[blown 68]

well, right before i took the engine out of the 68 for this rear main issue, http://tinyurl.com/33pne4 something started makin' a squealin', not the good kind, (like my tires), but like nothing i'd ever heard, luckily, i was only a few blocks from home, and it was rpm sensitive, so i rode it out, hoping whatever it was would make it there. (probably not the smartest thing to do, but hey, a calculated risk..)
sooooo, i pulled the engine, alternator checks out, water pump checks out, PS pump checks out, idler checks out, only thing left: blower. i took it down to my friend who built it, (he's been a bds rep for twenty plus years), we pulled the back cover, low and behold, a bad bearing on the drive rotor locked up a bit, just enough for that baby to start spinning in the bearing plate, (refer to 'makin' a squealin' above. ) which in turn wallowed that sucker out. could have been fixed, he showed me the repair, it's a metal collar, like a slice of pipe, they heat up, and press around the bearing boss to tighten up clearances on the bearing itself. then i saw a replacement back cover, with the fins on it, and decided, what the heck, go for the pretty one, and not worry about the repair on the old plate. this one has little removable covers over each bearing too, in case you want to check on them periodically.
anyway, just wanted to share, i always like looking at other peoples stuff, so, in the next month or two, i will share some pics of the car going back together, and some of my stuff. for now, here is my nifty blower backside, and the 'ol workbench, and mama waitin' for her new ticker...

[johnta1]

Glad you found the 'squeal'.

Maybe instead of when you replaced the rear cover, you should have replaced it all with a 8-71 ?

[Batman]

Nice!!! Gotta love it when it turns out to be something simple.

I like the different look of the chrome nosepiece w/hideaways. Not something you see every day

[mchell]

Unreal to see that thing sticking out of the hood!.......Dang!!

[blown 68]

Originally Posted by johnta1

Glad you found the 'squeal'.

Maybe instead of when you replaced the rear cover, you should have replaced it all with a 8-71 ?

well ya know, it crossed my mind. and then i was thinkin' about better heads, then i was thinkin' about an IA II block, then i was thinkin' about the new billet cranks, ah, you know the drill..................so, a new endplate it is.......for now.

[goquick]

Looks great! I'd say you made the right choice.

[360Rocket]

damn, hate to see my favorite car come up lame. Keep us updated as you know we love to watch build ups. Sorry that happened and good luck with the build.

[blown 68]

well, not exactly an update on the engine, but i was out in the shop tonight, taking some pics of brakelines for another thread here, and i thought, what the heck, how about some shots of the inside of the ride, so you can see my perspective while driving this monster..............oh, and an inside look down my offy blower manifold, in case anyone wondered what the plenum etc, looks like.

ps, the gauge cluster is the usual suspects, oil, temp, volts, and the little guy on the right is my a/f ratio gauge, by innovate, the 'all the works in the cable' model. (brain fart on model number....) and the ol' classic, a pontiac manifold vacuum gauge on the console, (yes i know it doesn't belong on this year, but neither does a 6-71. ) it is plumbed at the base of the carbs, on the carb adapter plate. i have a boost/vacuum gauge, plumbed to the intake, with a 'tattle tale' in one line, and a realtime line, plumbed with a three way valve, so i can read both, and have an above and below reading of the blower. yes, i like knowing what;s going on everywhere . next to the boost/vacuum gauge is a fuel pressure gauge, (matching autometer, like the ones pictured), both mounted outside, side by side at the base of the rear of the scoop.

the leds on the gauge panel from left to right are: green, ignition on,(have hidden cutout switch), amber, indicator for aux. fuel pump, with manual turn on switch, (also wired into my kickdown switch), and red, indicator for my dual fans when they come on, and a manual turn on switch.

oh, the shifter is a b&m megashifter, custom mounted in the factory console, with a 'ballvalve' shift knob, made of stainless.(thank you work).

just for fun, wanted to share, enjoy folks...........

[blown 68]

well, went to the machinist's today,(and forgot camera, arghh!) to drop off the new solid lifter cam, lifters, and oil pump. the conclusion we both came to mutually, is that i am trading him my .060 over hardblocked 455 block and aluminum caps, for one of his cores, which just got a fresh bore of .060, and is hardblocked, with new billet steel 4 bolt caps.
everything looked alright upon teardown, she is still running a wee bit on the fat side, i'm assuming that is my warm up and idle time, the car spends alot of time at part to zero throttle, there just isn't alot of places to put 600 horses to the ground around here 'cept for the track, and with my rear main oil leak, that was a no-no in my book. so, i am going to tweak my idle/part throttle settings, i was in the 12.0 to 1 area for warmup, and mostly in the 13.00's and low 14.00's for cruising, but maybe that is still too rich. who knows. it's all a learning curve for me right now anyway, with the blower setup. i might dyno it again, just to see how the new cam does, and check for anything outside of the norm, before it goes back in the car for the FIFTH time. .
well, that's all for now, got a gig tonight in seattle, might see a few board members there, according to another post in the lobby. hopefully the engine gets built next week, and i will have more photo's, and progress report.
'til next time folks,

davey

ps, my machinist just finished dyno'ing one of his friends engines that they just went through, a 601 kaufman, 1100 horses on alcohol. can't wait to hear that one............

