engine noise

[cjoenny89]

ok bare with me while I try to explain this situation and the noise. finally got the old girl on the road and running good. To me this is normal because I have not road in this truck for 27 years. (41 now)
back 27 years ago my dad and my brother rebuilt the old 327 and my brother had a 350hp cam out of a 350 chevy engine that they put in there not sure if this it the true specs but this is what they tell me lol.
My dad 81 swears that the engine roars now and is not the quiet thing it used to be. It is very loud in the cab while driving and yes we just had all the exhaust redone and that helped a lot. It almost sound like the fan is roaring?
This is very hard to explain. while it is sitting there it isn't as noticeable but when you take it for a ride you really have to elevate your voice to get over the sound of the roaring engine. Does this make since to anyone? It almost reminds me like you have your head under the hood with the engine running at high idle. Any suggestions? Do we have the fan assembly in correctly? Possible vacuum leak? (runs great idle and down the road). Or is this how it is going to be with this 350 magnum cam? I remember now its a 350 magnum cam that came out of a speed boat.

by the way this truck is way to much fun!!!!!

[hamjet]

What type of fan blade do you have? if its a flex blade fan, get rid of it. that was 90% of the noise on mine. also, people get too use to todays vehicles with over insulation, overdrive transmissions, etc. and when they get behind the wheel of the older trucks they seem very loud. The cam won't make it louder. It's been sitting for a while, is there any chance there are rust holes in the firewall or the floor pan? just a few things to check...

[cjoenny89]

No rust holes its been all fixed! The fan blade is factory. Gramps bought it new in 68 dad got it in 84 and tore it apart in 87, engine got a rebuild in 88-90 and sat for all these years with just getting started now and then. I know its going to be louder then the new trucks but I don't recall having to talk so loud to have a conversation while driving. I will say there is no floor isulation just a carpet kit.

[cjoenny89]

Here is Dad while we waited for my son to get done with football practice last night on its maiden voyage!

[cleszkie]

Are you running glass packs, chambered mufflers (ie Flowmasters), or some sort of turbo mufflers? This will make a big difference in exhaust noise tone and volume. Also, are you running a manual or auto tranny? Noise could be coming from an auto tranny going bad. Lastly, maybe a dumb question, but do you know if you are running a timing chain or timing gears? If you have timing gears, there will be a very noticable wining noise that increases with RPM. Just some things to consider.

[GASoline71]

Fixed blade stock fans are loud.

Gary

[cjoenny89]

This is a stock 1968 truck and 327 engine other then .030 over rebuild and new cam.
Truck only has 47,700 miles on it family owned since new has sat since about 1988.
I do not think it is tranny noise only because you get the same noise only not as loud when it is just sitting there. It was really bad before we changed carberators the Quadrajet had a huge vacuum leak that made it sound and run funny but we had other issues also but those are now fixed. It is almost like a huge woshing air sound. Maybe I will start with the fan. I am not sure with the muffler it was there before we started and muffler man said it is still good. Only thing is its dumps out behind the cab on drivers side about half way to rear wheel. Noise seems to be from engine compartment. Could it be the heat riser? Just had that gasket replaced also. Can I un-hook the fan and try that for a short time to see if it is the fan?
Thanks

[GASoline71]

Yep... you can take the belt off of the water pump and run it for a tad bit to see if the fan is making the noise.

Your exhaust won't make a "wooshing" sound if it is leaking from the heat riser. I would just tick loudly and sound like crap.

Gary

[Redline novdog]

I was gonna suggest what gaoline71 said, only take the fan off and bolt the pulley back down. run it for a bit ( don't let it overheat!!!!).Does the noise go away??

[Stocker]

You say the fan is stock but that doesn't tell us if it's a fixed-blade fan or a clutch fan. Post up a pic.... If it's a clutch fan, the clutch unit might be seized and that will certainly make it roar loudly.

[Fitz]

Originally Posted by Stocker

You say the fan is stock but that doesn't tell us if it's a fixed-blade fan or a clutch fan. Post up a pic.... If it's a clutch fan, the clutch unit might be seized and that will certainly make it roar loudly.

Good advice. Remove the belt and see if it quiets done. A minute or two won't hurt your engine.

[cjoenny89]

At work I will check in a few hours

[cjoenny89]

Here is the fan looks solid I didn't have time to run it without the fan or belt off.

[Stocker]

That's a factory fixed-blade fan. It shouldn't sound any different than it did 27 years ago, but they do pull air all the time, so there's somewhat of a roar. If it were mine, I'd install a clutch fan for better cooling, quieter operation, and less power loss. Just my 2 cents....

As to the noise, either there's another problem, or Dad's memory (or hearing) has changed a bit over the years. Or maybe he used to putt around at low RPM and you're revving it higher?

[cjoenny89]

It is hard to say I am sure it is a little of both hearing and memory! lol Love that old guy and wouldn't change it for the world. I just don't like how loud it is in the cab I feel we have to almost yell to talk while driving. maybe I will try to take a video and post it and see if you guys think it is normal. And yes I tend to run it a little harder then he did I am sure!

[yuccales]

Originally Posted by cjoenny89

Here is Dad while we waited for my son to get done with football practice last night on its maiden voyage!

Great looking truck.

[jjzepplin]

Great looking truck for sure! Is your exhaust heat riser functional? Over the years I had one seize closed and it was plugging the exhaust. Sounded like someone put a potato in my pipe.