Re: 1971 Buick 455 GS F/SA G/SA Build
 

Nice car and great to see some Buicks out there. I remember this car when it was for sale a few years ago. Good luck and post up some pics.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I have the complete engine torn down, block and crank cleaned. What I've learned: the 661 heads flow about the same as the 149 castings which is good because they seem to be very hard to come by, I have bearing clearance issues to deal with on the mains, the cam tunnel has been opened up on the high side of the spec, hopefully a coated bearing will help there. Rods are stock Buick with Venolia pistons, some deck heights to deal with, seems I have something I can work with here.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

At this point I have the intake side of my head where I want it, its time to look at the exhaust side. Intake valve size is 2.005 on 315/330 HP 455. Valve job is 30/45/60 30 degree back cut on the valve.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Really? 30/45/60 30degree back cut.....so a normal 3 angle cut? Did you flow the different angles and the 45 seat with 30/60 on either side flowed the best? That's interesting and certainly not what I was expecting. Having never seen the chamber I'll assume from that, that the chamber is big enough to not shroud the valve. (or the valve is small enough to not need the help)?

How wide did you make the seat?

From what others experienced with Pontiac's mimicking sbf flow characteristics, I thought the buick would follow suit. Apparently not!

Excellent, keep it going, let's see what the exh needs!

Re: 1971 Buick 455 GS F/SA G/SA Build
 

goingbroke you have a PM

Thanks
Rick Thomason
GTOMayhem

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I wouldn't say my angles are optimum, but I was happy with my gains from the previous setup. The 45 was .040 wide. Its important to note the engine as run as tested (474 HP) in this thread had flow numbers @ 28" of

.200 131.9
.300 185
.400 211.7

Which leads me to this: 176 CFM @ 28" through the intake manifold @ .400 lift, which makes me wonder if there is lofting of the valve involved as mentioned by a friend?

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Here you go.....

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Looks awesome! Cant wait to hear how it runs. Good luck

Re: 1971 Buick 455 GS F/SA G/SA Build
 

My head development is done, some gains were made. Working on the short block now, it seems the piston/rod combination is "only" 239 grams over the minimum so something will have to be done. The ring pack will be updated as well. Deck height will also have to be looked at. I very much look forward to getting this engine back on the dyno!

Re: 1971 Buick 455 GS F/SA G/SA Build
 

How is the hard work coming along.? Nice build and some more pics would be great.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I was able to get my short block back together, she a rough old girl. 3.912 stroke with a 4.342 bore, 10.69 compression. After finalizing my head design I started on the valve guides, I also ordered some seats if they are needed.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I proceeded with the valve job, and of course after setting my valve depths there was one problem child, a seat that would not come in at the proper height after replacing all the guides, good thing I had seats made to fix this potential problem. I installed a intake seat, problem fixed. Valve job is done, CCs will be set at 59.5.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Nice work, as always. Those Buicks are cool. :) -Al

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Looks great to me! I play with Olds and tried the trick valve seat angles and now back to 45. I think with aggressive dwell square cams it leads to uncontrollable high gear problems, I even tried 250 on the seat. Also going back to cast iron guides, have learned bronze has different expansion rates and will tighten down. Good luck!

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Are they the thin wall guides you were using.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Solid bronze will seize up. I had it happen on my tow vehicle. Exhaust valve got hot pulling a hill and valve started to seize and bent hitting piston. Screw-in bronzewalls or thin wall types never a problem like that. They are softer and more self lubricating. They do wear more easily though. Cast iron guides also can easily seize. I honed thinwalls and screw-ins until the valve would spin free and never had one seize. Nice pictures and work on those heads. Makes me want to go back and do that work as I did for years.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Solid is for alum heads only - never knew. Liners are ok

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Sold bronze will work in iron heads but they need a little more clearance on the exhaust side.
I have seen many places not use seals also to let a little more oil in there on that side.

After I thought about it the guide that seized on my tow vehicle was a screw-in bronze.....Only one to ever do that in my memory...

I like the thin walls the best....honed to fit with a Sunnen hand hone....

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Thanks for the nice comments. Lets talk about valve guides and valve jobs. These particular heads utilize bronze knock in guides, the guides are bought with the ID .370 (undersize) the guides are installed which distorts the ID, I then cut a carbon relief slot in the bottom of the exhaust guide with a .450 reamer .125 deep. I use carbide core drills (similiar to a K Line core drill) which I had made, the guide is drilled to .3715 making it strait and round, the guide is then honed to final size with a Sunnen hone with Sunnen hone oil. You now have a perfectly round and strait guide, which allows you to cut a perfect seat. A perfect contact patch on the seat allows you to transfer the heat in the valve to the valve seat.

Rich.....I know you like this stuff, ck out this link

http://www.chevelles.com/forums/13-p...-pictures.html

Look closely at the valve contact patch (lap lines)

Re: 1971 Buick 455 GS F/SA G/SA Build
 

" I then cut a carbon relief slot in the bottom of the exhaust guide with a .450 reamer .125 deep."

