Hello everyone, I just stuck a valve in my 65 300. My question is am I better off sending them and the 4v manifold for full porting, polishing and bigger valves ready to reinstall @ $1900.00 or spend a little less and redo the stock valve train. This a 58K original engine w/ some mods: Headers, 625 cfm Demon carb, MSD 6a ignition etc. Thank you in advance for your trusted input. Rick
I just finished having that done to mine. I hope it pays off. Where would you be getting bigger valves BTW? I had to adapt valves from a couple other engines and have the guides sleeved for smaller stems... That cost a bit extra. It was about $1250 for the whole deal with a mild port and 3-angle valve job. IMO I think it's worth it but I spend way too much in search of a specific dream. There will be those who will say ditch the 300 (467lbs.) for a lighter/larger 350 (450lbs.). It's a strong argument. You'd probably spend more to do the swap though.
Thanks for your input. Like I say it's an orig 58k. car w/ factory air and power windows, buckets and console. I'm the second owner and would like to keep it a numbers matching weekend cruiser. I have spoken to Greg Gessler, [Gessler Head Porting] in New Jersey, He's excellent and that's all he does. This would be a full head port/polish- intake port/polish to match heads and all new oversize valves etc. w/ three angle valve job. I'm leaning that way while it's going to be apart anyway. Rick
You say the 350 is lighter than an aluminum head 300? Where's the weight savings? Is the 300 block a bunch beefier, or??
You'll learn a lot if you first port the heads, then have them flowed with and without an intake manifold. I recently dyno'd a 500 HP Ford 351C stroker engine. After some short side radius work, the heads alone flow 322 CFM at 0.600" lift. With a low rise Ford dual plane intake manifold bolted on, the best ports were in the 270 to 280 CFM range and the worst were in the 250 to 260 CFM range. To put that 60+ CFM drop in context, many cylinder head port jobs don't increase the CFM that much. The customer for this engine did not want to use a single plane intake because he wanted the engine to look externally stock so the Ford intake was ported in the plenum area to bring the 4 worst flowing ports up to near the CFM of the best ones. The resulting intake looked stock but was within 10 HP or so of a highly regarded single plane intake we tested (Holley Strip Dominator) and bested a high rise dual plane by quite a lot. Getting back to Buick data, I had a set of Buick 300 aluminum heads ported for my Rover/Buick aluminum V8 stroker project. Flow numbers are shown below, along flow numbers for an unported Buick 300 head with fresh valve job (probably flows a bit better than a stock 300 head). Valve Buick 300 Exh/Int Buick 300 Lift 1964 ratio 1964 (inch) aluminum (%) aluminum ported unported Int Exh Int Exh 1.775" 1.5" 1.625" 1.312" 0.100 66 47 71.2 0.150 99 82 82.8 0.200 129 104 80.6 105 96 0.250 155 119 76.8 0.300 174 130 74.7 135 108 0.350 187 139 74.3 0.400 191 146 76.4 142 115 0.450 194 150 77.3 0.500 196 152 77.6 149 115 0.550 200 153 76.5 0.600 200 153 76.5 154 116 Flow numbers were taken on a Superflow bench at 28" H2O with a clayed intake radius but no exhaust pipe. Larger valves and seats were installed, along with bronze guides. 6000 Series Ferrea Buick V6 Stage 1 valves were used. Intake valves are part number F6238 (1.775" head diameter, 11/32" stem, 4.735" long with a 0.271" tip). Exhausts are part number F6237 (1.5" head diameter, 11/32" stem, 4.735" long with a 0.254" tip). Intake head shape is a 10 degree Super Flo. Exhaust is a 29 degree tulip. Ferreas 6000 Series valves are competition parts suitable for solid roller cams. The larger valves required larger seats, p/n 30903 for the intake and p/n 30647 for the exhaust. The bowls were ported, along with the intake and exhaust ports. I'm pleased with the results. The stock Buick 300 heads flow about the same as a Ford 5.0L HO head (E7TE casting) and the ported heads flow about what an entry level aftermarket SBF head flows (Ford GT40, Edelbrock 5.0L, etc.). The exhaust to intake flow ratio is good and the low and mid-lift numbers are excellent. Pretty good for such a small valve head and should support my HP goals. My Buick heads are a "Stage III" port job which preserves adequate wall thickness for long life on the street. All out race port jobs will leave a much thinner margin between the ports (not good for gasket sealing but acceptable for a race engine that is frequently inspected and rebuilt) and will mill the chambers down. Your iron 300 heads may be different but in the aluminum heads, the Stage 1 Buick V6 valves are as large as you can go in these heads without offsetting the guides: http://www.bacomatic.org/gallery/album12/Buick_300_ported_standing_chambers_01 The tulip exhaust valve head helps the low and mid lift numbers quite a bit. Some close-up shots of the port work: http://www.bacomatic.org/gallery/album12/Buick_300_ported_intake_port_closeup http://www.bacomatic.org/gallery/album12/Buick_300_ported_exhaust_port_closeup http://www.bacomatic.org/gallery/album12/Buick_300_ported_chamber_closeup Dan Jones
