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Post by perearacing on May 4, 2014 9:31:45 GMT -6
Hey all, need some help figuring out a problem... I run a x mod race car (basically a b mod) 355 engine 9.5:1 compression, cast heads, cast intake, rochester 2 bbl carb. Took the car out for the first time last night with the new engine and damn it ran good...until about the 6th lap in when engine temps were at 260. Now i havent checked timing or anything yet since i am at work, but figure i would check on here and get some suggestions on what it could be. I'm running an FSR double pass radiator, no restrictor.. high flow water pump. What are some suggestions as to what it can be and to what i can do to bring my temps down?
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Post by new2dirt on May 4, 2014 9:46:57 GMT -6
Any gurgling/bubbling? Rad hoses hot on top and warm/cool on the bottom? Definitely check your timing. What are you using for coolant?
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Post by perearacing on May 4, 2014 10:39:42 GMT -6
No gurgling/bubbling that i noticed. Didnt think to check the hoses last night. and for coolant i had water/coolant mix and a bottle of water wetter. What should the timing be at? or around at least?
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Post by flipflopoo1oo on May 4, 2014 10:53:52 GMT -6
There is a lot of info in the archives!
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Post by flipflopoo1oo on May 4, 2014 11:08:45 GMT -6
There is a lot of info in the archives! Lack of fuel number one thing! To check this at anytime, take out number 3 plug (even a week later) and count the number of wet, oily threads from the seat back towards the spark end! Three is correct! Then look at number 8 plug and make sure it is not oiled all the way out! Too much fuel if burning in the exhaust can draw it lean like a jet engine! We run A/C plugs (R45T) that will melt first! Most (Quality plugs) will still be good even after melting everything else in the cylinder! Header glow or color change is a sure sign this is happening but just a flame in one tube in the collector is all it takes to lean out one cylinder to cause overheating! Restrictor needed maybe, depends on flue design! Fan design for rpms turned can be a factor! Distilled water works best with most! A fan cover is a must as is fan location to it! Check your oil filter for metal by pouring it out on white paper! I have always run a .066 350 and temps of any over 150 looses horses! I have used every cooling trick in the world to make it get down to 150 to gain horses! There are many from block choice to cam degree and oil PSI! Vacuum and extra fuel cools the best as you can produce horses and get it on down to 150 degrees! When you get it there it will frost over the intake on pump gas! If you use a restrictor, it will allow the pressure change to drop at the suction side of the pump and radiator to allow the heat energy stored in the coolant to release to the air passing threw! Like in refrigeration at a evaporator and not the reverse effects of a condenser on the high pressure side! A ungrounded mounting system can help this happen if the energy has no other option but to go to the air and not to ground!
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Deleted
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Post by Deleted on May 4, 2014 11:38:09 GMT -6
This should be easy. You have a double pass, good water pump and only a 9.5 motor. Well if the top hose isnt collapsing as mentioned above, and you dont have air trapped in the system, you need to remove your V belt reduction pulleys and install 1-1 Pulleys. With a good 4 blade fan and a halfway good shroud, you should be having trouble getting it to 200. Jack the car up in the front and remove the cap to let any trapped air work its way out to the high point. The reason reduction V belt pulleys dont work that great is the belts slip like crazy at RPM, so the 1 to 1 pulleys turn faster and compensate for the slippage and everything works as it should. If you can grab your fan and turn it, you belts are slipping, and no you wont be able to get them tight enough. I run a serpentine system at 25% reduction, but the fan has "0" slippage.
Dave
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Post by perearacing on May 4, 2014 11:41:59 GMT -6
Top hose collapsing could be a big part of it. and will be the first thing i change, i will also jack the car up and make sure to get the air out of the system. How can you tell if the pulleys are 1:1, i believe they are but i could be wrong.
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Post by Deleted on May 4, 2014 11:51:01 GMT -6
Measure across them, 1 to 1 are the same size across.
Dave
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Post by perearacing on May 4, 2014 11:57:31 GMT -6
ok awesome. thanks for the help guys, and if anyone has more suggestions keep em coming.... also will an oil cooler help any?
