409 "crate engine"

[S Junkersfeld]

hello, I recently acquired a 409 replacement engine that has never been installed in a vehicle. Although I was sceptical, the 409 still has the paper tag pasted on the passenger valve cover, orange overspray on the exhaust manifolds and the original GM installation sheet attached - it appears to be legitimate. The engine is an XXG engine (truck replacement). Can someone tell me what the maximum attainable compression ratios are for these XXG engines? Can I get this engine up to 9.5 to 1 or so? I am working on a 1956 Chevrolet Cameo pickup project and will put a 409 with 6 Strombergs in the truck. Additionally, if there is any data that can be gathered from this virgin 409, I will be glad to provide it to anyone who might need it. Thanks Steve

[CDNpontiac409guy]

Steve, your truck engine compression ratio is an astonishingly low 7.75:1. This is created primarily through the use of a near flat top piston. Because your engine has perfect standard bores, you should be able to utilize a good used set of factory hi perf 11:1 forged pistons, which will be less than half the cost of new.
The final compression ratio ( using a composition head gasket ) will come in at approx 10.3:1. JUST RIGHT on pump premium ! A bit of cam, and you're in business :deal

[S Junkersfeld]

Aubrey,
Thanks much for the guidance. When my 56 Cameo is done, I have plans for a 409 in a 34 Ford Vicky. 7.75 to 1 might be a great ratio for a blower!

Thanks again
Steve

[jim_ss409]

Welcome to the site Steve! The truck engine has the same crank and rods as the hi perf car engine. I've always wondered if the truck pistons were forged or cast. Does anybody know? With the rising cost of hi perf heads blowers are starting to look like a reasonable way to go. That's the direction I think I'm going to go on my next project.

[Mr Goodwrench]

truck pistons are cast, I had three sets of them (still have some) but my highschool class has been melting them for projects.

[Fran Preve]

Good luck with the 6x2's. For a '56 Cameo, and given the engine your starting with do a cam and piston change, then open the intake up for a 625 Carter. Then put on a set of those cheapo chrome aftermarket valve covers. Here's the ticket, get yourself a 1963-4-5 Buick (or olds?) single four air cleaner, a NICE CLEAN one!, hard to find maybe (Hemmings?). This is a large, thin air cleaner about the same size as a 409 2x4 air cleaner (takes a 17" lid I think). Trust me. When I learn how to take a digital picture and post it I'll show you guys what they look like. Trying to make a 6x2 set up drivable is more fun than I'd like to try. Might LOOK cool ( not to ME!), but I'd rather have a smooth driving engine rather than a "wowser" looking carb set up.

[SSpev]

Fran, like this one. Why?? Tring to fake a 2-4?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=43946&item=7926153935&rd=1

[threeimpalas]

Trying to make a 6x2 set up drivable is more fun than I'd like to try. Might LOOK cool ( not to ME!), but I'd rather have a smooth driving engine rather than a "wowser" looking carb set up.

Most of the time "car show people" will set up their 6x2 setups to run off of just 2 or 4 of the carbs. Much easier to tune, still runs well, and looks "killer" to boot. A single carb is "blah" no matter what air cleaner is used.

[S Junkersfeld]

You hit the nail right on the head. A mild cam and the outside 4 Strombergs set up to work. I plug the fuel lines on the 2 middle carbs but connect all the linkage so the whole setup looks like it is operating. I have set these up on 2 other engines (not 409s) and they run extremely well. I think that the fuel flow spread out over the long runners makes for more even fuel distribution and they idle smooth as silk.

Steve

[BiscayneWilly]

Hello
This engine didn't happen to come from E-Bay did it Steve? Was a crate 409 truck engine, never installed. See attached pic..........I almost went for this engine but decided not to :doh

http://www.rcalloys.com/misc/crate409.jpg

[S Junkersfeld]

Bill, That's it. I thought the guy was blowing smoke, but everything on it looks to be right. Was there anything that turned you off about it that I should know?Steve

[BiscayneWilly]

Hi Steve
Nothing at all about the engine turned me away. Just at the time I had just begun my search for a 409. Didn't know much about truck engines since I never looked into them as an option. Did contact him asking for block, head and intake castings to figure out what it really was. All he told me was that it was a 409 crate motor that was never installed :) Should have tried to win the darn thing. Sounds like it really is a gem of a engine to work with. Neat that it came with papers and all that too! Good luck and that will make a dandy addition to your Cameo.

[S Junkersfeld]

Bill, I, actually have another 409 that I'm building for the Cameo. It's also a truck engine that I picked up in Minnesota. I'm thinking that since the compression ratio is so low on these truck engines and this one is bone stock and fresh, that I'll look at a blower for it and keep it for a street rod project that I'm planning. Steve

[BiscayneWilly]

Hee hee, blown 409.............what could be better :brow

[bobs409]

I know the factory got some overspray on bellhousings and perhaps exhaust manifolds but that doesn't look like a factory paint job to me. :eek:

Looks like someone did a respray during a small tornado. :D :p

This engine looks familiar, I think we talked about this one in another thread. ?

[Mr Goodwrench]

hmmmmm you say you block the fuel to all the inside carbs but hook the linkage up, when those carbs open without any fuel in them what prevents the engine from taking a big ol nose dive??? :dunno I believe you just dont undestand :help

[BiscayneWilly]

That was one of my thoughts too, paint job didn't look too factory. I know they did overspray onto exhaust manifolds but it looked a little much. Oh well, it has got to be a nice engine to have. Like I said, wish it would have ended up in my little hands :)

[dq409]

hmmmmm you say you block the fuel to all the inside carbs but hook the linkage up, when those carbs open without any fuel in them what prevents the engine from taking a big ol nose dive??? :dunno I believe you just dont undestand :help

I think you use a blocking plate under the carbs,,,,,dq

[S Junkersfeld]

The fuel is blocked just to keep from having 2 extra fuel sources (and potential leak sources). You always have to put a blocking plate between the carb base and manifold and remove the throttle plates to keep them from hitting the blocking plate.

[Mr Goodwrench]

ok I see now, just a little slow these days not enough coffee :doh