PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   67-79 Big Pontiac TECH (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=431)
-   -   1968 Catalina 2-door sedan 428 HO 4-speed (https://forums.maxperformanceinc.com/forums/showthread.php?t=791278)

DJ455HO 08-15-2022 07:44 AM

North,

Yes, original springs back in place. Thanks for the nice comments!

Dan

SD455DJ 09-02-2022 03:54 PM

It's Really Done!
 
5 Attachment(s)
The big 428HO Cat is a running driving car as of today...full of fluids and breathing through the Waldron exhaust system. Dan took some 'outdoor' shots that really show-off the Verdero paint in the sunlight. The stance looks totally factory correct...because it has it's original factory coil springs in it still. It's been a long road, but finally done...enjoy!

Dennis

1_Wild_Cat 09-02-2022 04:13 PM

Congrats -- That is insanely beautiful. Thanks for taking the time to share the process with the forum - a nice look at the process and what goes into this level of detail.

muscle_collector 09-02-2022 06:40 PM

man i love that car. what cam did you use in it? any chance of a video of it running? (especially out the exhaust)

CDN2PLS2 09-02-2022 06:53 PM

That's Cool! See ya in November.

Stuart 09-02-2022 08:14 PM

Looks great. It's interesting how the color looks in the shade versus in the sun.

SD455DJ 09-03-2022 10:26 AM

2 Attachment(s)
Quote:

Originally Posted by muscle_collector (Post 6369524)
man i love that car. what cam did you use in it? any chance of a video of it running? (especially out the exhaust)

Thanks Gary! The 428 HO dyno'd at 432 hp @ 5000 rpm and 502 lbft torque @ 3700 rpm with a real 068 cam and a true 10.75 to 1 compression through inferior flowing A-body RA manifolds with 2 1/8" outlets into 2 1/2" mandrel headpipes. It should make a little more torque & hp with the factory long branch manifolds. The heads are untouched and the block wasn't decked to preserve the select-fit piston letters stamped into the deck surface adjacent to each bore. The compression was made up with smaller dishes in the custom ordered pistons.

I have a dyno video, but don't know how to put it on You-tube and provide a link to it.

Dennis

muscle_collector 09-03-2022 01:31 PM

i noticed you mentioned a "real 068" cam. do you feel the crane reproductions of the cams arent quite like the gm ones? i have compared engines with the replacement cams running (ra3 ra4 and 455ho) beside a car that has not been touched and the original ones all sound a little bit nastier than the ones with an aftermarket replacement. and i never see the 69 ra3 4spd cams reproduced.

SD455DJ 09-03-2022 02:47 PM

Dan checked, and it the Melling SPC-7 '068' cam which is pretty darn faithful to the original. The Melling new version SPC-3 '744' copy cam has been severely 'watered-down' and has less duration at .100"-.250" than the factory specs. When you compare the new Melling SPC-3 to an original factory 744 and early version Melling 744 you'll quickly see the square shoulders are gone, so it is a bit tamer.

We've actually measured (degreed) factory 068, 744/SD-Y, and 041 cams to compare to the Melling's offerings and they are spot-on, except for the latest '744'/SPC-3 cam.

I will say that we are impressed with the Summit 2800, 2801, and 2802 cams. They are a great value for the money spent and hard to beat when on a budget.

Dennis

joegpho 09-07-2022 04:05 PM

Quote:

Originally Posted by SD455DJ (Post 6369642)
Thanks Gary! The 428 HO dyno'd at 432 hp @ 5000 rpm and 502 lbft torque @ 3700 rpm with a real 068 cam and a true 10.75 to 1 compression through inferior flowing A-body RA manifolds with 2 1/8" outlets into 2 1/2" mandrel headpipes. It should make a little more torque & hp with the factory long branch manifolds. The heads are untouched and the block wasn't decked to preserve the select-fit piston letters stamped into the deck surface adjacent to each bore. The compression was made up with smaller dishes in the custom ordered pistons.

I have a dyno video, but don't know how to put it on You-tube and provide a link to it.

Dennis

OK - now I have to figure out why my 428 HO dyno'd at 385 hp and 480 lb-ft of torque.
Is your block bored +.030", like mine is? My pistons are Keith Black and the cam is a Comp Cams XTREME Energy XE262H. I wanted custom pistons but my builder didn't think such were necessary.
Great car, Dennis! See you at Stanton! (I'm bringing my 68 H/O.)

