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65wildcatconvt

safe redline for 401 nailhead with 115k miles

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A power steering pump rear bracket/brace can be possible (although I don't know specifically what's on the particular model of Buick you have). Might have been a particular thing they were trying to minimize or keep from happening?

NTX5467

My 64 Riviera has the same brace and it is a substantial piece of steel, probably 3/8' thick. I figured it was for keeping the engine from twisting as it is not needed for the power steering pump. That is held on by a couple of studs off the head bolts.

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4400 to 4600 was the factory shift points for stock 401's around 1965. Gran sport Riv's in 65 raised to 5000.

Your best bet is good plugs, wire, points and proper working carb. Bump the timing ( also an advance kit in

the distributor), make sure the switch pitch switch is working, leave it in drive and go for it!

Good Luck

Bill

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thanks all- i am borrowing a camera from my girlfriend this weekend and my #1 goal is to get some pics and get them posted next week if possible so you guys will see the car is for real.

found a sun tach in a box from 1982 so going to discreetly mount it in the car somewhere and set the redline needle on 4 grand.

thought i heard somewhere the th400 modulater is adjusable with a screwdriver... as in possible to firm up the shifts a little, has anyone ever heard of that? its a tad mushy for me, i put a shift kit in a th400 back in 82 not sure if i want to go that route...

my car is basically a "20 footer" or like number 3 condition but i am super blessed to have it and really enjoy trying to preserve it and prolong its lifespan, but it will never be a show type car so i think a few small performance mods would not detract from it. goal is to always have it driveable in the summer months so i still have 3 months to get her ready ha ha.

The adjustable modulator will alter the shift timing because it only alters the vacuum signal message. The nice thing about a shift kit ( B&M) besides only taking a 1/2 hr. to install is that when the shift lever is in drive, the shifts are just like a stock T-400, it only shifts firm when you are manually controlling the trans.

FYI, all of the GM family when each division had it's own engine with the exception of Chevrolet were designed for torque. The Buick nail head is no different. The stock camshafts and small valves and most importantly it's restricted exhaust passage configuration hold it to 5,00 rpm or less. With a factory cam with the trans in gear under load you would most likely float the valves in a good conditioned engine before it would blow up. You need to remember the Buick nail head is a compromise in the original concept for the engine, that engine was too expensive to build. That engine (1951) 216 cu. in. V-8, aluminum block and heads ( heads were hemi chambers ) made 335 HP at 5,100 rpm. In the image you will see that the Buick nail head production engine retains the intake side of the 216, but only half the piston ( half of a Hemi's piston dome) and moves the exhaust valves to the intake position whereby the exhaust path is highly restricted, Notice on the 216 that the lifter gallery and exhaust side rocker arm angles are unique and in this configuration is much better stability wise than the Chrysler Hemi. Too bad it never made production. see the link;

Buick-XP-300-engine.png

The nail head;

images?q=tbn:ANd9GcTVdQ013ERK1b7Xw8oZsIuzn7jvONMD3ILE6OkX6SGZIM3R1pUS

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Thanks for that link! Although the exhaust port appears to be "restrictive", what I see looks like an "anti-reversion step" in the floor of the exhaust port. That would help keep the intake charge "cleaner" and less diluted with residual exhaust gases as the new intake charge enters the chamber. In the '80s, anti-reversion cones were inserted in some brands of tubular exhaust headers to make carb tuning more efficient and build more power at the same time. Like Ford's Y-block combustion chambers, much of the '50s "high tech" was not fully developed until the '80s, it seems. Still, though, although smaller ports and valves are usually associated with "high velocity" ports, the middle rpm ranges would have benefited, as the upper rpm levels would have been compromised, needing the longer camshaft durations to help compensate for it.

As one Buick factory operative allegedly stated, when asked why Buick still had only pushrod engines when Olds had OHC engines . . . "For our customers, acceleration stops on the other side of the intersection." Don't need high rpms for that. Off-idle torque is what works in that situation.