Adam, No no. I meant his '65 300. They were all iron that year. Unless Rick swapped out the heads and intake. Did you? The '64 300 ≈ 400lbs. Nice post, Dan.
Nic, no the heads are stock cast iron and you are correct, the 64's were aluminium, 65's cast iron. Dan thanks for the great pictures. Rick
OK, I missed the 65 part somehow... I automatically think 300=aluminum heads though I know full-well they came iron headed too since I've had both.
OK- Here we go. Now I've been thinking about it and wondering if I should just get a new crate engine. As I said, this is an original 58k car Plus it has a new ST300 trans. that with the stock rear can't handle alot of power and torque. With a total of propbaly $5000.00 to rebuild the orig. 300 with the headporting and all am I better off with a new engine and if so do I need a Bo No: uick engine to match the trans? I'ts a tall order but I appreciate your opinions. Thank you Rick LiCastri
Yep, the trans has a BOP bolt pattern. If it's a money thing and you still have the 2-speed, why not just have your heads freshened at a local machine shop. A 58,000 mile motor has a lot of life left in it, or should anyway. You should be able to get new valves if necessary and machine work for well under $1,000. Just a thought.
Dan, I noticed the smooth combustion chambers, with no sign of a projection and was just wondering what the thought process was in grinding those out? Jim
Good question, Jim. I would assume polishing the chamber would be to keep the combustion temp higher? Is that what you were thinking, Dan?
I typically polish the chambers to help prevent pinging. However, the porter removed the bump in this case. He mentioned testing the swirl pattern by injecting paint into the airstream. He said the swirl filled the entire chamber, unlike most heads which localize in a particular spot. Not sure if the bump removal was related to swirl or not. Dan
I've been trying to remember what Phil Baker told me about the reason for that bump being there in the first place. It seem like it might have had something to do with the spark plugs but I really can't remember. Maybe somehow it aided ignition. Anyway, I've been trying to settle on valve selection. Although the 340 valves will go in, the balance seems less than ideal for a blower motor where I'm more concerned about getting the exhaust out, and if I want a bigger exhaust the intake cannot be increased so much. Dan, I see where you used a 1.625" exhaust and I noticed that this is the same size as the stock BBB exhaust valve. Stem might be a bit larger and I don't know if the length matches but the local parts store might have one I could look at. Those exhaust valves are too big to use with the 340 intake valves which measure about 1.820 (spec is 1.812") and it looks like the 1.750" valves are as big as you can possibly go. But the V6's use a 1.710 which might be just fine and leave a bit more room between the valves as well. In fact, I'm thinking I may be able to cut down the 340 valves to that size and only have to buy new intakes. Anybody know of a reason that wouldn't work? I should be able to trim them on the lathe and let the shop finish them. I know that doesn't seem like a lot of difference between the size of the intakes and the exhaust, but it still means the intakes are 0.080" bigger than the stock 300 valves and with the blower I'm thinking this may be enough. If I just cut them down to 1.730" it'd be 0.100" bigger and only .082" smaller than the stock 340 intakes. I could also consider using the 1.550" valves from the 350 if it made sense to do that, which would leave another .075" for the intake if I wanted it, or I could use the stock 340 intake and a 1.500 exhaust. Seems like I have too many options. Anybody care to make a suggestion? THX Jim
It's a bit confusing how the numbers are listed in that post by Dan but I'm pretty sure the reference to 1.625" valves was for the stock 300 intake valve. I like the idea of the 1.55" valve... Anybody know how long a 350 valve is? Is it longer than 4.735" (The length from Dan's article)? Were the 340 valves longer than the 300 valves? I like where you are going with cutting down the valves from the 340 to fit. What would be the drawback? That could be a good solution for bigger valves in a 300 head then. What are stock 340 valve dia.? Is it 1.812" for the intake? Do you still have the stock valves in the 300 heads now? What about just focusing on increasing the exhaust side...? Just to solidly confuse things. That post by IgnitionMan on BuickThunder mentioned he's using later Corvair valves at 1.5" exhaust. Might be something to look into.