SD455DJ 09-07-2022 05:04 PM

Quote:

Originally Posted by joegpho (Post 6370595)
OK - now I have to figure out why my 428 HO dyno'd at 385 hp and 480 lb-ft of torque.
Is your block bored +.030", like mine is? My pistons are Keith Black and the cam is a Comp Cams XTREME Energy XE262H. I wanted custom pistons but my builder didn't think such were necessary.
Great car, Dennis! See you at Stanton! (I'm bringing my 68 H/O.)

Hi Joe! Yes, Dan's 428 is +.030" over. I think that cam is holding your engine back from 400+ hp/500 lb-ft torque. Looking forward to seeing you next week (...already! Where did summer go!)!

Dennis

DJ455HO 09-09-2022 10:47 AM

2 Attachment(s)
This morning I grabbed Scott's Intercomp E-Z Weigh Scales to see what the Catalina weighs. It came in where I was hoping. Not much worse that a 70-72 moderately equipped GTO (auto & AC). The car had 9 gallons of fuel in the tank. Dan.

'ol Pinion head 09-09-2022 11:17 AM

So SWEET!

Dan, the '68 Cat going to make its debut next weekend at the track?
Or wait til Nov @ MCACN?

DJ455HO 09-09-2022 04:39 PM

I'm going to debut it at MCACN in the Full-sized Four Speed class.

Maybe next year it will see the track. I still have some small things to sort out before I feel comfortable having fun with it.

Dan

north 09-12-2022 02:49 PM

Gorgeous end result! 3,986 is surprisingly low, shows the benefit of the sedan (rather than hardtop) bodystyle and low option count. I weighed recently my 69 GTO hardtop (4spd, AC and heavily optioned) and it weighed 3,885 (2,300 front and 1,585 rear corrected to the same fuel level as yours). Obviously things like AC are a big hit and my car has a lot of other weight adding items that yours doesn't like 8 track, stereo two piece radio with rear speaker, power windows, locks, seat and antenna etc. I have a pretty basic 69 Catalina two door hardtop I should weigh, it is a base engine, single exhaust auto trans with power drum brakes and steering, not much else. At the top of the weight spectrum I should weigh my 69 Bonnie wagon, fully loaded, I'd guess its closing in on 5k.

Stuart 09-12-2022 03:33 PM

Given the large physical size of cars back then it's easy to assume they were very heavy, but remember they were basically big hollow boxes. :) There were no side impact beams or 5 mph bumpers or huge amounts of wiring for computer controls or any of that sort of thing.

north 09-12-2022 07:47 PM

True, 69 big cars (and the GP) were the first to get door beams and the post sedan and coupe bodies often used a lighter frame than for the hardtops since the body provided much more rigidity.

Mark Simiele 09-13-2022 07:46 PM

Very nice, car looks fantastic

ursusarctos 09-14-2022 10:57 AM

Quote:

Originally Posted by joegpho (Post 6370595)
OK - now I have to figure out why my 428 HO dyno'd at 385 hp and 480 lb-ft of torque.
Is your block bored +.030", like mine is? My pistons are Keith Black and the cam is a Comp Cams XTREME Energy XE262H. I wanted custom pistons but my builder didn't think such were necessary.
Great car, Dennis! See you at Stanton! (I'm bringing my 68 H/O.)

joegpho,
Do you have a link to your engine & dyno results?
Was the dyno done with steel headers or iron manifolds (which ones?), and any pipes/mufflers?
Compression ratio?
Corrected to SAE-J-607 (the old gross 60F 29.92 dry sea level)?

I too am wondering why the dyno results are so different.

SD455DJ 11-20-2022 10:22 PM

Well, the terrible winter weather we had last week prevented us from hauling the Catalina to MCACN. We decided not to risk the just completed Catalina on the icy roads, but still drove down to honor our judging commitment. We were bummed by the rotten weather that zeroed right on this one weekend! A lot of people were disappointed that were hoping to see the finished car in person, but we were equally disappointed too!

We didn't get New York's 77" of snow, but we had a good 10"-12" over the weekend here in West Michigan.

Dennis


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