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#21
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SD455J
My former '69 Bonneville YH 428 was re-built in a similar manner. It got a .030 overbore, a .067 equivalent Comp Cam, new pistons with a 9.5:1 CR, stock intake, balanced crank, fuel pump, new timing gear and chain, main seal, HEI kit, rebuilt Q'jet, log manifolds and dual exhaust. I had a set of original 428 HO long branch manifolds and the large volume air cleaner intake that went with the car when I sold it. I never had it dyno'd but would expect the numbers to be roughly similar as your said. Whatever the exact numbers it ran exceptionally strong and smooth. New owner is installing the Long Branch manifolds with stock 2 1/4" pipes (2 1/2" from the manifolds tampered down to 2 1/4" after the mufflers) which will boost its performance even more.
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'69 Bonneville convertible Warwick blue/ parchment interior 53 option accessories 2 more to go :-) |
#22
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One of the now defunct Pontiac magazines did a comparison test on #15 heads vs. some other large valve heads. I don't remember the exact large valve heads, but the 15s actually did quite well and had good breathing. The main drawback was the pressed in studs, and even that was only an issue if larger lift cams and heavier springs were used.
I quit using the #15s years ago (80s) because the engine pinged a lot, (even after a total stock rebuild) after they eliminated high octane leaded fuel. Back then, the local expertise about cams to compensate for that was not easy to find. And there was no internet to discuss with other Pontiac people. |
#23
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pressed in studs are of course easily addressed if that is a concern due to high stress use of the car. They can be drilled for screw in studs or they can be pinned.
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'69 Bonneville convertible Warwick blue/ parchment interior 53 option accessories 2 more to go :-) |
#24
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Quote:
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#25
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David & Blubomber, Here is the dyno sheet (also tested it as a 2-bbl), pics of the motor, new rear end and car.
Dennis |
#26
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...forgot the car...I appologize for hijacking North's thread...sorry.
Dennis |
#27
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I switched from the #15 to lower compression. I battled the pinging for 2 years. It was worst in the summer with the A/C on, but living in south Florida, summer is at least 1/2 the year. I switched to 96 heads from a 1971 or 1972 GTO. That lowered the compression enough that it never pinged again. But the engine was no slouch with the #15s.
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#28
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My Bonneville had the heavy duty radiator as std equipment with A/C. I still have the Super duty radiator from the Bonneville Brougham convertible 428 HO car I parted several years ago. Pretty rare. I know the aluminum rad's are more efficient but I am a sucker for original equipment.
I found the same thing driving my car around central VA in the summer. It would ping in the summer (very hot and very, very very humid) when pushed hard but if I waited until the sun went down and cooled things off a bit she really woke back up. Of course the best was in Nov to Jan. clean, cool, dense air.
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'69 Bonneville convertible Warwick blue/ parchment interior 53 option accessories 2 more to go :-) |
#29
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Quote:
TH400, A/C, duals, PDB, PS, Brougham (includes PW), six way seat, power trunk, AM radio, rear speaker, power antenna, tilt, cruise, gauges, soft ray all, Cordova top, wire wheel covers, deluxe belts, lamp group (reel out hood light and cornering lamps), door edge guards, rear defog, remote mirror, visor mirror, headrests, mats front and rear, J78 white walls, HD batt, HD air cleaner, Instant-aire. It was ordered with power locks but they didn't happen. I added a woodwheel and I'm waiting for a repair service to install a spare 69 B car stereo radio with the correct dual rear speakers.
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My Break Away Squad 1969 Fbird (Base, 350 & Sprint Cvt’s - 400HO & TA Hardtops) 1969 LeMans (2dr & 4dr Hardtop and a Cvt) 1969 LeMans Safari 2 seat Wagon 1969 GTO (2 Cvt, 2 Hardtops & Judge Hardtop) 1969 Catalina (3 Cvt’s & a 2dr hardtop) 1969 Ventura 2 Seat Wagon 1969 Executive 4dr Sedan 1969 Bonnie Cvt 1969 Bonnie 3 Seat Wagon (2 of them) 1969 Bonnie Brougham (4dr Hardtop & Cvt) 1969 Grand Prix SJ (2 of them) 1969 2+2 2dr Hardtop (Canadian model) |
#30
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btw no apologies required for the engine mod takeover of the thread, I'm doing the engine in my Bonneville convertible as we speak, 428HO with original 62 heads but I swapped in a 455 crank and cast pistons that result in 9.5 compression. I can't think of the brand but the cam is basically a 067 but with greater lobe separation to address octane concerns, I've run the same cam in a 400 with similar compression and like how it runs and sounds. We have 94 octane here but it has ethanol so we have to run 91 octane to get pure gas.
