409 race engine

[Gary C]

Hi , I just bought a 409 short motor and heads.
The block numbers end in 656 and thinking this block is a truck block as calculated compression ratio comes out around 7.9 :1.
Is there anyway to measure across and down bore at valve relief to confirm it is in fact a truck block?

Thanks, Gary.

 

[BSL409]

With that compression it would be a truck block your should see that Relief cut out ? what heads are on it ?

 

[Gary C]

I thought they all had the relief but the truck block larger?

 

[63impalass409]

65 truck block with a nice looking pistons and aftermarket rods and main studs, those heads are the big port 690's

 

[Murphdog]

Your block pictured is a "truck" block, judging by the compression reliefs. But there were "car" blocks also without the reliefs. Or at least 1 that I have does not have them. Respectable looking parts there, judging by your pics.
Jeff

 

[Toms63SSQB]

Nothing wrong with a truck block, in somes cases maybe better than a car block.

 

[BSL409]

656 truck engine here some 350 passes over 9 years still running strong when i pulled

 

[Murphdog]

656 truck engine here some 350 passes over 9 years still running strong when i pulled View attachment 137289

I like the Sunnen/TA line boring machine!
Jeff

 

[Gary C]

Thanks for the replies, I want to get the CR up to 10:1 so new pistons are needed.
Also after roller cam , and rockers.
The block came with roller lifters.
Iam in Australia and not much 409 gear laying around here.

 

[Murphdog]

Thanks for the replies, I want to get the CR up to 10:1 so new pistons are needed.
Also after roller cam , and rockers.
The block came with roller lifters.
Iam in Australia and not much 409 gear laying around here.

Scorpion rockers seem to be the going thing. Probably have a distributor down there.
Roller cam, start hunting!
Jeff

 

[scott hall]

Gary those are not the low compression pistons. I'd check to see if they 0 deck or how much in or out of hole. Its cheaper to check than to replace and end up with same or real close to what you have now.

 

[Barry Taylor]

Is this a stock stroke motor!!

 

[Gary C]

The engine builder checking it over says the pistons are 30 thou down from deck and he measured 85cc in combustion chamber and 25cc in head with 3.5 inch stock stroke.
The engine was built by Norm Beechey himself as a spare hillclimb engine.
Norm used to circuit race a 62 impala in Australia and very well known , he is now 91 years old.
I didn't want to change anything he did but 7.9:1 probably won't cut the mustard circuit racing in my 64 Impala.

 

[427John]

You might take a close look at the pistons that are in it, if they have a fairly thick crown you may be able to run some BBC 6.135 rods and mill the pistons to zero deck them, that will bring the CR up some,I'd look into that before I sprung for new pistons.

 

[RussC]

Gary those are not the low compression pistons. I'd check to see if they 0 deck or how much in or out of hole. Its cheaper to check than to replace and end up with same or real close to what you have now.

Those are not low compression pistons

 

[MRHP]

25cc in the head seems HUGE! I think I would remeasure a bit.

 

[Skip FIx]

My E heads I think were only about 15cc in the head.

 

[La Hot Rods]

Can you show a picture of the valve side of the cylinder head?

 

[SSpev]

Those are some NICE looking pistons. 25 cc and 85cc??? yea 7.8.... I'd be re ccing those things. I would expect no more than 12cc on the heads stock. hopfully about 75 or less in cylinder.

 

[Jim Sullivan]

My 333 heads measured about 10cc after a light resurface. 348 double notch block measured about 75cc after a .030 deck cut with a cast 11.0:1 piston.