Aircooled Volkswagen Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
92 Posts
Discussion Starter · #1 ·
I finally got the rocker geometry set up on my 2276, an was going to reassemble the springs, retainers and keepers. Just by chance I looked at the exhaust guide, and noticed the guide boss has a crack!! These heads came from a reputable head porter, and after talking to him he said not to worry. I believe in second opinions though. Is this a common problem with the 044 casting? Is it really no big deal? This is my first set of real performance heads, and want your opinion. Thanks DS
 

·
Premium Member
Joined
·
634 Posts
generally speaking exhaust guides have substantial support and a cracked boss will be cause for concern only in cases where super high lift and spring pressures are involved. The same can't be said of intakes however, most commonly used heads have minimal intake guide support as sold.

D P
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #7 ·
Don What do you consider high lift? I'm running a web 86b cam and a set of Berg 1.45 ratio rockers. My lift at the valve is in the neighborhood of .592". Will I be safe???
 

·
Registered
Joined
·
1,179 Posts
I will chime in a bit on this. There has been a trend to get BIG lift on small duration cams lately. The lifter to cam may not be a big deal but the rate the valve is accelerating is a big consideration. .600 lift on that cam (260 dur @ .050) is overkill IMO. Lot of problem will be to get a spring that will control that amount but not kill it. Another .050 in lift maybe a few hp but depending on spring rate another .050 maybe enough to kill the cam or take away from seat psi (in order to control nose psi) and hurt valve control.

On a K-800 spring (most common chevy) and a long valve (like cb racemaster) you can get away with more radical valve action compared to a common vw diameter dual spring etc. I am guessing you have vw diameter springs as this is a 044 casting. Another issue will be controlling that lift with a stainless or heavier valve. 42-44mm diameter valve will need a great vw spring on that head at that lift.

Just my opinion on what I have had issues with before.
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #9 ·
Thanks for the reply Jeff. When I had the heads made I gave the cam choice to the head porter. I trust that he knows what he's doing as he is a reputable head porter/builder. Yes I believe that the valve springs are VW diameter, and hope that he has set me up with quality springs to handle the job. Otherwise I guess I'll have to upgrade when they go away!!!! They are 42X37.5 stainless valves BTW.
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #11 ·
The car will be used as a weekend warrior, with a road trip trown in just to be intresting. I'm hoping that it won't be too much for these heads!! Especially since I've found what I have!!
 

·
Premium Member
Joined
·
634 Posts
I'd have to agree with Jeff about your lift / duration numbers, while I don't feel the cracked boss is much of a concern I'm not at all wild about a near .600" lift with that kind of .050" figure... and topped off with springs that are all done at .500" under ideal conditions.
you are on a path to destruction, re-think your combo to something a bit less agressive either cam or rocker ratio and get hard numbers on spring pressures, it is unwise to be in the dark about such an important variable.
D P
 

·
Registered
Joined
·
3 Posts
High guys my name is Bruce not the Bruce that worked for mofoco lol I'm not trying to cut in or be disrespectful ...but I had recently got my self a sand rail with dual Webber 40 043A heads 91.94 pistons tri mill exhaust dual relief case light weight timing pully pentronix ignition no vacuum advance chromoly pushrods separate oil cooler I don't know how to tell what rockers I have or cam ....but my valve guide came loose on the exhaust for cylinder number 3 could someone please help me figure out what I have and what I need to get so I'm not just putting a bomb together lol thank you all comments good bad and the ugly appreciated
 

·
Registered
Joined
·
3 Posts
High guys my name is Bruce not the Bruce that worked for mofoco lol I'm not trying to cut in or be disrespectful ...but I had recently got my self a sand rail with dual Webber 40 043A heads 91.94 pistons tri mill exhaust dual relief case light weight timing pully pentronix ignition no vacuum advance chromoly pushrods separate oil cooler I don't know how to tell what rockers I have or cam ....but my valve guide came loose on the exhaust for cylinder number 3 could someone please help me figure out what I have and what I need to get so I'm not just putting a bomb together lol thank you all comments good bad and the ugly appreciated
 
1 - 14 of 14 Posts
Top