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My Break Away Squad 1969 Fbird (Base, 350 & Sprint Cvt’s - 400HO & TA Hardtops) 1969 LeMans (2dr & 4dr Hardtop and a Cvt) 1969 LeMans Safari 2 seat Wagon 1969 GTO (2 Cvt, 2 Hardtops & Judge Hardtop) 1969 Catalina (3 Cvt’s & a 2dr hardtop) 1969 Ventura 2 Seat Wagon 1969 Executive 4dr Sedan 1969 Bonnie Cvt 1969 Bonnie 3 Seat Wagon (2 of them) 1969 Bonnie Brougham (4dr Hardtop & Cvt) 1969 Grand Prix SJ (2 of them) 1969 2+2 2dr Hardtop (Canadian model) |
#31
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Thanks North for listing the options (by memory no less). I have really grown fond of the B-bodies of all varieties and years...hi-po, lo-po, 4-dr, 2-dr, hardtop, sedan, convert...you just don't see that many anymore.
Dennis |
#32
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Quote:
Dennis |
#33
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By memory the cam is between the 2800 and 2801 in terms of duration and lift. I might be wrong about the compression, maybe it is more like 9 and a quarter.
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My Break Away Squad 1969 Fbird (Base, 350 & Sprint Cvt’s - 400HO & TA Hardtops) 1969 LeMans (2dr & 4dr Hardtop and a Cvt) 1969 LeMans Safari 2 seat Wagon 1969 GTO (2 Cvt, 2 Hardtops & Judge Hardtop) 1969 Catalina (3 Cvt’s & a 2dr hardtop) 1969 Ventura 2 Seat Wagon 1969 Executive 4dr Sedan 1969 Bonnie Cvt 1969 Bonnie 3 Seat Wagon (2 of them) 1969 Bonnie Brougham (4dr Hardtop & Cvt) 1969 Grand Prix SJ (2 of them) 1969 2+2 2dr Hardtop (Canadian model) |
#34
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I drive these type cars very sedately, what I want is nice smooth idle and effortless low-mid pull. The car is heavy and only has 3.08's which equate to 2.73 in typical musclecar type wheel circumferences.
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My Break Away Squad 1969 Fbird (Base, 350 & Sprint Cvt’s - 400HO & TA Hardtops) 1969 LeMans (2dr & 4dr Hardtop and a Cvt) 1969 LeMans Safari 2 seat Wagon 1969 GTO (2 Cvt, 2 Hardtops & Judge Hardtop) 1969 Catalina (3 Cvt’s & a 2dr hardtop) 1969 Ventura 2 Seat Wagon 1969 Executive 4dr Sedan 1969 Bonnie Cvt 1969 Bonnie 3 Seat Wagon (2 of them) 1969 Bonnie Brougham (4dr Hardtop & Cvt) 1969 Grand Prix SJ (2 of them) 1969 2+2 2dr Hardtop (Canadian model) |
#35
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Quote:
Dennis |
#36
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I don't remember the exact figures but the cam sounds about right. What I do know is that even with the lowered compression, pump gas, and small valve heads I surprised more than a few younger fellows driving newer Mustangs and Camaros. Re-building the carb and the accelerator pump on the Q'jet was probably the most important factor though. The car had a little "hiccup" on hard acceleration up to that point.
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'69 Bonneville convertible Warwick blue/ parchment interior 53 option accessories 2 more to go :-) |
#37
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Very nice! I honestly would recommend a Real Original 067 cam
Its 200in 213ex .410-.410 113lsa 113ilc these were a very good cam for the big cars and added a lot over the 066, i have had both in my 69 370hp 428 Grand Prix and the 067 was much stronger, i highly recommend using at least 1.65 rockers with it to get aprox .448 lift The 066 was the grocery store max power below 4000rpm cam lol Many try to say the 066 and 067 are the same but its not true! I Had Howards Grind me a Higher Lift Version and it worked great in 389-400-428 motors in big cars! Specs were 202in 215ex .458in .465ex lift 113lsa 268-280 advertised It pulled from idle to 5000-5200rpm and had a nice Heavy idle sound My 72' came with a 2bbl 400, number 7J2 Heads with 1.92in 1.66ex valves Mine had 65k when i got it last year and even though my car has a measured compression ratio of 8.00:1 it surprises people and so far runs 15.8-15.9 in the 1/4 mile, not a rocket Ship but more than enough to blow the tires off ! Here is what i have done, these changes Made Huge Differences! First thing i did was a tune up and i rebuilt the 2GC That helped a bit Next i took off the timing solenoid and set the total timing to 36* with the vac advance disconnected, This was a Night and Day Change! Next after tuning the 2bbl a bit i said F-it and i got a Q-jet from a 77 trans Am, completely redid everything, i build Q-jets as well as engines for a living. At the same time i got a 72' iron intake, you must make sure you use the correct intake/and gaskets because the Ex crossover is different up to 72' I port matched it to standard gasket size I also Added a Pertronix Style ignition to the car Man its a whole Different Car from when i bought it! It went from i would guess 150-160hp stock to i would say 230-240hp With those changes, it now Roasts the tires if i stand on it and it pulls much harder! 72' 400 2bbl specs 8.00:1 compression, small valve heads, 254 cam .379in .408ex 196in 204ex duration, 269-277 advertised duration, 113lsa 113ilc Very Anemic stock but being a 72' 400 it still had the better pistons so its identical to most any 400 before it so i am adding some mods here in the coming weeks fwiw Adding 270cfm #17 heads, compression with be 9.35:1, summit 2801 cam 214-224 with .489in .511ex lift 112lsa 108ilc budget deal! HS 1.65 rockers, fully ported Iron 4bbl and 850 Q-jet Long 4 tube headers, dual 2.5" exhaust, 22-2400 stall with 3.42 gears and a trutrac posi, plus a ratchet shifter of course! Because of the heads it will be 405-415hp and 455-465tq Just something to play with until my 467 is done!
