VH overheating problem

[Hipstar]

Hi all I have a Vh ss with a 355 stroker, cvr electric waterpump, 3 core alloy radiator, thermo fan, cast vn heads decked and ported, harrop manifold and a 750 aed holley.
Now in winter the car isn't much of a problem but as soon as we get a warm day she gets hot and the only way of cooling down is to pull over and let the thermo run while the engine is off. The carby hasn't been tuned but was bought for the specs of my engine but could that be my main problem or I was thinking if the electric waterpump could be pumping too much water through the radiator and not have enough time to cool. I have tried just water to lots of coolant different temp thermostat but not much changes. Once it gets hot around half the thermo can't bring the temp down but if it sits on 1/4 there isn't a problem. So any ideas what I should do would be great

cheers

[ari666]

how is your vac advance rigged up? believe it or not that will cause it to run hot.

[VK SL 3800]

How far is she bored out? When taken out a fair way you can start getting cooling problems from the cylinder not being able to retain enough heat until the exhaust valve opens and then it puts extra pressure on the cooling system and it cant cope. Could be your water pump, you can push water through both engine and radiator so fast it has not got enough time to collect the heat in the engine (very unlikely) and then dissipate heat through the radiator (more likely). Running to lean will cause it to get hot, get it tuned properly that could help. At around 3/4 on the gauge (stock gauge, and i say around as they all read slightly different for the same temperature if that makes sense) is about 100 degrees c.

[karlos]

Are you running a thermostat,if so which one?

Are there thermo fan probes being used for optimum use(stop heatsoak ect),also is a waterpump controller being used to stop the flow and letting it sit in the radiator longer.

Is the thermo fan shrouded,if not then get that fixed ASAP.Twin EF-EL thermofans are killa.If its a single 16" item them be very smart in shrouding it,make the most of the setup.

Short of all this put the stock clutch fan setup back on if you find yourself getting knowhere,it might not look as good but it works bloody good imo.

[180sc]

ford mondeo twin thermos are a better fit then the falcon ones and do the job nicely, its not an uncommon problem when running thermos on holden v8's which is why holden kept the engine driven fan for so long.

[Darren_L]

ditch the thermo fans, can't beat the old engine driven clutch fan.
It will outflow any thermo fan combo you can fit under the bonnet

[Hipstar]

Thanks for the replies!!
Ok I don't know how far it has been bored out but I would of thought the previous owner would of gone the 60thou. I'm using an msd setup and that is using the standard weight and spring settings it came out with. I am using a thermostat I have tried a couple of temps I'm running a 90deg and no I'm not using a controlerwhich I have thought about. I have the 16" single thermo with shrouding. Yeah I'm trying to keep the engine bay as clerk as posible as there is nothing in the engine bay that doesn't have to be there.
Thanks for the help I'll have a play and see what I can come up with
cheers!!

[ari666]

I'm using an msd setup and that is using the standard weight and spring settings it came out with.

yeah nothing to do with mechanical advance. vacuum advance works on part throttle, so when you are cruising around at 2.5-3k rpm. if it is not hooked up it means that part throttle its running too far retarded (base timing) and starts running a bit hotter. the problem is that once the temp has gone up, its difficult to make it go back down again so it continues to rise and add a thermo fan to the equation which will struggle to cool it at the best of times, itll cook.

[Hipstar]

Point taken which is spot on what's happening so I'll book it in for a dyno run and get rid of the thermo and electric waterpump to clear any reason for overheating. Guess just go back to basics if it doesn't work

[ari666]

hope your dyno guy can figure it out, this thing sounds like itll be a bit of a weapon