Engine bay heat managment

[Jonnh]

Hi im after anyone's thoughts advice thoughts on reducing heat in the engine bay and benefits gained . With the carbs being above the exhaust manifold there must be a lot of heat generated. I was thinking of wrapping the manifold and probably try and duct the air in better ,also on a recent car show seen a lot using the heat tape .My engines modified running twin 45's with a tubular manifold ,thanks in advance

[Sutty2006]

I’ll be honest, I don’t think you need to worry too much. You can heat wrap the manifold if it’s in good condition as best you can. Make sure you have adequate cold air feed through the offside pipe ducting too and pointing in the direction of your air filter.  But while you are driving cold air is forced into the engine bay anyway so heat soak isn’t a problem unless you are stationary for a long period of time. 

[Jonnh]

22 minutes ago, Sutty2006 said:

I’ll be honest, I don’t think you need to worry too much. You can heat wrap the manifold if it’s in good condition as best you can. Make sure you have adequate cold air feed through the offside pipe ducting too and pointing in the direction of your air filter.  But while you are driving cold air is forced into the engine bay anyway so heat soak isn’t a problem unless you are stationary for a long period of time. 

Thanks Steve

[H-400]

Had problems when idling for a longer time (when I used those DCOE's) in traffic jam's.  Cause of the heat the idling rpm's went up but solved this with heath wrap around the exhaust and a heat shield between under the carbs. 

[611]

6 hours ago, Jonnh said:

Hi im after anyone's thoughts advice thoughts on reducing heat in the engine bay and benefits gained . With the carbs being above the exhaust manifold there must be a lot of heat generated. I was thinking of wrapping the manifold and probably try and duct the air in better ,also on a recent car show seen a lot using the heat tape .My engines modified running twin 45's with a tubular manifold ,thanks in advance

Like Herman, i used to get this on mine when i ran twin 45's. Im not sure what issue you are getting but i used to find when you got stuck in traffic for a long time and it was just idling, that im sure it got hot enough to start evaporating the fuel in the carbs and it would run very rough and you needed to rev it. I wrapped the exhaust and that helped a little but its the actual heat getting stuck in the engine bay. I cured mine by fitting a small computer server fan (they are 12v) with an duct to vent it externally and this really helped. I had it so i could turn it on myself, then later hooked it up to the kenlow stat so that it came on when the main fan came on to blow cool air in the little fan was blowing the hot air out, worked a treat. I now have throttle bodies with injection and that doesn't suffer the same but i replaced the kenlow with 2 smaller fans that they use on RV's in the US and that seems better than one big fan as they are about the size of the grill intake so seems to get more cool air in. 

Mine is the A series so might be slightly different from yours? 

 

Andy

[®evo03]

Ceramic coating on manifold. 

Heat shield.

Plumbers heat mat, a blow torch can even burn it. 

Vents 400 bonnet, most importantly, a electric fan. It will cool even with 30°C air temp. 

Cabin heater, up full heat, and blower on full, windows down, doors open 🤣

Edited May 23, 2023 by ®evo03

[611]

10 minutes ago, ®evo03 said:

Ceramic coating on manifold. 

Heat shield.

Plumbers heat mat, a blow torch can even burn it. 

Vents 400 bonnet, most importantly, a electric fan. It will cool even with 30°C air temp. 

Cabin heater, up full heat, and blower on full, windows down, doors open 🤣

I did think about a leaver you could pull that lifted the bonnet up, that would get rid of the heat!!

[Metalbasher]

I’ve had my tubular manifold ceramic coated by Zircotec, they claim 15% heat dissipation reduction, with higher values with higher level coatings. Bad news is I’ve not yet tried it in anger but aesthetically it’s very good. Exhaust wrap is ok but can look messy over time or hold water if lower down the exhaust system

[611]

20 hours ago, Metalbasher said:

I’ve had my tubular manifold ceramic coated by Zircotec, they claim 15% heat dissipation reduction, with higher values with higher level coatings. Bad news is I’ve not yet tried it in anger but aesthetically it’s very good. Exhaust wrap is ok but can look messy over time or hold water if lower down the exhaust system

I thought about the ceramic coating until i got the quote!! I did have exhaust wrap and as you say, starts off nice but doesn't fair well over time.

[Metalbasher]

Quite true, I haggled a bit and just had the two branches coated (leaving the 2 into 1 pipe VHT painted) and it wasn’t too bad. I haven’t tried it yet as mentioned so can’t comment on its effectiveness 

[Jonathan Pounsett]

When you’ve wrapped the manifolds you can give them a good few coats of clear ultra high temperature paint. This keeps it all in place and stops muck getting trapped in the weave. 

[H-400]

You wrap the heat wrap wet around the exhaust manifold, when it dries it fits tight and as Jonathan wrote I gave it a few coats of paint. I bought it as a set with the rattle can high temp. paint. Did this also with my other engine, it gives your exhaust gasses a better flow as also ceramic coat does:

I used also some clamps to be sure everything stays on its place:

[611]

10 hours ago, H-400 said:

You wrap the heat wrap wet around the exhaust manifold, when it dries it fits tight and as Jonathan wrote I gave it a few coats of paint. I bought it as a set with the rattle can high temp. paint. Did this also with my other engine, it gives your exhaust gasses a better flow as also ceramic coat does:

I used also some clamps to be sure everything stays on its place:

Now your just showing off with your engine, Herman 🙂

[mantasrme]

With ref to heat wrapping manifolds. I found painting the manifold first with heat paint before wrapping, and then painting the heat wrap gave the best protection. First one i did i just wrapped and it didn't last long at all. Second one i wrapped and then painted and it lasted well but the manifold under the wrap started to get surface build up when its sat around. Paint first protects the manifold longer, easier to do with a mew manifold thats good metal though.

Oh and i'll ask my mate who he uses for coating his customers manifolds. He's a TVR specialist and has all the manifolds and collectors done on his rebuilds as they produce huge heat in the cramped engine bay wrapped around those V8's. Make a big difference to underbonnet temps he finds.