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Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#38
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All good info. Just goes to show how much potential is in these motors. Adding the Pertronix HEI to the distributor did help, new coil, good wires, plugs, and of course timing are essential. Good radiator and water pump are also important. With all that said if the motor is well maintained and all set up correctly these are very potent mills. The genius of the Pontiac engineers to be ale to make one block have so many variants and be able to perform wonderfully across all of them. Truly from mild to really wild. No other manufacture had such a multi-talented block.
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'69 Bonneville convertible Warwick blue/ parchment interior 53 option accessories 2 more to go :-) |
#39
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I hear some builders saying step up to Modern Parts, the old pontiac parts are Ancient and you will leave a lot of power on the table, Dont use those Old School Cams lol i say thats alright they havent built a new pontiac engine in 35 years either and we still use those!
Other than Buick,Olds, and Caddy Pontiac understood how to move a heavy car! There is still a few things we have yet to improve on! The RA4 cam is amazing in applications that can use it and you would be hard pressed to get a modern cam the same size to out perform it! The 068 cam is Probably the most versatile street performance cam made for a pontiac The Factory 4bbl intake is still the best intake that fits under all hoods and was designed during the SD421 engine program! Machined Combustion Chambers Doweled main caps, still the best way to locate caps. Anyways, yeah Unbelievable how smart these guys were! BUT i will never understand why they used cast rods! Sorry for the high jack!!!
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Build it Right Build it Once!!! Just another Engine Builder from the Northwest lol |
#40
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Update on my 4door Bonnie;
Productive winter, put a nice set of 235/75/15 goodyears with a 3/4 whitewall as the tires on the car were early Michelin X radial tires from the late 70's. Also popped on a Waldron exhaust set up, clone of the original dual system the car was ordered with. Fit beautifully, but they don't offer any factory style hangers. I was able to salvage the four original hangers by changing out the rubber from the universal hangers and fit it to the dry factory ones. I also found a really nice original nose and had it and the rear valance painted (was banged in). Came out nice and blends in better than expected considering the fading of the hood and trunk. Today i spent the evening swapping out the factory AM for an original 69 2piece stereo and an 8 track, took about 5 hours but went very well. Started by replacing the blown factory rear speaker and added a second rear (both were reconed originals) with the factory insulating boxes. Had to pull the glovebox, ashtray etc to mount the multiplex properly (over the glovebox) and run the 8 track cables. Carefully measured the factory installed 8 track in my Bonnie ragtop and located the mounting bracket properly. Amazingly all worked great right off the bat. Sounds really nice, Howard Foulds has done a bunch of refurbishing of radios and 8 tracks for me and as always his work is top notch!!! Funny thing is 69 B bodies had the 8 track unit always in black while the A, F and G cars were all color keyed to the dash pad color. I guess they figured the black 8 track matched the black dash bezel area. Next is to pull the engine, clean it up and do all the gaskets and seals etc, detail the engine bay a bit and drop the engine back in ( someone put in a HEI distributor and painted the upper part of the engine ford blue but left the original distributor in the trunk complete with Q3 68 factory dated wires). Engine runs so well that I won't rebuild her. After that is a front end freshening, springs are still perfect ride height wise but some bushings look bad.
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My Break Away Squad 1969 Fbird (Base, 350 & Sprint Cvt’s - 400HO & TA Hardtops) 1969 LeMans (2dr & 4dr Hardtop and a Cvt) 1969 LeMans Safari 2 seat Wagon 1969 GTO (2 Cvt, 2 Hardtops & Judge Hardtop) 1969 Catalina (3 Cvt’s & a 2dr hardtop) 1969 Ventura 2 Seat Wagon 1969 Executive 4dr Sedan 1969 Bonnie Cvt 1969 Bonnie 3 Seat Wagon (2 of them) 1969 Bonnie Brougham (4dr Hardtop & Cvt) 1969 Grand Prix SJ (2 of them) 1969 2+2 2dr Hardtop (Canadian model) |
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