Tall vs short valve covers

[Guest 007fastZ]

What is the difference b/t tall and short style valve covers, besides the height. I'm running a mechanical flat tappet cam, with roller rockers, i wouldnt think i need tall valve covers, what is the advantage

[Guest Ground Rat]

The only advantage I know of is being able to fit a taller valvetrain underneath.

[grumpyvette]

most guys with corvettes stay with the stock valve covers unless forced into swapping , due to clearance issues caused by the use of roller rockers, stud girdles or other aftermarket valve train accessories. On some corvettes theres serious clearance issues with the windshield wiper motor housing and valve cover or accessory brackets that make using tall valve covers difficult

 

but one thing that has not yet been pointed out is that the taller valve covers do have some slight advantage other that just additional clearance on the rocker assembly, and that slight advantage is they have increased surface area thats exposed to the realatively cool air of the engine compartment,compared to the oil temp, altho the air temp in the engine compartment may reach 170-190 degs its still much cooler than the oil that can reach 230-280 degrees while racing, that allows the constant sheets of oil thrown from the rocker assembly onto the inner surface to cool as it has the heat absorbed as the oil runs over the inner surface on its return to the sump. in effect the taller valve covers greater surface area acts like an oil cooler that helps cool the valve springs very slightly. now it may only be a few degrees but each little advantage adds to the effiency of the total lubracation system.

I try to use those tall cast aluminum valve covers just for that reason even if they are not mandatory. another advantage is that the oil seperator baffles tend to be possitioned further from the flowing oil in the cylinder heads making it less likely that the breathers allow oil film to blow onto the outer engine or the PVC valve to suck oil into the intake on older engines with worn rings

 

BTW ,if they are sbc perimeter valve covers

JEGS sells these that help a great deal

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=2207&prmenbr=361

a few things you should know

 

[1] synthetic oil desolves that yellow 3m weatherstrip gasket adhesive than many guys use over a few months time so you can,t use it to glue valve cover gaskets (IT WAS NEVER INTENDED TO BE USED THAT WAY ANYWAY, WEATHER STRIP ADHEASIVE is NOT TOTALLY OIL RESISTANT, you should use the correct adheasive

 

[2]you must use a o2 safe gasket cement like the BLACK RTV silicone cement and you must clean and degrease the cover with acetone or a similar solvent before glueing on the gasket to get the best retention

 

[3]you need to allow at least a few hours to over night,depends mostly on temp. for that black silicone gasket cement to set up before installing the valve covers, and placeing them gasket side down on a table with a sheet of wax paper under them and a 20lb weight on top of each valve cover while the cement sets up is the best way to insure the gaskets stay correctly aligned on the valve covers perimeter

 

[4]a light coat of (PAM) cooking spray on the lower gasket surface keeps them from sticking to the cylinder heads after installation

 

[5] these gasket retaining rings add a great deal to the valve covers ability to firmly hold the gasket WITHOUT bending SHEET METAL VALVE COVERS OR CRACKING CAST ALUMINUM VALVE COVERS AND ARE WELL WORTH THE MINIMAL COST

 

[6]tall valve covers allow the use of stud girdles that if correctly installed with matching poly locks on the rocker studs aid the valve train stability and can allow gains of several hundered RPM before valve control problems occure

 

[7]doing it correctly the first time saves time and money

[Guest zfan]

As usual very good information! Thanks for the info even thou I did not ask.

 

Mike

[Guest 007fastZ]

Thanks alot for all the information, that is well beyond what i expected.

Is there any clearance issues with a 280zx 350 small block swap with tall valve covers?

Once again thanks again

[cameron]

u get a lot more oil slop with tall valve covers that dont lub the insides as well

[danc]

Since you are talking about valve covers, I had a problem with the Aluminum Bowtie Valve covers (you show) sealing properly. Tired several different gaskets; including Profrom, and they still leaked. Ended up talking to the guys at Sallee Chevrolet since they sell a ZZ430 clone (which is what I have) and found out they use Felpro Part# 1608 which is a thicker gasket. Sealed no problems...