340 heads on a 350

[Jim Blackwood]

Randy, this is a real find!

We've been kicking around the idea for several years now but so far you are the first with the parts actually assembled. If it did run, I'd guess it has a custom ground cam in it. If you can see the rear cam bearing, an oversize bearing to allow use of the 340 cam should be fairly obvious as it should be around 1/8" thick. But based on information from direct measurements, the center cam lobes should then be off enough to cause trouble. If you have it together enough to do it, rotate the crank and see if the valves open in the correct sequence. You are particularly looking to see if the center four valves are reversed. Check out this link, particularly page 4:
http://www.v8buick.com/showthread.ph...eads+350+block

From your observations it could be that pushrod misalignment is less of an issue than we've been led to believe based on measurements taken, and this would be a tremendous benefit. So it is crucial to this effort to find out just how well the parts fit together. If you could post some photos that would be most helpful. If it turns out that the pushrod geometry really is that close, then all that would be needed to run the new TA heads on a 350 block is a custom cam. Not at all an insurmountable obstacle.

Jim

[Jim Blackwood]

Also, if you get the chance, I'm guessing from your comments that the engine has a custom ground cam in it. That is based on your description of the lobes being well centered in the lifter bores. If that is the case and the valve sequencing is correct then it would be of tremendous benefit to learn the source of this cam. There may be some markings on the nose of the cam that can be used to help identify it. That is actually the last remaining piece of the puzzle that needs to be resolved, and if known might enable the building of high performance 350's in the neighborhood of 400 lbs of weight. Obviously this has potential.

Jim

[turbos1w]

Hey guys, I'm interested in a couple things your talking about but 1st, why we want to do this swap? Whats the real benefit? Are the runners bigger, smaller, do they have a smaller cc or larger cc combustion chamber? Inquiering minds want to know.

[bob k. mando]

why we want to do this swap? Whats the real benefit?

the single largest benefit is actually slightly in the future. www.TAPerformance.com has 215/300/340/Rover aluminum heads in prototype at a casting plant. they're hoping to be in production by next year.

if we can use this style of heads this would be the very first aluminum head to ever be available for a Buick 350.

other benefits would be:
availability of existing Rover style parts to use ( headers, intakes, valve covers, etc )
modern combustion chamber design
much better than factory runners, straight out of the box ( TA big block heads normally flow as good or better than heavily ported factory irons )
big weight savings over the factory head+intake combo



Are the runners bigger, smaller, do they have a smaller cc or larger cc combustion chamber?

i think as far as the factory iron castings go, there's probably only one advantage to a 340 head.

a Rover style head separates all of the exhaust ports so you don't have a hot spot in the center of the head like you do with a SBB 350 or BBB. this doesn't mean much for street use but it makes a difference for all out race applications.

Buick/Rover engines other than the 340 don't have the runner size to support a 350 displacement.

[Jim Blackwood]

why we want to do this swap? Whats the real benefit?

Buick/Rover engines other than the 340 don't have the runner size to support a 350 displacement.

Unless you add a blower.

The weight reduction is a big deal too, getting the weight of the engine down to around 400lbs or less for 350 cu.in. with an iron block makes a big difference in many applications. Also cheap aluminum valve covers are available. Those things may not mean much for restoration type applications, but for others it can make or break the build.

Jim

[turbos1w]

So let me get this straight, The Rover is a 340 or it just uses the 340 base line parts? So tell me this, I have a 66 Skylark w/340 4bbl, are there parts from a rover that will work?

[Jim Blackwood]

Aw heck no, the Rover was a 215. It's grown up to about 4.6 liters but that's still smaller than a 300. It *is* aluminum which is pretty cool, and fits in a lot of cars, but stepping up to a 300 or 340 with aluminum heads and intake is very much worth the roughly 80 lb weight penalty.

What Rover parts fit your 340? Well, valve covers for one, there's a front cover with a concentric oil pump that might be made to work, cams, rocker shafts, the P76 intake with about 1/4" spacers but you might not like the runners, Wildcat heads$$$, the new TA heads, and ancillaries. Not a great source for spare parts but one to keep in mind.

Jim

[bob k. mando]

So let me get this straight, The Rover is a 340 or it just uses the 340 base line parts?

no, as Jim says, a Rover v8 is not a 340. is what it is, is in the Small Block Buick family. the original SBB v8 was the aluminum 215ci, in production from 1961-63. in 64, GM transitioned to the cast iron, taller deck 300ci and sold the designs and molds for the aluminum engine to British Leyland/Land Rover in 1965. BL / Land Rover referred to it by it's metric displacement of 3.5L

so the 215 ( short deck ), 300 ( mid deck ), 340 ( tall deck ) and Rover engines ( short to mid deck ) can all swap many parts.

the Buick 350 is still in the SBB v8 family, but when they introduced it in 1968 they changed the valve order around so that the center exhaust runners on each side were siamesed together just like a SBC. makes for cheaper casting and assembly on the exh manifolds. if you look at your heads, you'll see four discrete exhaust runners on each side. a 350 only has "three" runners.

in order to keep from people getting confused and installing the wrong parts, Buick made several other changes like making all of the cam bearings the same diameter ( so it's impossible to install an earlier cam in a 350 or vice versa ) and changing the valve cover design.

your 340 has the same crankshaft as the 350, it just has a slightly smaller bore. there's no real advantage to you in "upgrading" to a Buick 350 block as you'd only gain 2.94% displacement.




the P76 intake

just so you know, the "P76" is an Australian only variation of the Rover design that displaces 4.4L but it had a taller deck and longer rods than any other Rover variant.
http://en.wikipedia.org/wiki/Rover_V8#4.4



It's grown up to about 4.6 liters but that's still smaller than a 300.

actually, TVR punched it out to 5.0L in the Griffith 500 and Chimaera. at 305ci, it's slightly larger than a 300. still a shorter deck than the 300, 340, 350 and P76 though.
http://www.carfolio.com/specificatio...car/?car=30481



Unless you add a blower.

tch, tch, tch, Jim.

you know that most people on the 350 end of this are not dealing with your type of under weight, over powered, traction limited cars. runner size and intake charge heating will be a concern for most of us here in the States.

[Jim Blackwood]

runner size and intake charge heating will be a concern for most of us here in the States.

Hmmm.... building an experimental intercooler for that.
My target is 300hp, a fairly modest goal for a 340 I think. That'll give me 1 hp per 8 lbs of vehicle weight which should be plenty.

Jim

[turbos1w]

Turbo's are simple enough, 300hp should be a walk in the park on motor alone. Are these motors that weak? If your stock 340 only makes 150hp on motor you can ad 14psi and basicly double you numbers.