Crossover or circ pump
#1
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Joined: Apr 2005
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From: St.Peters,Mo/5mm LOTO/LEOPA
I am sure this has been debated over and over. I dropped my engines off this past weekend in Michigan to be rebuilt. They are stock carb 502. I am looking for 550+ hp. I am ditching the quadrajunks and getting intakes and carbs. I need new thermostat housings and want to replace circulating pumps. So I thought abought crossovers . More bar room talk than any but some think the circ pumps would be the way to go. Has there been any "real" world problems on a lower hp engine running crossovers?
#7
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From: Between A Womans Leggs in IL
when you run a crossover the engine tempiture is more in the back of the block compared to the fromt of the block..when i run a crossover i will run a -8 hose from the rear intakes water ports(if none you have to drill and tap some in) this will relieve some of the heat that builds up on the rear of the block..i like to run circulation pumps,,it moves the water around in the block and keeps a more constant temperture in the block and cylinders heads and with a cross over they tend to shock the block,esplically when your boat leaves the water and re/enters,,what ever pressure slips by the sea pump map blow gaskets from all the pressure..
#8
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Joined: Sep 2012
Posts: 80
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From: Lake Winnebago
when you run a crossover the engine tempiture is more in the back of the block compared to the fromt of the block..when i run a crossover i will run a -8 hose from the rear intakes water ports(if none you have to drill and tap some in) this will relieve some of the heat that builds up on the rear of the block..i like to run circulation pumps,,it moves the water around in the block and keeps a more constant temperture in the block and cylinders heads and with a cross over they tend to shock the block,esplically when your boat leaves the water and re/enters,,what ever pressure slips by the sea pump map blow gaskets from all the pressure..
Could you post some pics or a diagram of this set up? I'm running crossovers and have scuffed #7&8 pistons. I thought it was cold seizure but we did pick up some weeds one weekend that ran the port motor hot before I noticed it.
#9
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Love to see a pict of that as well Fixall.
My rig runs super cool with the crossovers. Ive never had anything like a "cold" problem.
Back cylinders may run a few degrees hotter than the fronts, but the whole thing runs way cool anyway -
This consistently runs with the water temp at 100/110 oil 100-140 at a continuous- 6K (90MPH) for 20 minutes straight- till you drain a side tank dry.
Will run for a decade like this before a rebuild with nothing more than standard tune ups and regular oil changes.
UD
My rig runs super cool with the crossovers. Ive never had anything like a "cold" problem.
Back cylinders may run a few degrees hotter than the fronts, but the whole thing runs way cool anyway -
This consistently runs with the water temp at 100/110 oil 100-140 at a continuous- 6K (90MPH) for 20 minutes straight- till you drain a side tank dry.
Will run for a decade like this before a rebuild with nothing more than standard tune ups and regular oil changes.
UD
Last edited by Uncle Dave; 01-18-2013 at 08:39 PM.





