68 over heating after upgrades
06-12-2011, 09:51 AM
#1
Thread Starter
Join Date: Aug 2010
Location: texas
Posts: 22
68 over heating after upgrades
I have a 68 mustang coupe on which I recently had several upgrades done and now have an overheat issue. I have another thread on here concerning steam vent holes and heat. My car went back into the shop and had a head pulled to make sure the steam vent holes were drilled and we found that my block already had triangular shaped holes where edelbrock said to drill holes so that was not the cause of my over heat issue.
I had edelbrock heads installed as well as edelbrock matching cam. I already had a performer intake with 4v 500 cfm edel carb. I also have flowmaster dual exhaust with stock cast iron headers. Ignition is vac advance distributor with pertronics igniter. New plug wires. My radiator is over size copper 2 row 24x17 core with 6 blade 18” steel fan no clutch. The mechanic did put a restrictor with 5/8” hole in place of thermostat. I did have hi flow water pump installed when they did cam.
When I got the car back after upgrades it was running much hotter than before upgrades. I stalled a temp gauge with numbers and did test drive. In 4 miles I hit 210 degs with 95 outside and no a/c on. After idling few seconds went to 220 degs. I got gas at local store and headed back home. On the way turned on the a/c and when I stopped at my gate I hit 230 and shut it down.
I verified that head gaskets were on right and heads were on right. Then issue of steam holes came up. They did not drill holes so it went back to shop and found holes already there on my block. My block is C8OE. But for a week before it went back in I prowled the forums and talked to a very car savvy friend in Georgia. Forums said check gaskets, water flow direction, timing, mixture etc. One post said bleed air out of cooling system. I removed rad cap to check flow direction and had good flow at fast idle but noticed extreme air in system. Had foam coming out of radiator. So I warmed it up to 185 while massaging top rad hose and burping lots of air. I then let it cool down cranked it did it again. I did this 3 times total.
A couple days later I took it back to the shop to check for the holes. On the way there it was 80 outside, I left a/c off and drove 45 not over 50. The temp for 10 miles to town stayed at 175. When I hit stop light temp immediately went up to 180. I went through small town at 35 and then hit highway and went up to 55 mph. Temp stayed at 180 for 2 miles to RR track where I stopped and eased across. Immediately temp went to 185 and stayed there until I got to the shop 4 miles later.
Mechanic is installing hi flow thermostat in place of restrictor. And I asked him to verify timing and mixture.
So on the highway it was not bad after burping the air out but at idle it shoots up very fast. I don’t know how high it would have gone if I had to idle longer but it is worrisome that it goes up so much so fast. So I guess my question is should I put an electric pusher fan In front of radiator to help out in traffic or what? And if so does anyone know what amp the stock alternator is? I assume I will have to have a bigger alternator. If I do need new alternator what do you suggest?
All thoughts on subject appreciated.
I had edelbrock heads installed as well as edelbrock matching cam. I already had a performer intake with 4v 500 cfm edel carb. I also have flowmaster dual exhaust with stock cast iron headers. Ignition is vac advance distributor with pertronics igniter. New plug wires. My radiator is over size copper 2 row 24x17 core with 6 blade 18” steel fan no clutch. The mechanic did put a restrictor with 5/8” hole in place of thermostat. I did have hi flow water pump installed when they did cam.
When I got the car back after upgrades it was running much hotter than before upgrades. I stalled a temp gauge with numbers and did test drive. In 4 miles I hit 210 degs with 95 outside and no a/c on. After idling few seconds went to 220 degs. I got gas at local store and headed back home. On the way turned on the a/c and when I stopped at my gate I hit 230 and shut it down.
I verified that head gaskets were on right and heads were on right. Then issue of steam holes came up. They did not drill holes so it went back to shop and found holes already there on my block. My block is C8OE. But for a week before it went back in I prowled the forums and talked to a very car savvy friend in Georgia. Forums said check gaskets, water flow direction, timing, mixture etc. One post said bleed air out of cooling system. I removed rad cap to check flow direction and had good flow at fast idle but noticed extreme air in system. Had foam coming out of radiator. So I warmed it up to 185 while massaging top rad hose and burping lots of air. I then let it cool down cranked it did it again. I did this 3 times total.
A couple days later I took it back to the shop to check for the holes. On the way there it was 80 outside, I left a/c off and drove 45 not over 50. The temp for 10 miles to town stayed at 175. When I hit stop light temp immediately went up to 180. I went through small town at 35 and then hit highway and went up to 55 mph. Temp stayed at 180 for 2 miles to RR track where I stopped and eased across. Immediately temp went to 185 and stayed there until I got to the shop 4 miles later.
Mechanic is installing hi flow thermostat in place of restrictor. And I asked him to verify timing and mixture.
So on the highway it was not bad after burping the air out but at idle it shoots up very fast. I don’t know how high it would have gone if I had to idle longer but it is worrisome that it goes up so much so fast. So I guess my question is should I put an electric pusher fan In front of radiator to help out in traffic or what? And if so does anyone know what amp the stock alternator is? I assume I will have to have a bigger alternator. If I do need new alternator what do you suggest?