[360Rocket]

hey, any updates lately???

[blown 68]

hello folks, how do. well, i am going into the dyno session today, for my freshly built engine, got her all setup yesterday, and we are running it today. same basic engine, but a bigger solid cam this time around, i will be sure to post the info, and some pics,(going to try and video too, but i will have to learn how to upload vids....), so, wish me luck. hopefully this time around we have everything sorted, i feel we do, so, should be a good day. alright, i will talk to you all in a bit, later this evening with the days events, have a great day.............

davey

[goquick]

Thanks for the updates.

[johnta1]

Sounds great.

Can't wait for the numbers.

[blown 68]

hey hey! well, got alot of tuning done, a ton of new knowledge was gained,(isn't what that is all about anyway? i love it!), and overall, a fun day of pounding on a blown pontiac. (please don't ask me about the moisture under the rear main..... ).

so, the combo is pretty much the same, a 4 bolt steel capped 455 block bored .060 over, eagle crank, eagle h-beam rods, ross forged pistons. 7.9 to 1 compression, 6H d-port heads with a mild clean up in chambers and ports, 129 cc's, with H.S. 1.65 roller rockers. ferrea stainless 2.11's and 1.77's

the cam is actually a score from Supergas Dil, (thank you! sounds WICKED). a lazer solid flat tappet. intake is 295 advertised, 261 @ .050 duration, .589 lift w/1.65's. exhaust is 310 advertised, 272 @.050 duration, .589 lift w/1.65's. 112 lobe seperation, with 4 degrees advance ground in on a 104 int. centerline i believe?(going from memory, you know how that goes... ).

distributor is a factory one, with 4 degrees in it,(8 at the crank,) running 22 to 24 initial, 30 to 32 total, all in by 3500, nice and slow. a pertronix unit takes care of the points.

up top is an old offy (blower conversion) manifold (blocked exhaust crossover) with a one inch spacer (distributor clearance), with a 6-71 GMC huffer @ 3% underdriven(32 tooth up top, 31 down low, 1/2" pitch). on top of that is two 750 edelbrocks, purple springs, (5 inches i think) 110 jets in the secondaries, 112 in the primaries, with stock metering rods.(can't remember numbers, manual choke carbs..).

we warmed her up, got the initial timing set, made a few power runs up to 6000 rpm, (3000 rpm start on all runs) to break her in, and seat the rings. she picked up about 3 to 5 horses per run, just settling in. after about 4 runs things leveled off. we checked the oil, looked good, nothing in the filter, good to go.

here are some things we found: the engine liked more timing. i started out at 28 degrees total. 614.7 horses @ 6200 rpm, 614.7 lbs/ft @4600rpm (horsepower didn't drop off, but was leveling, so i called that the shutoff rpm, as i don't plan to spin it higher than that anyhow). bumped the timing to 31 degrees total, and picked it up to 636.7 @ 6200 rpm, with 630 lbs/ft at 4500 rpm. 22 horses for two degrees, i didn't think it would jump that much, but there you go. i didn't push further with timing, this is all on 92 octane pump gas. 8.2 to 8.6 psi boost was the norm @ 6200 rpm.

didn't need to do too much jetting changes from last time, numbers looked ok. a smidge rich down low, part throttle, and a little fat on top, which is fine by me. better rich than lean with the 'ol blower. i like to melt my pistons OUTSIDE of the engine.

so, after some tweaking, and comfortable with what we had tuning wise, we decided to run 3% over, by changing the top pulley to a 30, crank still 31. at this time, we put it 111 octane leaded fuel. timing still at 31 degrees. biggest power of the day, 653 horses @ 6200 rpm, 641 lbs/ft @ 4500 rpm. this was @ 9.5 to 10 lbs of boost. we started getting spikes, up and down, at the very top, suspecting detonation as a possiblity. we had some belt slippage after we swapped pulleys, had to really reef on that idler arm, thought maybe that was a possibilty too, but after tightening, still had spike like drop offs in power readings. several runs like this satisfied us.