I think the 300 and 340 iron heads used the exact same valve. In fact, they are probably the exact same head I'd guess, meaning that all Buick did was increase the stroke and deck height and maybe used a different piston pin height in going from the 300 to the 340. I don't know yet if the valve length of the 340 is the same as the 215 but as soon as the weather warms a bit I'll find out. As previously noted there are big differences between the alloy 300 and iron head in the port and valve sizes but that may be the only significant thing changed up until they changed to pushrod oiling. (which my engine does not have) It's also worth noting that the intake valve size on the 215 is 1.500", which raises another possibility. I rather doubt there's any difference in the alloys used in the valves for intake and those for exhaust in the early 60's. Does anybody know of a reason why you couldn't use the 215 intake as an exhaust in the 300 head? It would be an increase of almost .200" which should be pretty significant (1/8" larger than stock 340), and at 10-15 bucks each that's around a hundred bucks that could help pay for the new seats. It's also interesting that the 215 has marginally larger exhaust valves than the '64 300. http://www.taperformance.com/PAGES%20PDF/2006F_1.pdf page 64. So what I'm possibly looking at right now is a 1.5" exhaust and a cut down 1.75" (or so) intake. I don't know that these sizes would be the best I could use, but they will be better than the head came with, and I have the valves on hand so I only have to pay for the seat work. Which brings up another question. I do not understand how the seat inserts can be installed so close to each other in the case of these max oversize valves. Are they cut to the same OD as the valve? This would mean there is very little material left between the two inserts, if any. Cast being somewhat brittle I can hardly imagine being able to make those cuts without breaking through to the other pocket unless there was a minimum of about .030" left between them. Is there something going on here that I don't know about? Jim Edit: The 1.5" valves just touch the 1.820" intakes installed in the 300 head so at the least the intakes would have to be cut down a bit to work. How much, probably determined by the available seats. The length of the 215 valve is slightly shorter than the stock 340 exhaust, something around .050" so close enough to work I would imagine.
> Dan, I see where you used a 1.625" exhaust and I noticed that this is the > same size as the stock BBB exhaust valve. That's the intake valve size of the 1964 300 head. The forum software removes multiple spaces so doesn't preserve formatting but I posted numbers for ported and stock heads. My ported heads use 1.775" intake and 1.5" exhaust. > I should be able to trim them on the lathe and let the shop finish them. Remember the tips are heat treated. I trimmed a set of Ford Y-block valves and had them cut for new keepers for a set of home ported Buick 215 heads. We had to re-heat treat the tips. > I rather doubt there's any difference in the alloys used in the valves > for intake and those for exhaust in the early 60's. Not true. I don't have my reference for the 215 here but I do for the Buick 300 and they used 21-4N for the exhaust valves while intakes could be SAE 1041 or 1047 or TS-8150 steel. 21-4N is an austenitic stainless steel similar to 21-2N, except for a greater nickel content (4%) and is used as a heavy duty alternate to 21-2N. Dan Jones
