So a while back I replaced my blown up 305 tpi with a carbed (650 edelbrock AVS2) 350 H.O. crate motor (the 300hp version the 217 heads instead of the vortecs, same as l98 iron heads). When I first put the car on the road during february I used to be able to run 87 just fine in the car with no pinging, and with a 180 thermostat and 185 fan switch It would never go above that. Once the weather got warmer I noticed it got worse and worse to the point where even 93 was an issue, I used my timing light to set the initial timing to 8 degrees and with my street fire MSD distributor (8632) that should be around 30 degrees of total timing at full advance, definitely conserative enough to at least run 93 right? anyways... it was at this time I also started experiencing some serious cooling issues causing the car to boil over a time or two. I originally had the dual fan setup but the right fan was lunched so I pulled a single fan and shroud out of a donor car basically for free and swapped it over, swapped to a 160 thermostat and added a secondary pusher fan in front of the condensor that supposedly flows "1600 cfm" even though it barely feels like its moving anything, now it slowly climbs to 220 and either stays there or climbs even higher if I have the AC on, which works great btw, I converted to r134a and added a new condensor, only issue with it is that it cooks my motor alive with it on so I cant even use it, it might as well just not even be there.


I have a few ideas:

1. A couple of days ago I tried putting in an adjustable vacuum advance pod and gave it manifold vacuum. With it connected to manifold vacuum It was hovering around 180 and would occasionally go to 200 if I was in heavy traffic, great! I thought I fixed the issue.. however if I tried to go WOT the engine would sound like it's rattling itself apart (this is still with 30 total advance theoretically). I kinda suspect my timing light is messing with me since this is my third harbor freight timing light and each one that I own seems to give me a different reading, I have no idea what my total timing is at since when I try to bring the RPMs up with the light connected, the light basically shuts off and stops reading at anything above 1500 RPM. ever since then I reset everything, put the original vacuum pod in and left the advance disconnected in hopes that would do something, after all that's what GM performance parts SAYS to do with this motor, leave the advance pod disconnected. Could this just be a dumb tuning issue?

2. The radiator is a stock replacement brass unit from "The Radiator Factory" (???) I can't seem to find any info on them. I run my 700r4 through there with no auxillary cooler. maybe this is just a poorly designed unit?? Idk, it was literally BRAND new when I got the car so I decided to run it. should I just go ahead and replace it with those 3 core radiators?

3. I did end up installing a stock single fan from another car and used a cheap amazon pusher fan for the condensor, could this just be a simple airflow issue? taurus fan time? (air dam is in place, does kinda make a difference at highway speeds with current setup)

I personally feel like this is multple issues at once causing it to be really bad as of current but I'm not too familiar with how the cooling systems work in these cars, any ideas would be great, this is my DAILY and my only car!! I need it to survive lol.

 

Regardless of what your timing light is telling you, back the timing off until the engine no longer pings; otherwise, you're risking severe engine damage.

Additionally, some of those cheapo chinese fans move far less air than they claim.

 

350 Chev engines do not normally run Hot. 350 with 300 hp in my old chevelle never ran hot & had just a stock fan. All stock hardware 1970.
Why not try going stock. Remove the MSD unit & go back to a stock distributor.
It almost sounds like the MSD if advancing your timing way to much. Too much advance will definitely cause the engine to run hot

 

I agree, with 72buickgs. Replace the MSD unit with a GM performance parts piece. I have heard of issues with MSD units.

Good Luck,
Fred

 

Toss the MSD components and just get "stock" replacements. Set the timing and see if that fixes it.

 

I hooked up my light to see what it was actually doing given the setting it was at, 12 degrees, according to the distributors instructions it's supposed to have 22 degrees of mechanical advance, which would give me 34, exactly what im looking for. Of course being an MSD product it's WRONG, it read 40 degrees advance total with a real timing light, HOLY ****.... Anyways I set my total at 32 degrees and my initial timing ended up falling at 4 degrees initial. It doesn't get above 190 with the AC off, with the AC on it will barely creep past 210 sometimes but wont go any higher during heavy traffic and when I start driving it comes back down to 195-ish range. Seems it's fixed now, I'll give updates if any but it looks like the mystery is solved so far, my engine seems way more responsive and I have my vacuum advance hooked back up to ported the way it should be.

 

Awesome! Glad it’s fixed. The foothold that MSD has in the market it wild. Stock-type dizzy components work great for a wide range of applications, plus keeps maintenance a bit simpler.

 

If you have trouble again OSC951radiator on rock auto $86 its two row. Then for a fan get Corolla dual fans or LS1 fans or the big taurus fan. 180 Thermostat and 89 turbo trans am fan switch and life should be good.

I prefer vacuum advance hooked directly to manifold.

 

Same! Couldn't imagine going back to ported.