Will not start when its hot?
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Will not start when its hot?
I just rebuild a 289 block and put rebuild 302 heads on top. I have two questions for any input. First I set the timing to TDC then I tuned the carb until I achieved about 19lbs of vacuum. Then I turn the car off for about 3 seconds. Then it restarts. If I let it sit for a couple of mins. It will not start. Unless I use starting fluid in it. The idle RPM's are set at 750. The motor starts when it is cold but not when it’s hot. Any ideas to what could cause this.
Also I have pedestal rockers and I was told that with out a stud they are non adjustable. So I toque them down to 20lbs I am still getting about 1/4 of an inch of play in them I put 302 push rods in it with 289 lifters. And I put the old rockers back in. Could the rockers have that much wear on them? And has anyone else done this setup before?
thanks for any input
tweakingit
Also I have pedestal rockers and I was told that with out a stud they are non adjustable. So I toque them down to 20lbs I am still getting about 1/4 of an inch of play in them I put 302 push rods in it with 289 lifters. And I put the old rockers back in. Could the rockers have that much wear on them? And has anyone else done this setup before?
thanks for any input
tweakingit
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From: Huntersville
I (think) that the 289 and 302 used different pushrod length depending on the year. Some, maybe all, not sure, 289's used slotted holes in the head to act as a guide plate for the pushrods. This type head did not use the rail type rockers to keep them aligned.
As far as not starting hot, it could all be related to the pushrods holding the valves open but I kind of doubt it.
Have you broke the cam in? You need to do this on a new cam.
Sorry for not be much, if any help.
Clint
As far as not starting hot, it could all be related to the pushrods holding the valves open but I kind of doubt it.
Have you broke the cam in? You need to do this on a new cam.
Sorry for not be much, if any help.
Clint
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How long does it take to break the cam in? and could putting adjustable rockers in help tighten everything up? Like changeing them over to studs instead of the pedistal rockers. the heads are a hole not sloted. Should i install a guide plate for the rods? thank you for any help i am stumped.
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From: Huntersville
This is over my head but since no one else was chiming in I thought I'd try too help. Breaking in the cam is keeping the rpm's up at around 2500 rpms for anout 25 to 30 minutes without overheating the engine.
Adjustable rockers might solve your problems but you still need to make sure the rocker rollers are staying put near the center of the valve tip and not too close to the edge. You have to run guide plates and hardened pushrods with non-rail type roller rockers. Plus the head needs to be machined for the guide plates and studs.
But, check with Crane Cams and CompCams about it. In fact Compcams has some good info about it all on their website. I think there are some kits out there to run roller rockers and guide plates without machining the heads.
I hope some more knowledgable people will chime in and help you out. If not check out the FordMuscle web site. There are some smart people over there on small block fords
Clint
Adjustable rockers might solve your problems but you still need to make sure the rocker rollers are staying put near the center of the valve tip and not too close to the edge. You have to run guide plates and hardened pushrods with non-rail type roller rockers. Plus the head needs to be machined for the guide plates and studs.
But, check with Crane Cams and CompCams about it. In fact Compcams has some good info about it all on their website. I think there are some kits out there to run roller rockers and guide plates without machining the heads.
I hope some more knowledgable people will chime in and help you out. If not check out the FordMuscle web site. There are some smart people over there on small block fords
Clint
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From: Still under the hood in O
Crane does make a stud/guideplate conversion, the part is 36655-16. Summit part # crn-36655-16. Cost about $90.
I really don't think this will fix your problem. I converted to this because I had very low compression from the valves hanging open. It was a geometry problem from the new cam. It started and ran fine in spite of the hanging valves with no trouble. You will benefit from the conversion no doubt, but I don't think it will solve your hot start problem.
You said it starts when you use starting fluid. How close is the fuel line to the exhaust? Is the carb new?
When it does this, look down the carb and pump the gas to see if it is getting fuel. The floats could be hanging.
I really don't think this will fix your problem. I converted to this because I had very low compression from the valves hanging open. It was a geometry problem from the new cam. It started and ran fine in spite of the hanging valves with no trouble. You will benefit from the conversion no doubt, but I don't think it will solve your hot start problem.
You said it starts when you use starting fluid. How close is the fuel line to the exhaust? Is the carb new?
When it does this, look down the carb and pump the gas to see if it is getting fuel. The floats could be hanging.
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From: Still under the hood in O
I just reread you post. What is your timing set at? If you have it set at 0 deg BTDC you are way too retarded, the timing that is :-)
What does the motor sound/act like when it doesn't start?
Set it at 10 deg BTDC and try again.
What does the motor sound/act like when it doesn't start?
Set it at 10 deg BTDC and try again.
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