I need advise on proper timing set up for IH345 with split duration cam & Pertronix

[Rentalman]

Hi all. I hope you all had a great Thanksgiving. I started my 74 Scout II project almost 3 years ago. I'm finally at the point where I got the engine started today. I bought this 74 Scout II non running. I have no idea what this 345 should sound like or respond like. Definitely different sounding than my 800B with a stock rebuild on the 304. I have my build progress in the forums under readers ride, 74 Scout II Rebuild/Restore and Instagram 74_scout_ii_reviver. This engine originally had a 4-barrell Thermoquad (the one with the plastic base). Anyway I've changed it up. The engine has been balanced and blue printed, polished and ported heads, removed the injection tube humps and got rid of all the emission stuff, Isky split durration cam, Pertronix Igniter III and Flame Thrower III coil, 2-barrel manifold with Holley 2300 0-7448 2-barrel carb and Stans Ceramic Coated Try-Y Headers. I removed the distributor from the engine to use the oil pump drive tool I purchased from IHPA to prime the engine with the 6-quarts of Driven Engine Break-In Oil. I re-installed the distributor lining up with all my marks made prior to pulling. First off I was not getting fuel to the carb. I was in touch with the mechanic that helped me with a lot of this build. I had to pressurize the fuel tank with my compressor nozzle. Ok now I have fuel in the carb bowl. I got it running for a short time yesterday then could not get it to restart. It would crank over fast as I have the mini hi torque starter. Sometimes it would just stop turning. Sometimes when it would do that I would loose complete electrical power. I re-wired the Scout with a 14 circuit Quick Wire Kit also purchased from IHPA. I was very methodical when rewiring studying the install book and the scout wiring schematic. My mechanic friend said the distributor may be to advanced and I may have also flooded the carb. Once again I got the no. 8 cylinder on TDC, checked the location of the rotor to be lined up with the no. 8 spark plug wire on the distributor cap and checked the location of the distributor round star looking thing in relation to the Pertronix pick up. Today I pulled the distributor and moved it over one or two teeth clockwise so I could gain more retard. Now I have the ability to retard the distributor more. Now when trying to start the Scout you can tell it almost wants to start. The more I retarded the distributor the closer it got to firing. And again while trying to start again I lost all power. I'm not sure if this is the Pertonix causing this or not. I've checked all fuses and their good. Its almost like something is cooling off then its ready to go again after a few minutes. Finally got the Scout started and ran it for a minute and a half. I could not apply the manual choke I installed as it would want to die. I kept my foot on the pedal to keep it running. I did not have the time tonight to let it warm up enough to let it idle on its own. I know I need to get it running some what smooth so I can break the cam in at 2200 - 2400 rpms for thirty minutes. While running to me it feels like its running a little rough. It did not backfire at all and was not blowing any black smoke as to running to rich. I'm going to try and upload the video on Instagram as to offer what it sounds like running. Here are the pictures from TDC. Thank you for any and all advise.

 

[Zaedster]

You shouldn't have to mess with anything other than idle for the 7448 Holley. Either your firing order is off, or your timing is too retarded. If the timing is too advanced, it will act like it's struggling to start with the starter. Have it at zero for the first start, then walk over and advance it until it runs smooth. The rotor relation doesn't really matter, as long as the rotor is in-line with the no. 8 on the cap. I typically line up the rotor on #8 TDC pointing straight at the top water pump bolt.

I doubt the Pertronix is going out, you can bypass all your wiring by simply adding a wire to the positive side of the coil to the battery if you are suspicious of a fault.