All thoughts on subject appreciated.
06-12-2011, 12:51 PM
#2
6th Gear Member
Join Date: May 2009
Location: PA
Posts: 5,232
A couple days later I took it back to the shop to check for the holes. On the way there it was 80 outside, I left a/c off and drove 45 not over 50. The temp for 10 miles to town stayed at 175. When I hit stop light temp immediately went up to 180. I went through small town at 35 and then hit highway and went up to 55 mph. Temp stayed at 180 for 2 miles to RR track where I stopped and eased across. Immediately temp went to 185 and stayed there until I got to the shop 4 miles later.
06-12-2011, 02:27 PM
#4
5th Gear Member
Join Date: Jan 2006
Location: Colorado
Posts: 3,946
If you have a C8 block then the holes that Edlebrock recommended drilling into the block are not there. The triangle holes that you mentioned are not the same holes they are saying need to be drilled. The triangle holes are directly centered between the cylinders. The 1/8" holes they recommend are off center from that. I went and looked at the Edlebrock instructions to be sure. That being said if you are running at 185 then I would say you don't have a heat issue and I would keep running it as is.
06-13-2011, 06:00 AM
#5
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
yep. 190 is ok. and the holes that need drilling are here:
you can use the head gasket as template (if you use the right one). edelbrock install manual describes the exact location
(this might be for a different head, but i don't know the eact part number of yours). check edelbrock website
see last page in this one:
you can use the head gasket as template (if you use the right one). edelbrock install manual describes the exact location
(this might be for a different head, but i don't know the eact part number of yours). check edelbrock website
see last page in this one:
06-13-2011, 08:07 AM
#7
2nd Gear Member
Join Date: Apr 2009
Location: Texas
Posts: 446
Just to toss this in the mix: I was running GT40 heads slightly modded, TrickFlow Stage 1 cam, and all new cooling system and was seeing variances in temps I just wasn't comfortable with. 220-230° were too common after a hard run and once it reached these, it was rare that it would settle back towards 190°. Not too bad, but not what I wanted to have to keep an eye on. I just finished installing a set of AFR heads, re-curved the distributor, added roller rockers and a couple other unrelated odd and ends. In the 30 miles after this, the temp has never crept above the 190° mark even though I KNEW it would have issues due to higher compression and aluminum heat transfer. Mine is a mid 90s block with factory steam holes. The only thing I can relate so far is the fact of my distributor recurve. Mine was begging for more timing - more than I thought. I went from the curve of 16° initial to 36° + ported vacuum to a curve of 25°/35° + ported vac. Before losing your hair, consider if your cam is timing hungry as mine was. It may be worth it to bump your timing up 5-10° and putt around - don't worry if your advance is high as long as you're paying attention and not letting it detonate. As long as you get no clatter, see if it helps your temp. IF so, a re-curve is in order.
06-13-2011, 08:51 AM
#8
Thread Starter
Join Date: Aug 2010
Location: texas
Posts: 22
I know 185 is good
and would be very happy with 185 to 195 but that was driving with no a/c on at 50 mph max with 80 degs outside. My concern was how the temp seems to shoot up so quickly at idle and does not come back down when i get back up to speed. I probably could have turned a/c on at speed and been ok but not at idle.
As for the vent holes my triangular holes are in the correct spot not between cylinders. I'll try to post pic here. This pic is not my block but is identical to mine. The holes line up with the drill holes in Edebrock gaskets.
As for the vent holes my triangular holes are in the correct spot not between cylinders. I'll try to post pic here. This pic is not my block but is identical to mine. The holes line up with the drill holes in Edebrock gaskets.
Last edited by jerthemost; 06-13-2011 at 09:08 AM.
06-14-2011, 03:42 PM
#10
Thread Starter
Join Date: Aug 2010
Location: texas
Posts: 22
Car is out of the shop
Got the car back today and here is the heating issue results:
steam holes were already there. installed new high flow t'stat not sure what temp will ask later.
From shop to home is about 20 miles. When i started it was at about 150 deg, had just been test driven, temp outside was 97, left a/c off. After 8 miles driving 55 stopped for light was at 195 deg. After 8 more miles at 62 mph got up to 209 still no a/c. Slowed for next 2 mi to 35 temp dropped to 200 still no a/c.
have not checked for air in system yet waiting for it to cool down a bit. i looked for radiator shops in my area and cannot find any. Was told plastic rads put them all out of business. If i can find one what do you think about cleaning and rodding and add 3rd core or should i just buy new aluminum rad?
steam holes were already there. installed new high flow t'stat not sure what temp will ask later.
From shop to home is about 20 miles. When i started it was at about 150 deg, had just been test driven, temp outside was 97, left a/c off. After 8 miles driving 55 stopped for light was at 195 deg. After 8 more miles at 62 mph got up to 209 still no a/c. Slowed for next 2 mi to 35 temp dropped to 200 still no a/c.
have not checked for air in system yet waiting for it to cool down a bit. i looked for radiator shops in my area and cannot find any. Was told plastic rads put them all out of business. If i can find one what do you think about cleaning and rodding and add 3rd core or should i just buy new aluminum rad?