You lost me on the above operation ? A picture is worth a thousand words.

Practically all the head work I did over many years was without the use of a seat and guide machine. Benchtop operations.....hand held drills and tooling.

I did buy out a machine shop in the early 1990's and that buy included a Kwik Way 019 S&G machine. I did not use it much. Eventually sold it for a giveaway price.

Nice work on the BB heads and I hated replacing the stock guides in them. I would leave them and thin wall line them mostly due to the rediculous way GM factory drilled the guides off center from the seats on some. Also the potential water leak issue passing thru the water jacket.

I have taken brand new aluminum heads from the big name manufacturers with nice looking Serdi cut seats so far off the old valve bounce test is a NO bounce and just a thud......LOL

Bought a set of Darts for my own engine. Operator who did the VJ on them must have been drunk......had to use my old school stones to fix it.....Not fun but I make it work...

Your work is excellent.....

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I finally got the exhaust side of my heads done. Although I'am not sure I have this right, so I have questions. On my BBC builds with conventional camshafts I've always wanted lazy low lift flow then have it come on after .300 lift and take off, this has always worked well for me. On my Buick I gained around 12 CFM @ .200 and 12 CFM @ .300 and about 10 CFM @ .400 and finally 9 CFM @ .466 peak lift, will this help me or hurt me?

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I almost didn't answer this because there's not enough info to make a valid response ( again, where are the .100 flow figure improvements on intake & exhaust). Also, i don't know what was done to improve the intake or exhaust flow. You are definitely going to have a (seemingly) wilder cam with low lift flow increase. You will have more reversion, true, but, in my opinion, you are going to see a substantial performance increase. Ron.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Ron, I will send you the flow numbers in .050 increments, I'm actually scared to to see the increase @ .100 lift on the exhaust. Intake to exhaust flow is roughly 67% @ peak lift.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Sorry for delay, Mark. As Mike Taylor, Adger Smith, and others have said total and/or average flow is more important than peak lift flow increase at the expense of lower lift flow. I did not see anything exorbitant in your low lift exhaust numbers. Frankly, there is probably more potential low lift available. There are, of course, ways around the reversion issue if that is what concerns you, but I don't think you will need it. In short, yes, IMO, it will help you. Ron.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Heads are finally installed on the engine. I would not look forward to doing another set like this :eek: Now I've got to fit the intake which I could see taking a day to get a good fit, then its dyno time.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

My preliminary dyno results are in, peak HP so far is 513 HP/550TQ. I will be making some changes looking for more, I will post up the results when I get done. More work and more HP 522 now.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I finally finished the engine part of my F/SA build. I want to say thanks to the following people for their help.

Harold Bettes
Jim Lewis
John Lewis
Chris Skaling

Dyno test from before the engine had been gone through is on the first page of this thread, dyno test of the finished product below.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Have you tried any header tuning while on the dyno? These engines really benefit from the exhaust scavenging. That is why the original Stage 2 heads were so effective.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Congrats on your hard work paying off. Nice power. Small valve low compression engine. I look forward to hearing about testing now.
Chris

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I tried different lengths of extensions, the best were in the pictures. Merge collectors were not tested.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Thanks, I have tested Aug 19. In F/SA trim I ran 11.40 with zero tuning at Pueblo Colorado 4800 feet elevation, 25.10 baro, 7240 DA, .9508 correction, running the Turbo 400 with 4.10 gears. My next change is testing different carbs, a metric trans and 4.30 gears along with a rear end redesign. I really wish I had the time to really get after this combination I think it could really run.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

You ran 11.40 actual et? What is the index at that altitude then?
Call me..Can't find your number ..Have an unrelated question for you.
602-769-0346

Re: 1971 Buick 455 GS F/SA G/SA Build
 

The index at Denver for F is 12:60 would have been #1 qualifier at the last national with that run.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

The F/SA index for Pueblo should be around 12.46 a run of 1.06 under at altitude is very impressive!

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Pueblo is about 1000 feet lower than Bandimere, but I'am sure I can run 11.60s there.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Great news
I know finding time is key
Same here working on my velle and GS too.
Better get outside now.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I don't know the index in F for Pueblo, although the NHRA correction is .9508. 11.4 X .9508 = 10.84 not earth shattering.....but I'am just getting started. Stay tuned.

Re: 1971 Buick 455 GS F/SA G/SA Build
 

11.40 / .9508 = 11.99

Re: 1971 Buick 455 GS F/SA G/SA Build
 

Dwight,

Hunter was taking his run back to sea level with the .9508 factor. That's what that factor does. You divided instead of multiplying. As an example, the factored Index for Pueblo, 12.46 x .9508 gives you the sea level Index of 11.85.

Lots of people who aren't "altitude runners" get these factors all confused.

Jerry

Re: 1971 Buick 455 GS F/SA G/SA Build
 

I thought the index was 11.40 and was translating to the altitude factor. If the uncorrected index is 11.85, then the altitude factor is 11.85 / .9508 = 12.46