 

[Rentalman]

Zaedster thank you for replying. I did get the engine on TDC from cylinder no. 8, rotor lined up with plug no 8 on cap. In that position the engine would not start. I had to retard, turn the distributor counter clock wise a few steps at a time until it finally started. The 2nd picture above from the left with the black marks on the distributor reference rotor at plug wire no. 8 at TDC. I had to retard the distributor counter clockwise until the rotor at no. 8 is now positioned a little past the water pump bolt you referenced to get the engine to start. Would you think I need to pull the starter up to advance another tooth or two? Also when it was running yesterday I realized I forgot to plug the vacuum port. I removed the vacuum line to the distributor as I had the timing light ready. So it was running with a vacuum leak. Is the split duration cam a mild cam? I can not tell if that is the cam that is causing the lobie sound or its running out of time. When running it does not backfire, the exhaust does not blow black smoke and it doesn't diesel when it dies. If you get a chance can you go to my Instagram account 74_scout_ii_reviver. I have a video of it running so you can hear what it sounds like. I'm at a loss. Thank you for your help.

 

[int77345]

wonder if you found top dead center on the exhaust stroke and not the compression stork ? is that possible ?

 

[Zaedster]

Zaedster thank you for replying. I did get the engine on TDC from cylinder no. 8, rotor lined up with plug no 8 on cap. In that position the engine would not start. I had to retard, turn the distributor counter clock wise a few steps at a time until it finally started. The 2nd picture above from the left with the black marks on the distributor reference rotor at plug wire no. 8 at TDC. I had to retard the distributor counter clockwise until the rotor at no. 8 is now positioned a little past the water pump bolt you referenced to get the engine to start. Would you think I need to pull the starter up to advance another tooth or two? Also when it was running yesterday I realized I forgot to plug the vacuum port. I removed the vacuum line to the distributor as I had the timing light ready. So it was running with a vacuum leak. Is the split duration cam a mild cam? I can not tell if that is the cam that is causing the lobie sound or its running out of time. When running it does not backfire, the exhaust does not blow black smoke and it doesn't diesel when it dies. If you get a chance can you go to my Instagram account 74_scout_ii_reviver. I have a video of it running so you can hear what it sounds like. I'm at a loss. Thank you for your help.

I watched your video. It is hard to tell from it, however it doesn't sound right as you say. The exhaust notes should be smoother. It also should idle. This all comes back to timing.

The split-duration cam is considered to be a "mild-cam."

Post some detailed pictures of your engine i/e routing of hoses...etc.

 

[ihpartsjeff]

Also put a vacuum gauge on it when tuning. You should see around 15" of vacuum at around 750-800RPM. If you are not seeing that, then yes something is wrong either tune wise or installation wise.

 

[Rentalman]

I watched your video. It is hard to tell from it, however it doesn't sound right as you say. The exhaust notes should be smoother. It also should idle. This all comes back to timing.

The split-duration cam is considered to be a "mild-cam."

Post some detailed pictures of your engine i/e routing of hoses...etc.

Zaedster, here are the pics of the hoses I believe you would like to see. Timed Spark Port to Dist Vacuum Advance, PCV Vacuum port to PCV to valley pan, spark arrester to air cleaner. The only other hoses on this are upper & lower radiator hoses and the heater hoses. In that video I did have the hose off of the disributor and I forgot to plug it. So the engine was running with a vacuum leak from the carb timed spark port. Thanks again for your time and help.

 

[Zaedster]

Looks correct.

I can tell your distributor is in a funny spot. You want the vacuum advance clocked more in the center of the water pump housing and cylinder head. This leads me to believe you still have a timing issue of some sort.

Watch this video:

Remove all your wires and redo it after watching the video.

This was years ago, this is what the cam should sound like:

 

[Rentalman]

Zaedster, thank you for all the advise and especially uploading the video of your truck so I could listen to it. I did watch the video prior and will watch again. I've checked all my spark plug wires and they are all fully seated in the correct firing order clockwise on the cap with 8 infront of water pump bolt. Obviously I have something off as this task seems really easy. Get engine on TDC. Make sure rotor is position on # 8 plug wire contact of cap. I fully understand the process but I guess being off 1 or 2 teeth make all the difference.

 

[Hondo]

int77345's comment above is critical, hope you verified it.

