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Discussion Starter · #1 ·
Let's get back to basics and see what's going on here.

Chev 265PP
305 heads (58cc)
Offy 360° intake
Edelbrock 1404 500cfm carb
1968 distributor (2 years old) w/ Crane Cam XRi pointless ignition

Only different things since I started the head swap was...
305 heads
Crane Cam XRi
spark plugs- different plugs set @ 35 gap

I started the head swap because of a blown head gasket I found while installing the XRi. Original heads looked as if valve recession was well on it's way, so I opted for the swap. 305 heads have slightly larger intake/exhaust valves. Both 265pp & 305 heads I believe are 58cc heads. The spark plug wires are over a year old and have been moved around alot because of valve adjustments.

Symptoms:
rough idle
rough slow accelleration
WOT accelleration seems just fine
seems to miss a little when just cruising at hiway speeds
jerky torque converter - lurches at idle

What are your thoughts as to troubleshoot this motor?
 

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Timing and vacumn would be where I would start. Got a vac gauge you can put on it? Thats the best way to adjust the carb. The slow bottom end screams timing ( to me at least ). How about engine temp.? higher now that before? Slow timing can make one run a little hotter. The good top end would be there even if timing was slow because of the mechanical advance picking the timing up. I would also open the plug gap to 45 since your running pointless. It should fire a lot hotter than points.
 

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Engine temp can easily be changed with a thermostat

I prefer my engines to run cool, makes them last longer, that's why diesals last so long they run cooler than gas engines.

Otis:)
 

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I would try another gauge. Where is the sending unit located? I have seen them in the intake and when the water is a little below the sender you get a false reading.
 

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Discussion Starter · #9 · (Edited)
This is a mechanical guage and I have double checked it with a laser thermal sensor. It is in the intake, and is in water, checked that too. I don't find this part of the problem as it ran fine before. I think I need to re-adjust my valves still, while it's running.
 

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Well if the temp is that cold with a 180º thermostat, it has to be bad. It would hold the water in the block until it reaches 180º. If you suspect the valves are too tight then by all means adjust them. Prolonged running will burn valves.
 

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Discussion Starter · #11 ·
I've tried 3 different thermostats by different manufacturers and all were the same.
 

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Discussion Starter · #13 ·
hahha most are stumped. Running down the road in the summer it's running about 160°. Idleing for 15 min. I have seen 205° but no higher.
 

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Some things to check with the xri. Hook the black/yellew wire to coil-. Hook the black/red wire to coil+. Make sure the ballist resister is working. According to Crane, if the xri module receives too much voltage, it will shut itself off to cool down. If you wire the xri according to the schematic in the instuctions, it will be wrong. Check and adjust if need be, the rev limiter on the module. Hope this helps you.
 
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