Pontiac 400

SSS's Pontiac 400 Engine

The Pontiac 400 engine was obtained by the club in approx 2004 as a spare engine. It was installed into the "Bus Winch" in 2008 after the Oldsmobile 403 that had been installed broken a conrod, that in turn destroyed the block. The Pontiac engine always starts easily, even after being left untouched for months at a time, and gives good launches.

Situation

• The Pontiac Engine was removed from the Y/Reserve/Bus winch in August 2019. It still worked OK (with reservations about total power), but whilst Skylaunch finished the winch rebuild, it made sense for them to install the Chevy 454 Big Block the club had as a spare - this ensures adequate power and spares availability for the future.
• 29th June 2020: The Pontiac 400 engine is currently in storage being kept as a spare engine. If a fault develops with a winch engine the Pontiac could be installed, but would require modifications to engine mounts, exhausts, etc, etc.

Introduction

The Pontiac 400 was built in the USA between 1967 and 1979, produced power outputs between 200 to 300 BHP and was used in cars such as Pontiac Tempest, GTO, Firebirds, etc. Spare parts are still readily available for this engine, especially in the States. There are a number of companies in the UK who can supply parts off the shelf.

Sources of Information

• A simple web search can provide lots of useful information.
• The Haynes Manual, Number 19025 "Buick, Olds, Pontiac Full Sized RWD models from 1970 to 1990" covers this engine. The club has a copy - should be on the bookshelf in the clubhouse. * Ultimate American V-eight engine data book, 1949-1974, Books 1949-1974 By Peter C. Sessler. Has information about all American V8 engines, a bit of background, etc, but - most usefully - how to identify and date an engine. Has block, head and manifold castings number information - an invaluable book when buying a replacement V8 engine. Also gives power and torque output data.

SSS's Pontiac 400 Engine

With data taken from the Ultimate American V8 Book, the engine has been identified and its year of manufacture found.

• Block casting number: 500557. Identified as 1976 Pontiac 400 engine. Further Block markings: GM-5
• Cylinder heads: Casting numbers: 6X - identified as 1976-1977 Pontiac 400. Further head casting numbers: GM8
• Exhaust manifolds: LHS (as viewed from sat in winch cab) 100027848. RHS 436002
• By 1976, the US emissions regulations were greatly limiting the power output of the V8s. Hence, the factory power output for this engine is quoted as being 185BHP.

Spare parts

• Oil filters are available from local parts factors (e.g Motorists Discount Centre, Newbury 01635 42015) But don't confuse the people by asking for a filter for an Olds 455 - simply ask for the filter by part number: Fram (the manufacturer's name) PH25 (the part number)(about £11) or alternative, Fram PH3429. (Other info I have suggests the following makes/model numbers of filters will work: AC PF45, Motorcraft FL-331, Purolator L20123)
• USautomotive (01234 273155). They're very helpful and have the parts in stock, or can get them quickly.
• American Autoparts (01737 780888) are also very helpful and have most parts in stock.
• Rodley Motors (01274 6968) very knowledgeable too.

Propane Gas Conversion

See the Propane Gas Conversion page for details