Chevy used smaller intake valves in their medium duty "truck" engines. 1.72 intakes rather than 1.94s on the 4.00" bore engines. I found some dyno runs sheets for the 1971 model year, which included normal 1/2 ton 350 V-8s and similar C60 medium-duty 350s. There wasn't much difference in the horsepower or torque levels. Possibly the smaller valves gave better mid-range throttle response? Yet dual exhausts, 1.94 intakes, and a larger 4bbl made 50 (advertised) horsepower difference in 1965 Chevy 327 V-8s, with the same camshaft . . . 300 vs. 250.

And there's the issue of rod/stroke and stroke/rod length ratios of the Nailhead vs. the small block Chevy V-8s. Lower rod ratios mean the piston has less dwell time at TDC and exerts a stronger "yank" on the intake charge as it moves downward, which can help compensate for sub-optimal intake port design. Longer exhaust cam event duration can somewhat compensate for the poorer-flowing exhaust ports. A "package deal" for sure.

Enjoy!

NTX5467

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alright- these pics are from spring 2012 which is when i purchased the car in iowa.

the car was located around 375 miles one way from my home in nw wisconsin, found it via a craigslist ad.

i towed the car home with a car hauler trailer and my trusty 77 ford wood truck. the truck has a 300 6 banger in it with a 4 spd.

it was a heavy load for the old truck- max speed was about 58 mph the whole way back with the pedal to the metal most of the way...

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couple more pics

rear 4 trunk body mounts were rotted away...4 about equal hand sized rust holes... rest of trunk was very solid by wisconsin standards ha ha

paint code on car was aqua blue poly.. rear trunk lid was cream, same as front clip, so some parts came off another car maybe not sure of history...

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spring of 2012 was also remodeling house... was lucky enough to get 2 large free picture windows from someone down the road for the price of hauling them away...

we put the brown metal roof on spring 2011... best thing i ever did, snow slides right off. dont have to shovel it off any more thank goodness.

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back to buicks- i decided to start at the back of the car and work my way forward winter of 2012-2013 so i removed the gas tank and started to see what was what-

this was the worst rust i had to deal with...

PLEASE keep in mind i am not or have ever been a body man, a welder or whatever... i work in a warehouse, same one last 32 years and have done mechanical work but never any body work so my results are far from what many achieve on this forum. but maybe i can give some hope to the guy that is on a super low budget and may not have any skills, that you can still be involved in the hobby.

it baffled me how even to fix this without expending much money or getting someone to do it for me at first, but after some thought and lots of time spent on this and other forums i decided to cut out the rotted steel and piece in 1/4 inch angle iron to form the side angles of the body braces and then weld flat steel to the top and bottom.

the way i figure it, at least i am stopping the cancer from spreading and improving the structural integrity of the car which i will prove later.

keep in mind, whomever painted this car in the distant past just covered up all this rot with a piece of sheetmetal from a toyota hood...

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It is probably difficult for some on this forum to understand how anyone could do things on the cheap like this, but I know well of what you speak. I am taking this same approach with my '61 and I know the results will never be show quality, but then that is not what I am after. I just want to be able to drive a piece of history around and be proud in the fact that I did most of the work myself.

Also the '65 model big Buick's were among the most unique ones ever made IMO. With the excellent styling and single year instrument cluster design, they stand apart in these respects. If I ever get my '61 done, that is probably the next Buick I will be looking for. I do have a hankering to do an old Ford first though, just to be different. LOL

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Shift firmness is controlled elsewhere other than the vacuum modulator, from what I recall. "Mushy" shifts are just part of many GM automatic transmissions, compared to the "firm" shifts which some shift kits make happen.

A friend of mine did the B&M shift kit, about $50+ back in the early '80s. It was firm without the harsh shockloads which the $10.00 shift kits (same time frame) gave . . . manual L to manual 2 would chirp the tires on their Z-28s at part throttle.

