Bikertrash3531

I met with the previous owner of my runner and he informed me of a broken bolt in the thermostat housing and gave me another intake for it. Its dirty and what not and was wondering if there is a coating of some kind in the runners that will make it harder to have it glass blasted to clean it up?

Thanks.

abecedarian

No. It's a cast piece and should clean up well with chemical solvents and maybe a brass brush. Hot tanking may help remove stubborn deposits. Walnut blasting should do okay without doing any damage to the runners.

If you're looking to polish it, no particular reason to do so: gasket matching upper to lower, and lower to head is more than enough for a little extra power.

The upper plenum generally only carries air and some exhaust if the EGR works, and maybe some fuel during cold cranking. And you shouldn't have any problem with fuel puddling with cold starts that since the cold start injector should turn off immediately after the engine is running and you release the key.

The lower manifold carries the air (EGR gasses and minimal fuel as mentioned above) from the upper manifold to the head, and fuel from the injectors to the head, which is only 1-2 inches so again, no particular benefit from polishing, particularly as all the injectors fire at each engine revolution so puddling will happen, particularly at low engine speeds.

Bikertrash3531

Thanks for the reply but im afraid it was a little too late. I went ahead and had it blasted. I must say the results are great.

I think it will perform better than it did. There was about an 1/8" of gunk in the runners that promted my original question. The guy who did it said he used a lower pressure setting and a fine sand to do the job.

abecedarian

Let us now how it does.

Bikertrash3531

Will do.