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Post by Deleted on May 4, 2014 12:03:34 GMT -6
Sure, but you only have a 9.5 motor. What RPM are you running? I used to run a 15 to 1, 383 at 7K with no oil cooler, and it was fine. Most of the time had hard time getting to 200. I run a cooler now, but we run a 18Deg motor at 9K, and its a totally different animal.
Dave
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Post by perearacing on May 4, 2014 12:07:36 GMT -6
We have to run a 7k chip and i tach around 6300-6800
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Post by street16 on May 6, 2014 13:25:12 GMT -6
I'm guessing that you are running an El Paso / Las Cruces X-Mod. This early in the season, the outside temps haven't topped 100 degrees yet, and 260 after just 6 laps - You have a problem. How hot was the engine before you started the 6 laps? I don't think reduction pulleys will cause the problem. I run reduction pulleys on my Super Trucks (same engine rules with a 4BBl and high rise) and they don't overheat in August. I would check the timing (I run 35-36 degrees @ 4000 RPM), make sure the lower radiator hose doesn't collapse (I use a flex hose with a spring in it), and then check to be sure water is moving - take the cap off and look with the engine cool. At this point, things start getting expensive. How old is the radiator? I've seen the caliche from well water plug up radiators and I've seen radiators that weren't drained over the winter have the cores swell up so much that very little air flows through them. How many PSI cap? How much water did you lose? Pull the valve covers, and look for signs of water. I don't know if you build your own engines (I do), but compared to the price of replacing an engine, oil and gaskets are cheap. If you're getting water in the oil, you're looking at a cracked block or an intake issue. If it's a blown head gasket or cracked head you will have a really clean piston (compared to the others) - might be hard to tell with a brand new engine. I hope it turns out to be something simple - and cheap. I forgot the obvious - flex fans don't work on race cars, so if you're running one ditch it.
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Post by perearacing on May 6, 2014 17:28:14 GMT -6
I'm guessing that you are running an El Paso / Las Cruces X-Mod. This early in the season, the outside temps haven't topped 100 degrees yet, and 260 after just 6 laps - You have a problem. How hot was the engine before you started the 6 laps? I don't think reduction pulleys will cause the problem. I run reduction pulleys on my Super Trucks (same engine rules with a 4BBl and high rise) and they don't overheat in August. I would check the timing (I run 35-36 degrees @ 4000 RPM), make sure the lower radiator hose doesn't collapse (I use a flex hose with a spring in it), and then check to be sure water is moving - take the cap off and look with the engine cool. At this point, things start getting expensive. How old is the radiator? I've seen the caliche from well water plug up radiators and I've seen radiators that weren't drained over the winter have the cores swell up so much that very little air flows through them. How many PSI cap? How much water did you lose? Pull the valve covers, and look for signs of water. I don't know if you build your own engines (I do), but compared to the price of replacing an engine, oil and gaskets are cheap. If you're getting water in the oil, you're looking at a cracked block or an intake issue. If it's a blown head gasket or cracked head you will have a really clean piston (compared to the others) - might be hard to tell with a brand new engine. I hope it turns out to be something simple - and cheap. I forgot the obvious - flex fans don't work on race cars, so if you're running one ditch it. Same rules as EP and Cruces but race in grants, nm. when i went onto the track the engine was at about 140-150. Im definetely gonna have to check timing, Im thinking maybe the top hose was collapsing a little. The radiator is older and will be changed. When i checked the water it was still full. I still havent had time to even pull the car outta the trailer yet but once i do i willcheck all these things and post up on here and see what everyone suggests by my findings.
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Post by moldy on May 13, 2014 17:36:01 GMT -6
Make sure to run a shaker screen, if not build one, use it. Sucks to have a cool car on a good track, only to run hot with clay stuffed into your radiator.
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Post by Krooser on May 16, 2014 21:44:31 GMT -6
Check to be sure that radiator is clean… some guys here actually run a paper furnace filter instead of a shaker screen. Toss it every week if needed. I may try this this year.
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