When gasket matching the intake,you want the intake manifold port to be ever so slightly smaller(1/32 should be good) than the intake head port so you won't have any air reversion if there is a slight mismatch when it bolts together. The oppisite goes if you're going with ported exuast manifolds,you want the manifold port to be a little bit bigger than the head exuast port. So far,it looks like its going to be a good runner.:TU: Derek
The question with hardened seats is will they blend them into your porting as they are sized for 1.500 valves and your installing 1.550 .kinda kills the point of big valves if they don't. Not to start a war on seat replacement but most iron heads don't have them installed originally even in newer cars .and Gary mentioned poor tune on his.so its all depends of machine shop and condition of head. I haven't had any problems with TA with parts I have gotten with them but if you have questions have them ready before you order as sometimes they will have to get a tech to answer.
Just thought of one more thing, blocking the exhuast crossover in the heads, i know people use freeze plugs can someone point me in the direction of some i should order? and i need a total of 8? or is this something i shouldnt do? Im in southern california so the weather isnt to cold most of the year.
Gary,hardened seats won't protect stock valves from "burn out",hardened seats are so the valve seat doesn't get hammered on which will cause the exaust valves to sink in the head,and spring pressures to go down because the installed height will now be taller. Sustained high rpm and eccessive exuast gas temps,with weak stock valve springs probably caused your valves to "burn out",not to mention lesser expensive production valves that were probably abused at least one to many times. o No: Did you remove the heads back in the day when this happened? That would of told the real story?:Brow: I'd say if TA recommends(or doesn't) hardened exaust valve seats,they would know if they're nesasary or not. :beer Derek
That's part of it too, Derek, but the hardened seats will also help protect the higher temps from 'welding' the valve to the seat then breaking back apart, leaving pits and irregularities around the seat, causing blowby and the 'burnout' for lack of a better term. The intake would be just as susceptible to this hammering effect with weaker springs as the exhaust in this regard, though the only real threat to getting hammered, whether it be intake or exhaust, would be valve float. I'd say the biggest concern would be the excessive exhaust gas temperatures with said sustained high RPMs or excessive abuse, so while hardened seats might not be absolutely necessary, they're good insurance. :beers2: ---------- Post added at 12:44 AM ---------- Previous post was at 12:41 AM ---------- I was going to say this earlier, but got sidetracked and forgot. Thanks for bringing this up, Derek. ---------- Post added at 12:47 AM ---------- Previous post was at 12:44 AM ---------- I would have them install the seats then get the heads back and blend them in myself, then send them back for valve job and assembly. I dunno. I figured the seats were extra insurance against burnout, but if you guys think everything would be fine without them, I'm not resistant to accepting new information. Also, TA installs hardened exhaust seats in their Stage 1 iron heads they sell for 350's by default, so I figured they knew what they were doing.
ill make sure to ask what TA says about the hardened seats when i order tomorrow im not complaining if they say they arent a must it will save me about $120. Ive been looking at alot of other posts on Google about hardened seats and the majority seem to think you don't really need hardened seats. Mostly Chevy forums but what do Chevy people know:3gears: Thinking about that thought if they don't think you need it and the Buick heads are stronger material wise then the Chevy... idk that might be dangerous thinking.
It's just extra insurance. You may not even need them as the others and I have suggested. The Chevy guys are probably talking about heads that are later year models so the heads will probably have been improved. If I'm not mistaken, I seem to recall the 'hardening' process is actually done to the head itself around the seat, and that doing any kind of valve job removes the hardened iron so that either a re-hardening will be required or steel seats installed. This is why no heads came from the factory with hardened steel exhaust seats...the seat was already hardened (but the rest of the head was not). Buicks I don't think suffer from this as the entire head is 'hardened' with the extra nickel. Mind you, I'm not an authority on this subject, I'm just relaying the information that I have to you. If I'm wrong, that's cool, I want to be corrected. I would hate to pass along shoddy info to someone. Back when they used to put lead in the gasoline, this wasn't an issue. The reason is that lead is inert so it doesn't burn, but does form a coating on the combustion chamber. This coating served as a 'dry lubricant' for the valves, preventing the 'welding' effect I mentioned earlier. Once lead was removed, the older engines running on unleaded suffered from valve burnout. Buick foresaw this issue ahead of time and made their iron better.
