the dis. is not 180 out because I had it that way once before and it was popping threw the TB and its not doing that now.


I know my timing light is good because I checked it on my truck and is dead on.

 

you can't have the cam 180 out.. its just that the distributer will have to be 180 out from the reference point which you think is tdc which it is just on the wrong stroke.. i did that once with my camaro and i just had to adjust the distributer.. i was freaking out cause it wouldn't start with a few thousand just sunk into it. and if its still running like crap you may not have the firing order right.

 

I don't want to sound like a complete idiot here, but I seem to recall having read somewhere that some marine engines turned opposit from automitive engines. Not sure if this would cause problem or not, just an idea, maybe someone knows for sure,

 

No they dont spin backwards. I have already been down that road. Even if this particular engine did spin backwards I have changed out everything that would make it do so.

 

Did you use the boat balancer with it's timing marks or a different balancer? It almost sounds like something isn't right with the timing marks or the pointer location or something of that nature. If you re-checked your work as much as you said you did then I'm sure you aren't 180 out. I honestly don't think it would run at all if it were 180 out. You used a factory roller block 305 and an LT4 cam, which is a factory roller, so there should be no problem there. I can't see the cam being out 4* making that much of a difference, and I don't think it can be out more than 4* either way because that is all the adjustment they give you in the chain set. ( I could be wrong there, every time I installed a cam I installed it at 0, every time I degreed it I ended up at 0 anyway) Also verify that the boat engine used the same firing order as the LT4. Be sure you are hooking the timing light up to the #1 cylinder wire as I have seen that mistake made before. Let us know what it was once you do get it figured out.

 

What dan0617 said. I had a damper crack,got a new one put it in, car ran like crap. Timing was way off,retarded. Seems thereis more than one SBC damper,400 dampers excluded. I would pull the left valve cover feel valves and pistons until I was absolutely sure #1 was actually at TDC and go from there.

 

Ditto what Muffin posted. I always found that rotating the engine to TDC on the compression stroke saved a lot of grief when installing the distributor. One tooth off will put the timing mark out of sight of the light. Later! Frank

 

You need to be real careful running a car cam in a marine motor. Boat motors tend to have less duration to avoid water that is used to cool the exhaust from being sucked into the motor. Did you do anything with your rockers since I believe the stock merc rocker are non adjustable.

 

Remember when you set the distributor to TDC cyl 1, the timing marks on the gear are at 12:00. Both of them. When the marks are at 12:00 AND 6:00, you're at TDC cyl 6, not cyl 1.

 

I am running the stock LT4 cam which has low duration, should be no problem.

I had the heads prepped for screw in ARP studs and installed 1.6 roller rockers. Fully adjustable.

 

Well it looks like I had 2 things going on here. For one the distributor was bad and I had it in 180 out. After stabbing in a new dis. and making sure I was on the #1 comp. stroke she fired right up and ran smooth. Now I have a fuel injected LT4 cammed 305 in my boat.. Cant wait to get it on the water this spring.

 

n/m see you got it fixed..

 

Great to see you got it fixed. Thanks for the update!

 

Glad to hear you got it running.