Supercharged 455 Installation Completed
To All Interested Members 9-30-10
The status as of the end of September is that the supercharged 1970 Stage 1 Buick 455 engine was successfully installed in the 84 Buick Park Avenue. For those members who did not see the earlier threads from 6-7 months ago, it has an 8:71 roots blower and TA cam, pistons and valves. Some photos are attached to the end of this posting. I have been driving it for a few weeks at the end of summer here in Michigan. In about 6 weeks the first snow will hit and it will be retired into the garage until next April. I had it in three car shows and it draws a lot of interest and questions. There are not too many cars running 8:71 blowers (most are 6:71s), and even fewer of those are Buick engines. Therefore it attracts a lot of interest at car shows, or anywhere for that matter, even gas stations, especially from Buick fans.
I have about 600 miles on it, so it is just about broken in. It drives fairly well, although the stock 200-4R transmission is deteriorating rapidly. This is not unexpected, as I mentioned in a much earlier post that I considered it a throwaway trans that made the original installation much easier and quicker, with a direct bolt-up being possible. It started slipping in 2nd on full throttle bursts, and is now slipping in both 2nd and 3rd. I just got off the phone with Art Carr in California and over the winter I will probably go for his top-of-the-line 22 trans (for 700 HP) with his 2800 stall converter. This will be a necessary winter project. As of right now you cannot really go to high rpm and high boost because of associted trans slippage. I could a few weeks ago however, and it was impressive for a big, heavy car. I haven't gone over 6-7 pounds of boost yet because of the trans and the fact that the engine isn't quite broken in yet. This is a preliminary report.
As for the installation, it went fairly well, and I will report some problems that had to be solved. This may help some other members out there who may be installing 455 engines, blowers or both. First, even with compact shorty headers from TA, the headers almost touch the frame on both sides. In fact, they did touch on the passenger side and had to be flattened a little to clear. Second, the passenger-side brake line touched the header and had to be run through the frame instead of over the frame. Fortunately there was a frame hole already there that was used. Third, the stock radiator and clutch fan was used at first, with a 3-inch fan extension to clear the blower belt. My advice ... don't even plan on doing this. It fit (barely) but it would not cool the engine. The engine ran at 230 degrees and would overheat at idle. Then the entire cantilevered clutch-fan mass broke off during an accel and went through the radiator. The entire system was scrapped for a double core aluminum radiator and Flex-a-Lite Extreme electric fan (3300 CFM). This works like a champ and keeps the engine at 185 degrees. The cost of the engine project so far is about $13.4 K, including the cost of the 1970 buick 455 starting engine and $1.2 K for the custom radiator and fan. I am looking at another $3k this winter to upgrade the transmission and converter. I got some good deals on services like engine and exhaust installation, and did a lot of the work myself such as cleaning, rewiring and painting the frame and engine compartment, so I doubt that this type of project could be done much cheaper.
There is a lot of performance optimization to be done over the winter and next spring. I am still running on the MSD centrifugal advance of the distributor, and have not yet programmed the MSD 6AL-2 ignition module for custom advance curves. This will also be a winter project, as the mechanical advance has to be locked out and the ignition module hooked to my computer for installing the custom advance curves. Actually they are "retard" curves from some advance position of the distributor. The Edelbrock 750 carbs have to be tuned also, in conjunction with a chassis dyno once the trans is upgraded.
If any interested member has questions, suggestions or comments, please post them.
My best regards to fellow Buick fans,
Dave Harrington
Troy, Michigan