Additional info on this subject came up arbitrarily in another thread I was involved with. Here's a quote from Jim Weise: "It's widely known in the industry that Buick used a higher nickle content iron than other makers. This is nothing new, and is not an oil wives tale. For the foundry men at Buick, it had nothing to do with strength.. the addition of about 4% of Nickle simply made better castings, and this was critical to successfully achieve the engineering goals for the 400/430 engine project. Those goals being a lightweight, large displacement engine. Thin wall castings were critical to this design, and they needed the reduced shrinkage and lack of other casting defects that the inclusion of the nickle allowed. A nice side effect is that iron head valve seats were more durable, the cast iron is somewhat stronger. It's certainly not ductile iron, but it is better than plain Grey iron. To my knowledge, I do believe all GM divisions when to the induction hardening of the exhaust seats in the castings in the early 70's. Interestingly enough, the only 400/430/455 heads I have ever seen with exhaust valve recession, were real early 400/430 ones (one head) and then the 75-6 head (fairly common) The last incarnations of the big Buick motor were so detuned(reduced compression and lower ignition timing, leaner carburetor calibrations), they ran hot all the time, so that has always been what I attributed the later heads issues to. The 67 head was an anomaly. In fact, due to the thin wall castings, machining Buick heads for seats inserts is always a crap-shoot. The water passages are right there, waiting to ruin your day. I personally have built and used several 455's in high stress towing situations, and even with a steady diet of regular unleaded, have never had any issues with exhaust valve recession. The latest version is apart on the stand now, as it slit a radiator hose, and leaked all the coolant out, causing a traumatic overheat situation. Those heads that had a fresh valve job, moderate spring pressures and were used in a towing vehicle, look pretty much brand new after almost 30K miles. I always advise folks to not put hardened seats in Buick iron heads, you have a much greater chance of running into water leakage problems with those seats, than you would of having valve recession issues. As far as fuel requirements, 91-93 octane Premium unleaded, with no ethanol additive, is your best bet. Ethanol is no real problem in a completely rebuilt vehicle, with a new clean gas tank, and alky-resistant rubber hose, but it can cause issues in untouched cars. JW" So on big blocks, he says 'not advised'. So I guess some say yes while others say no. In light of this, I think I would just save the extra money and not bother with hardened exhaust seats. More good news! G Edit: Another thing I was thinking about is the use of the stainless steel swirl polished valves. I would say that this would increase your odds of success even further since the valves are stainless steel and harder/more durable than standard OEM replacement valves. This would effectively serve a similar purpose that the hardened exhaust seats would, only instead of in the head, it's the valve itself that's resistant to welding. So double thumbs up on the 'no hardened steel exhaust seats'.
Don't forget to check out the 'edit' on my last message. I think you'll be good to go without them, especially with the use of those stainless steel valves. ---------- Post added at 01:10 PM ---------- Previous post was at 11:57 AM ---------- Here's more information on the subject to check out. I believe it to be relevant and very interesting what others have to say about the hardened seats. http://www.v8buick.com/showthread.php?272748-Fuel-Requirements&p=2242779&posted=1#post2242779 Seems the heads will be fine as long as there haven't been excessive valve jobs done to the heads, otherwise, hardened seats. Much of this has to do with personal experience that others have had, and so may vary depending on circumstances. Their issues weren't so much about valve to seat welding as it was seat recession as Derek was talking about earlier in this thread. I would think faster ramp profiles and stiffer spring pressures would play more of a decisive factor in whether or not to use hardened seats.
o No: but even if i could i think the 10-12 hours of grinding i did on these heads are worth more then the $120 i would spend on new seats..
Called TA this morning and placed my first order with them, i bought the complete valve set, stage 1 springs and 2 cans of Buick red paint.. The total was around $336 (forgot the actual numbers) and should be here by the end of the week i think.. By then (hopefully) ill have the money together for the rest of the head work and i can take everything to the machine shop! Woo Hoo!
Well the package came in today I can finally get rid of the black block and get it lookin good. Now on the springs the sheet of paper says if i want to keep the inner springs i have to do extra machining which i dont want to have to do anything extra that i dont have to do for cost sake. Is this something i can avoid? or something i should really do.
Sweet! The 'inner springs' are the dampers (some call them dampeners) which do what they describe: dampen vibration and reverberation at varying RPMs. Whether you need them or not I can't say. If it were me, I'd do the extra machine work to put them on, but I suppose if it were imperative they be installed, TA would have said something about that. Stock Buick 350's came with and without the dampers, and some only came with dampers on the exhaust side, depending on need. Using the dampers will create extra heat on the valvetrain from friction (though I doubt this is enough to make it detrimental to anything), just something to note. So this is something I'd like to know too, if someone else here has any input on it. Otherwise, you can always call TA and ask.
The sheet basicly says if you dont want the hassle of machining to take them out so they dont seem that important and any more machine work means more $$$.. Ill wait for someone else to chime in.. In other news my block now looks like it should!
Ok my 2 Pennies... I think the dampers are supposed to be removed during cam break in. What is the purpose of buying the stage? Springs if your not going to use them as directed? Can anyone comment on this???