 

[Rentalman]

Zaedster, I watched the video again today. My plug wires are all in the correct firing order and seated correctly/snug in cap and on spark plug. I will have to confirm tomorrow night if I am on TDC when I have my wife available to plug no 8 spark plug hole. Tonight I cranked the engine over myself watching where the rotor ended up when I felt the compression and looked at the marks on the harmonic balancer when they were lined up on TDC. The rotor was not lined up with the water pump bolt as it was more between water pump and valve cover. I initially moved it this direction to gain more retard as I could not get it to fire when I had it lined up with water pump bolt originally. I've attached new distributor location and spark plug pics. Some of the spark plugs are pretty soaked oil/gas? The plug condition is after a total of three minutes of run time. Should I go out and buy a new set of plugs.

 

[Winchested]

Just hit the plugs with brake clean. Did they get the initial cam timing correct when rebuilding the engine?

I had issues like that first time I put mine back together. Had the firing order going counter clockwise rather than clockwise.

 

[Rentalman]

I hope the engine builder got it right? It is a reputable builder here in SoCal. They rebuild my IH 304 that runs great.

 

[Zaedster]

Give me a call, 530-274-1795 or email me; zaed@ihpartsamerica.com.

I hope the engine builder got it right? It is a reputable builder here in SoCal. They rebuild my IH 304 that runs great.

 

[Rentalman]

Hi Zaedster,

I'll send you a email.

 

[Rentalman]

I finally got the Scout running with advise from Zaed, Darren and a retired co-worker mechanic friend of mine Lee. I had to pull the distributor out and move it clock wise a tooth or two. It landed back where Lee my friend had originally set it. I believe most of my problem was me flooding the engine on the first time I tried to get it running. After that is when I made changes. Anyway distributor is back where it needs to be. I did get it running last weekend for 25 minutes long enough to break the cam in. While it was running it did have a exhaust leak. After running it I removed and replaced the break-in oil and filter with the same.

Earlier this week I found the leak, it was a threaded bolt hole on the no. 7 exhaust port that would be to bolt down a heat shield for the exhaust manifold. Yesterday I went to start it, it would run for few seconds, backfire then die. I did not change the timing from the last time it ran. Today I called my friend Lee, he told me to advance the distributor. I did and it fired right over. To keep it running I lightly had my foot on the gas pedal to let it warm up some what so I could apply the manual choke. Eventually I got the choke on and I could remove my foot from the gas pedal. I checked the timing with my timing light and the timing is around 8 deg. During the 20 minutes of running I would gradually push the choke in until it was almost off. If I pushed it in to off it would want to die. I would pull it out again and it would stay running. Now a few minutes later it dies. I start it back up again it runs for a few seconds and dies. I called my friend Lee as I thought I may have vapor lock from running for twenty minutes with the engine heat developing. I have fuel in the fuel bowl so he said can't be vapor lock. His thoughts are that I need to adjust the idle mixture screws and the fast idle as the carb is starved for fuel. I will try this next weekend. The carb is a Holley 2300 / 0-7448. As always I'm open to any and all advise. Have a great week all.

 

[Scoutboy74]

Often times an engine that wants choke to run when it should be warm enough to run without choke is experiencing one or more vacuum leaks. So double check for leaks.

 

[Rentalman]

Scoutboy74, thank you for the reply. Hopefully all that I need to do is retorque the manifold and carb. The only other source where vacuum could leak from is the hose coming from rear of carb to pcv valve to valley pan and all those items are new. I have hydro boost brakes so that elimates vacuum hose to brake booster. I think there are two vacuum ports at the rear of the manifold, 1/2" & 1/4" NPT that I have plugs in with Teflon tape. Thanks again for your advise.

 

[Scoutboy74]

Next time you have it running, you can spray carb clean around the base of the carb and intake, being careful to not direct any of the mist to where it could get drawn into the top of the carb. If the engine speed momentarily spikes with the spritz, you have a leak at that location.

 

[Robert Kenney]

Sounds a lot like a fuel supply problem. You should install a fuel pressure gauge and see what is being supplied to the carburetor. Vacuum leaks are usually not variable, like you are experiencing as it warms up it seems to improve then get real bad.
Another thing is that you could have a large vacuum leak through the PCV circuit as well. Block the carburetor port that supplies vacuum to the PCV valve and start it up, see if it improves.