It all began with my 455 overheating on the highway (3000rpm, 230-240 degrees)
When I slowed down it would take a while but temperature would drop.
There was no oil contamination in the sump (Cappuccino fizz look)
None was being burned out the exhaust both tail pipes had carbon inside and didn't have the steam cleaned look.
I changed the antifreeze water mix to straight water since the coolant would get polluted with brown froth and have a dirty look.
I replaced the stock 3 row rad with an aluminum 3 row and dual electric fans. It still would overhead at higher rpm and started to get worse.
I removed the heads and found it had OEM steel shim head gaskets but no sign of leakage. Since this turned into a Might As Well type project I also removed the water pump which had an aftermarket 6 blade stamped fan compared to the aluminum GHB 8 blade stock volume replacement I was going to put in it's place.
I am replacing the cast iron intake manifold for an Edelbrock 2151 performer.
The stock manifold was sealed nice and somebody put RTV on the water ports/manifold turkey tray gasket I found inside. I still have to remove the timing chain and camshaft.
So any ideas what to check while it's apart regarding the coolant leak???
- I 've got to pull the Hydraulic lifters and bought a slide hammer lifter remover tool used....it doesn't hook up to the top of the lifter to pull it.....Am I missing something?
-So far nothing has come up to explain the overheating and water contamination.????
The engine oil showed no coolant contamination
Thanks
joepenoso

 

I can usually pull lifters out with a needle nose pliers attached to the spring clip on top. Sometimes they need to be persuaded up and down if there is varnish build up. If your lifter bottoms are concave take a serious look at your cam

With your coolant turning brown I'm leaning towards a head gasket. Which also would explain your temp creeping while driving and cooling down at lower speeds.

 

Thanks
I rebuilt a few motorcycles but have no 1st hand experience with hydraulic lifters
joepenoso

 

I agree, that if your antifreeze is turning colors that you may have a deeper issue. I was having an overheating problem last summer. Turned out that at higher rpm, my radiator hose was sucking itself closed. Low rpm, it would maintain a normal temperature.

 

Re: Overheating & Hydraulic lifter slide pull remover

I went back and used needle nose pliers and they came right out. Judging by their condition they were new.........unlike the timing chain that had an inch of slack in it. I was so consumed in getting the slide hammer lifter remover to work that I didn't do the obvious. Still that brown coolant pollution and overheating has me worried. I currently have two puller shrouded electric fans, aluminum 3 row radiator and a spring in the lower rad hose.
Do I need to remove the distributor in order to take out the cam?
thanks

joepenoso

 

+1 (or 2).

If your head gaskets were definitely good, that starts you thinking Bad Thoughts about cracks in the block.

- Eric

 

Yes - but you have to remove it for the intake anyhow!
While off, get the heads magnafluxed - have them check the valve seats!
After all this work, it sounds like a minor crack - if it still happens, use a can of Bars Leak, and forget about it!

 

Yes, the distributor needs to be removed to remove the cam.

X2 on getting the heads done.

 

Thanks I removed the intake/ heads without touching the distributor. The heads that it came with are being replaced with "C" with extended centre exhaust port walls and closed intake/exhaust heat under carbs crossovers. So that should eliminate another possibility. Thanks for your help sometimes you overlook the obvious when doing things for the first time and being in a rush
joepenoso

 

No problem, it's always good to bounce ideas around.

 

I pulled the camshaft out and guess what...... it was a generic#916 GM 455 camshaft with black Parkerizing still showing around the lobes. There was no bevelling around the outside of the front cam.
When pulling out the HEI I found 1 of 2 wires came into contact with the rotating mechanical advance. I covered it with Goop glue and after it dries I'll roll some electrical tape around.
The HEI had an adjustable vacuum advance where the onion dome was pressed closest into the centre of the HEI. Leaving a long adjustment slot open. Alongside the adjustment slot is engraved "30".

#1) Could this be the cause of my highway overheating? An over advancing vacuum advance???
#2) The new cam is an Engle #18-20 approximately219-226 duration at .050. Will this be much different compared to the stock cam?

 

An over advancing vacuum advance would cause a lot of pinging under light throttle cruise. I would remove the pin in the connector and slip some heat shrink over the chafed wire.

That cam should be fine if your compression is better than 9. What are you using for an exhaust?

 

Stock cast iron X/Z manifolds and duals.
Compression is low............. the pistons are cast............. probably from some late model 455. The Chicago style deep dish Olympic sized piston centre holes are pretty big. -40 cc maybe more?
joepenoso

 

Talk to the manufacturer and tell them the spec's of your engine. A cam can be a benefit or your worst nightmare.

 

The lower rad hose is supposed to have a spring insert in it to prevent collapsing!