got some 430 heads for my project...on one head, the casting where the valve guide goes into is "busted off", so it just looks like half of the valve stem is sticking out of the head with no casting around it. The big umbrella seals wont go on em, but since i have dual springs, i need to cut reliefs in that casting part anyways right, and i'd need those smaller seals anyways. My big question is there any chance any oil will leak because of the casting being missing? I have done a lil bit of inquiring and was told it was fine, but i wanted to see what some experts have to say. I wanna get a good answer before i start pumpin money into these, thanks!! -also how would the smaller seals fit on? right on the valve stem?
If you've got a good shop they may be able to help. Bornze guides (not bronze liners) can be had with some pretty beefy OD's. You may be able to locate a set that would let you use the 1/2" ID teflon valve seals, then you don't have to rely on the damaged casting at all. Devon
Hi, I tried searching various threads for an explanation of why it is useful to use 430 heads on a 455. No doubt this question has been asked and answered many times, but did not find anything. Higher compression? Do the iron 430's with big ports flow better than ported iron 455's? thx
There are a few casting numbers for the 400/430 that reflect a "big port" design. They're really not that much different visually from any other big block head. If you're already planning to have professional port work done, any big block head is fair game...the exception is the late open chamber heads which have no port problems, just larger combustion chambers thus lowering compression ratios. One drawback to the '67-'69 heads is weakness in the valve spring seat area...they are prone to developing cracks with higher than stock spring pressures. I've had to repair mine more than once and am quite tired of it! Let me see if I can dig up an old article about the big port heads... Devon
http://home.comcast.net/~shinzan/part1.gif http://home.comcast.net/~shinzan/part1-2.gif http://home.comcast.net/~shinzan/part2.gif http://home.comcast.net/~shinzan/part2-2.gif Devon
Thank you! Very interesting articles. Where can one find copies of the magazine - there were other very interesting articles advertised. Greg Gessler, Cylinder Heads III, etc.
Honestly I'm not sure. They were posted by another board member a couple of years ago, I just saved them for future reference. Maybe one of the Buick club's newsletters? Devon
You want a guide like this to replace your broken valve guide boss: http://www.gesslerheadporting.com/members/gesslerheadporting/ghp.nsf/822dcaaaa26c6da985256dd80023623d/eaee641ec983ec0985257112007d1967!OpenDocument They accept a good positive seal and also sized to accept valve spring locators.
im not 100% if u guys r sure what im talking about...I guess years ago, someone dropped something heavy on it, and it split off a couple castings around the guides. i want to install new stock guides into the 430 head, but the circular casting that goes from the head to the top of the guide has broken off...cracking 430 heads arent the issue...but rather if i can still use the head by putting in new guides and calling it a day.
Maybe you can post a picture to help. You can't install "stock guides". The original valve guides are part of the casting itself. The repair Greg and I have mentioned require boring the entire guide out, and installing the bronze cylinder. These large tyes of guides completely replace the cast protrusion that holds the valve stem seal. All of the damaged area you mention is machined away for the replacement. Once in place, instead of the cast iron valve guide sticking up, you'd see the bronze instead. Any competent shop should be able to handle this...if your shop guy is scratching his head, time for another shop! :grin: Devon
thanks dev i see what u mean...however, the 430 head im speakin of already has brass guides portruding out of the casting...? but maybe i'll just have to bite the bullet and get some special guides also, about the "weak" spring seats in those heads...ive never heard about that until now...im putting in dual springs and i have .060" shims that i may/may not put in aswell...is that a problem? All ive heard is good things about putting duals on those heads
I run dual springs with around 135 psi on the seats closed, around 315 open if I remember right. With that, I've had to repair the cracks twice. Not that there were any symptoms mind you, but they just made me nervous. Devon
The VERY informative article seems to suggest that all 400/430 heads from 1967 are "Big Port" but in the summary for 1967 Heads he mentions casting #'s from 1967 that he did not verify. Did Buick have two different head designs in 1967 for the 400/430 engines, or will any 400/430 cylinder head from 1967 be Big Port?
There are a few in '67 and '68 that reportedly don't fit the "big port" category...see the info on these pages: http://www.gesslerheadporting.com/m...8464cf4d587de6d085256e47001720b1!OpenDocument http://www.buicks.net/shop/reference/bigblock_casting_numbers.html Devon
Thanks! Can anyone verify the casting number 1382986? Buicks.net indicates that this is 1967 Big Port, but Gessler does not indicate Big Port. Cross check of all the other numbers shows agreement.