so i went back to 3% under, same timing of 31 degrees.
here is an intersting find:
now power was down from previous runs by as much as 13 horsepower, and 20 lbs/ft.
one of the techs said, he has seen many times when an engine is built for low octane, power drops off when you give it the good stuff. i questioned it, beings as i am boosting it, but back to back runs confirmed this data. may car is a cheap date at the pump, she likes the cheap stuff. sweet!

i did not try a 3% over on pump gas, i did last time, but the funny spikes during our attempts earlier on the good stuff made me shy away from doing so.

well, besides the fact that there were a few drips coming from the rear, right off the edge of the pan at the lowest point of the arc around the rear main cap,(not slinging it at all, just a drip right at the edge of the pan, which was fully rtv'd in the seam and all around), it was a great day of beating on a pontiac. i must say, that thing rumbles like nobodies business, you could feel it in the floor of the shop. sounded great, ran like a raped ape, and was a good time for all of us.

i video'd it, the camera has a digital video out, but the only cord i have does not go into a usb port, but another one.(new macbook) i plugged it in, but i didn't see it register like when i plug my camera into a usb port. so, if someone smarter than me wants to pm me, maybe i can post a vid.

allright kids, that's all i got for now, hope you find it helpful and or interesting, or just plain fun. below are some pics, the engine on the dts (sp?) dyno, and two of the printouts. i am still learning along the way, but it's a blast. thanks p-dude for all the tips tha helped me get here, and thanks to all on here for sharing your knowledge with me, i am trying my best to give some right back...........

[flamedabone]

That is so kick asss. Your mill looks killer. 650 horse is Ok too......

Hurry up and get that thing back in the car and go scare teh piss out of yourself.

BTW, I haven't been to the dyno, but I have about 2000 miles on mine and she purrs like a kitten so far.

See ya, -Abone.

PS. You have GOT to get the video figured out!!

[johnta1]

That is awesome HP .

As flamed said get it in the car and see what it'll do.

[goquick]

You are going to have some fun with that!!! Congrads

[Jack Gifford]

Glad it was 'uneventful', and everything went well.
"Belt slippage" is hard for me to imagine- could you actually observe it? All the years I ran a 6-71 in competition, I never [intentionally] ran any tension on the belt- always tried to set it so the slack would all be out when the engine was extremely hot. Although mine was a mild setup, the belt had to work a little harder than yours- 8% over crank, 12-13 PSI, up to 9,000 RPM. Just curious how you identified "belt slip".

P.S. Is there any compressibility to your intake or blower gaskets? Trying to think of anything that could allow a change of pulley center dimension under stress. My setup used O-rings for intake & blower, so no possible gasket compression.

Looking back at your pictures, I see quite a bit of cantilevering of your top pulley- mine is almost snug to the blower's front cover.

[blown 68]

Originally Posted by pontiac jack

Glad it was 'uneventful', and everything went well.
"Belt slippage" is hard for me to imagine- could you actually observe it? All the years I ran a 6-71 in competition, I never [intentionally] ran any tension on the belt- always tried to set it so the slack would all be out when the engine was extremely hot. Although mine was a mild setup, the belt had to work a little harder than yours- 8% over crank, 12-13 PSI, up to 9,000 RPM. Just curious how you identified "belt slip".

P.S. Is there any compressibility to your intake or blower gaskets? Trying to think of anything that could allow a change of pulley center dimension under stress. My setup used O-rings for intake & blower, so no possible gasket compression.

Looking back at your pictures, I see quite a bit of cantilevering of your top pulley- mine is almost snug to the blower's front cover.

i think the deal there was, after i swapped pulleys, i may not have tightened the idler arm as tight,(attached to the snout), and when it was pulling harder because of the increased speed,(you could audibly hear the difference between the two pulleys, only two teeth apart), i think it pulled the idler down a bit, and at the top end of the run, i saw the belt go bump........bump....bump..........as it was skipping a tooth here and there. maybe three times total. not truly 'slipping', i should have worded that different, 'skipping a tooth' here and there would be more accurate,. anyway, an adjustment and a heavy snug, and it was fine.

it's amazing how much the aluminum grows, between the manifold, the spacer, the blower, and the pulleys. you can have the belt with ample side to side slack, maybe an inch or so, and two runs later, it would be tight as a drum, and i would have to loosen it up a bit. then we do some tweakingelswhere while the engine was off, and the airflow through that room would cool off the engine so fast, it would be loose again. couple runs later, tight. amazing really, i didn't realize aluminum grew so much under heat............

davey

[Silver Judge]

Way go, those are excellent numbers
The torque #s down low @ 3000 RPMs are KILLER Davey, Wow
Now you'll be fishtailing around town in no time

I hope you 're bringing the wicked '68 to Tiger Run, I'd love to see it with this new
nasty set up