One thing controlling shift firmness is the accumulator spring. The accumulator is in the fluid circuit to cushion the sudden "apply" oil flow for that circuit. Mopar Performance's shift kit (for the A-904 family automatics) says to leave the spring out all together. It did make things a little firmer and quicker, but not harsh by any means.

One of the old "shadetree" quick-shift-fixes was to drain the Dexron fluid out and put Ford Type-F fluid in its place. The Type-F fluid doesn't have the "initial slip before lockup" which Dexron has, so it makes for a nicer shift in the older THM400 automatics. I understand the blue B&M fluid has similar shift feel, for more $$$.

Remember, too, that a prime criteria for all automatic transmissions, back then, was the "imperceptible shift". You heard the engine rpm change, but didn't feel anything as the vehicle kept on gaining speed. The THM400 did a good job of this, too! Yet the other design criteria was to not have an overly-hard shift, even at WOT, plus a "easy engagement" into "D" or "R" . . . what the old Lexus midnight informercials called "shift shock". "Easy engagement" can be related to the basic line pressure of the transmission, which does have some internal adjustment to it.

Also remember Buick's customer demographics, back then, associated "smooooooth" with Buick, hence their love of the DynaFlow transmission for many years. If they'd wanted "more noticeable" shifts, they could have had an Olds with a Hydramatic, by observation.

You might start with a fluid/filter change. When I added some GM Automatic Transmission Conditioner to the THM350 in my '77 Camaro, it shifted a little more like my friends Z-28 with Type-F fluid in it. Slightly quicker and firmer. Remember, too, that your current fluid, if it's been in there for a while, might have gained a little viscosity over time. Newer and more "watery" fluid might ease the quickness of the fluid flow in the valve body, possibly.

To have the vacuum modulator correctly adjusted, you'd need a pressure gauge tapped into the appropriate fitting on the side of the transmission case, PLUS a GM service manual to tell you which line pressure range is operative for your general altitude . . . which is what it's purpose is anyway, to vary line pressure with altitude changes and lower related horsepower output due to the thinner air "up there".

Enjoy!

NTX5467

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Pretty nice looking car! I concur about the styling of the '65-'66 full-size Buicks. They look good in convertibles, too!

There's a LOT that can now be done with tools you can find at many auto supply stores, plus the various rust coatings and sealers. Much more readily-available now than in prior decades, it seems. Many YouTube DIY videos, too, plus the "Saturday morning" cable tv shows.

Good luck!

NTX5467

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Also remember Buick's customer demographics, back then, associated "smooooooth" with Buick, hence their love of the DynaFlow transmission for many years. If they'd wanted "more noticeable" shifts, they could have had an Olds with a Hydramatic, by observation.

NTX5467

They could have along with Olds, a Pontiac or Cadillac as all used the same automatic. The original Chevrolet Powerglide and Buick Dynaflow goals were the same. " A seamless no shifting of gears all done through the converter" . Remember the original Powerglide 1950-1952 started out in high gear and let the converter multiply the torque.

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thank you guys for the comments and encouragement...

i am a little angry at myself today as i took a bunch of pics when i was doing this work 2 years ago now, and for the life of me i cant find one of the camera cards some of the pics are on.

i snapped a few this morning to try and show a little work and will continue to look for the card...

here is a pic of the duluth mn - superior wisconsin harbor on my morning commute- 20 below this morning

that is lake superior off in the distance frozen about 20 miles out

also have been busy cutting firewood. i heat house pretty much exclusivly with wood. use around 5 to 7 cords a year. it must be split and put in woodshed by spring to dry over the summer for next winter.

house is much warmer and nicer with giant used windows in, more insulation and new vinyl siding.

