Crossflow Woes/help

[Mike Bentley]

Hi guys and Girls

Here goes.
I bought this engine a 1600 681F with unknown history it had been standing for 2 years and started straight away without a single Knock or rattle
I opened it up and found it to be bored out to +090 with no bore ridge and still nice honing marks, plus the shells are almost like new.
At first I thought happy days but +090 on a 681!! on further inspection it has a chambered head but "711m" pistons. (Low Compression??)

I was hoping to fit a worked chambered very big valves (valve size 42 & 36approx) and ported head I bought at a good price years back ( After measuring and comparing chamber sizes) along with a BCF2 cam and twin 40s.
But I think the comp ratio will be to LOW.
I have a 1300 engine in the shed (Which should have a flat head on it) so could just fit that.

QUESTIONS
1. IS IT WORTH FITTING THE BCF2 CAM WITH THE STANDARD 1300 HEAD.
2. OR WILL THE FACT THAT A LOT OF GASES WILL BE GOING IN AND OUT OF THE RACE HEAD WITH CAM AND CARBS THAT THE LOWER COMPRESION WONT MATTER MUCH.
I KNOW I AM PROBABLY DREAMING

[racing escort]

You can skim the head with chambers to raise compression, the 1300 will need work to outp ierform the big valve head.
The BCF2 cam is fast road and doesn't need high compression.
Are the pistons flush with the block ?

[oldskoolrools]

the head in the picture will definitely not work with the pistons you show. that head needs flat top pistons and some compression ratio calculations.

you would be better with the 1300 head with the bcf2, but even better would be to find a nice 1600gt head, give the ports a tickle and away you go for pennies.

[oldskoolrools]

the head in the picture will definitely not work with the pistons you show. that head needs flat top pistons and some compression ratio calculations.

you would be better with the 1300 head with the bcf2, but even better would be to find a nice 1600gt head, give the ports a tickle and away you go for pennies.

[Forest_rallying]

I would be very interested to find what the cc is for the chambered head shown in the photo. It's quite possible that the cylinder head shown should run with near flat top pistons. It was a modification used on early Hot Rod engines in the 70's.

You need to work out your compression ratio, it's quite possible that you could have as little as 8.00.1 with that combination. From memory LC X Flow heads had a very shallow chamber to use with bowl type pistons, the one shown seems to be much deeper.

[Mike Bentley]

thanks guys I thought maybe 8:1 would be about right, I have the Perspex etc to measure the chambered head at some point in order to sell it as I just bought this baby on flee-bay for £93.00
with some nice porting

[Mike Bentley]

pistons roughly 0.8 to 0.9 mm down