Engine Need A Little Help

70mach395

Member
May 22, 2013
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Ok so Im stumped. I installed a 395 stroker in my 70 mach 1. It is 13.5:1 compression, so i set up the fuel system for e85 due to the amount of octane needed. When trying to start the engine for its initial start up and break in I could not get it to fire. The distributer is set at 10*. I tested the coil and found I had orange spark so I changed out the coil as a process of elimination. I then tried to fire it again and still got not much, just a little sputter but no backfires nada. I went ahead and pulled all the plugs and rechecked the gaps and they are all at .040. Adjusted the distributer some both ways. At 1 point I was able to get the engine to run for about 5 seconds if I held the throttle open about halfway. I have a petronix points conversion installed in the distributer. So my question is, where is the issue. The only thing left is to change the distrubter. Cap rotor and plugs are new, they came off my 351w that I just pulled out of the mach. They had less than 40 miles on them. Any thoughts would be great. The e85 is set up properly so its not a fuel issue. E85, carb, lines, pressure all new and installed.
 
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I havent adjusted it far enough to cause a bind. i was trying to avoid that. I installed it at tdc. I would be surprised if it was a tooth off. Even with a tooth off, every time I crank it I should get some sort of response from the engine, Backfire thru the carb, rough run, binding, something. Im mostly getting nothing or just a slight small fire after cranking it for long periods.
 
Are you getting fuel? Do you see fuel spray out when you open the throttle while looking down the carb?

You also need to make sure the distributor was installed at TDC on the compressions stroke. if not, it will try to fire on the exhaust stroke. You can pull the #1 plug, hold your finger up to it, and have a helper rotate the crank over by hand. Wait until you feel pressure coming out. Once you get pressure, the next time TDC rolls around on the timing pointer, it will be on the compression stroke. Last thing you need to do is pull out the distributor and reinstall it at the new TDC.

Also, this is probably the least likely, but you want to make sure your firing order is correct for you crank and cam. 351 based engines have a different firing order then the other Ford V8s.

Another possibility is that the pertronix conversions don't like being wired to the original ignition wire. The original ignition wire is a ballast resistor which lowers the voltage at the distributor. If you hooked it up to that, it could make for a weak spark. You need to verify it is hooked to a true 12 volt switched power.
 
Plenty of fuel going into and down the carb and a shot of starting fluid didnt provide any results. Im at work today so i wont be able to try any tricks until tonight. The petronix doesnt have a ballast in the circut, however i am still only getting 5volts to the positive side of the coil. The 351 ran with it that way. I did jumper 12v directly to the positive side and did not get any results still. Firing order is correct, I have a Comp cam "35" custom grind cam installed so the firing order is 351w for the 35 series. Tonight when I get home Im going to make extreme dist turn to the advance and see if I can get more than just a sputter. Ill also check tdc
 
I hate to ask this but I Chevy Silverado is a Flex Fuel truck. I`ve never ran flex fuel, is it better for the truck? I gathered from your thread that the octane is higher on E-85 which would be an improvement I think.
 
Ok after studying E-85 on wiki I found its 94 to 96 octane, which is good for hi end motors designed to run E-85, but for your average flex-fuel vehicle, you lose about 20% or more gas mileage running it.

I have a built 302 motor with 10 to 1 compression, what equipment has to be messed with to run E-85 in it?
 
Ok. E-85 is on average 105 octane. We use it in high compression motors for a few reasons. 1 its cheaper then buying racing gas. 2 it is more tolerant to detonation. 3 It acts as a partial cooling and cleaning agent. Fuel mileage sucks because it takes more E-85 to create energy. With that being said it means you have to have a special carb to run E-85, re-jetting will not solve it, it needs more volume, so bigger, fuel lines and a higher gph fuel pump is needed. Rubber made now days will resist E-85 and wont be a problem, however E-85 pulls water from the atmosphere so using corrosion resistant parts is a plus. Also it has de-natured alcohol in it so it acts as a cleaning agent, so over time all that crap built up on the bottom of your fuel tank will get sucked into your fuel filter. so use good non-paper fuel filters and expect to change them often when you switch to E-85
 
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Well still no luck. I checked tdc twice and ran 12v to the pos coil side. I moved the distrib a few teeth advanced and was able to run it barely as long as I gave it a little throttle. So I ll go after it a little more tomorrow after work
 
So heres a update. I have the cam card to the engine and its a doozy. It is a .633 lift with 272/280 with a 112 lobe seperation. So its a rowdy cam and is gonna idle rough as hell. I havent had a cam with this much lift before so last night what appeared to be bad timing was mostly rough idle. I have to set the idle on this near 1800 most likely to just get it running.