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Edited by 65wildcatconvt
spelling again ha ha (see edit history)

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here is a picture of what the car looks like generally underneath before painting but after many cold hours in winter lying on your back with a wire brush , drill with wire wheel and various scrapers and screwdrivers to try and clean off as much loose scale and loose rust as possible.

but i always try and remember, "hey my labor is free" what else would i be doing? maybe getting into trouble.

this is a pic taken more towards the front of the car this morning so you can hopefully see what it looks like before and after paint.

tools used on whole project are wire feed welder, cheap 29 dollar jig saw, cheap 29 dollar electric cut-off tool and common hand tools.

as you clean and poke around like a dentist, you can find any weak spots and mark them to cut out if new metal needed.

the front half of the car seems to be in somewhat better shape than the rear... this is really solid and pretty clean by up north standards for 50 years old.

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Edited by 65wildcatconvt
add text (see edit history)

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Great car, and good looking pup too.. We had to put down our Husky Lab mix breed back in 2000 and still miss that dog. Anyway, good luck with the car, and all your other projects too.

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ok - i took these pics this morning of work and paint done 2 years ago.

this is a piece of steel welded over the rebuilt rear body mount. i sprayed some primer on it just to protect it as i want to go back and regrind some of my crappy welds when time permits, which is why i held off painting the entire trunk also.

remember my main goal was to keep the car drivable in summer if possible, so may of 2013 after taking out gas tank, rebuilding 4 rear body mounts and painting the rear 1/3 of car, it started to get nice out so i stopped work, put painted gas tank back in and car was drivable over the summer.

the gas tank will not have to be pulled again although there is some small cosmetic work to be done to make rear body mounts look better.

its hard to see but the steel is butt welded and should blend in decent with a little more elbow grease, which i can do as time permits in warmer weather while car is still usable.

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here is a pic of homeade body mount made from 1/4 inch angle steel and a pcs of plate first welded to it inside from the top.

these are the pics i have not found yet so i apologize for the poor photos.

basically i ran steel from the inside of the existing body brace after cutting out all weak metal. then followed the path to where the body mount connects to the inner rear fender if that makes any sense.

after getting this far, i then realized i can make another pcs of plate to tack over the angle steel from underneath, and with patience and some grinding i can most likely make it look very similair to a body brace.

the key thing for me is again, i can do that when free time comes up and car is still drivable.

the silver paint is 2 year old rust bullet, but not painted heavily around body brace as i know i will be working on it more...

any black paint is rustoleum spray satin black which is just sprayed over the rust bullet as time and money permit.

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now when i first got the car it ran poorly, but after getting it home and getting it running strong, but before doing any metal work i ran into a problem.

when acceleratng somewhat hard maybe half throttle or more, the car would have a shudder or almost felt like a wiggle to it.

at first i thought - ujoimt or driveshaft carrier issue or what? it just felt weird...

so when crawling around under the car i yanked and pulled on driveshaft, ujoints etc etc but everything seemed ok. so i just drove the car easy that first summer...

well you guessed it but after fixing 4 rear body mounts, i took the car out in the spring of 2013 and lo and behold 75% of the shudder was gone... now it would only have a mild shudder under almost full throtle starts.

so those rear body mounts were pretty much not mounting anything ha ha.

the rest of the shudder was eliminated as i moved farther up the car the winter of 2013- 2014. will try and post those pics next.

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How did this thread get so far from the original post? Someone needs to tell the feds about a hijacking.

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Didn't somebody ask for pictures? Evolved into "Me and My Buick"?

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To get back to the original subject.....DO NOT put off doing the timing chain and gears another day! The original question should have been.....what is the redline on my loose

chain and plastic teeth timing gear?

Edited by Seafoam65 (see edit history)

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Agreed! A worm OEM timing chain is a "non-ticking" grenade for the engine. Definitely "cheaper" than fixing or finding another engine (and then overhauling it before you put it back in). You NEVER know when it's going to "go", either. At 100K+ miles, I would hope it's already been done, but they are cheap enough (parts wise) to replace and then KNOW all is well in there.

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