Late block / Early block

mgbv8 · Post by **mgbv8** » Mon Jan 22, 2007 9:21 pm

Hi
My old engine is a pre SD1 V8. If I get a later stiff block, will the front timing cover from the old engine fit and work ok?
Also, can I just swap over my cam and chain etc from the old engine?

Perry

ihatesissycars · Post by **ihatesissycars** » Mon Jan 22, 2007 9:22 pm

These are both 3.5 blocks?

mgbv8 · Post by **mgbv8** » Mon Jan 22, 2007 9:57 pm

No
The later block would be a 4.6.
I've looked at my books and the difference seems to be some extra ribbing on the front of the block which I thought were sealing faces at first.

Post by **katanaman** » Mon Jan 22, 2007 10:51 pm

You will need a spacer for the crank as the 4.6 (you are using a 4.6 crank aren't you? 3.5, 3.9 wont fit) crank is longer and the pulley wouldn't fit otherwise. I probably wouldn't recommend you use a pre sd1 cover though use an sd1 or landy cover for better oil pump and dizzy drive. Better still use the intermediate serps front cover

badger · Post by **badger** » Mon Jan 22, 2007 10:56 pm

Your timing cover will fit but I wouldn't advise it unless yours has been altered with the addition of a high capacity oil pump kit. Pre-SD1 pumps are waaay too small to provide enough flow for the larger crank bearings of a 4.6.
You'll also need a spacer to go on after your front pulley as the nose of the crank is slightly longer (10mm ish??).
As for using your old cam, it'll physically fit but most likely won't be a suitable profile for a 4.6 and also, if it's done any great mileage it will most likely be showing some wear.
What heads do you intend to use? pre-SD1 heads have smaller valves and will really strangle a 4.6, the later heads (all from SD1 onwards) have valves that aren't really large enough for the larger capacity as it is!
Badger.

ihatesissycars · Post by **ihatesissycars** » Tue Jan 23, 2007 2:26 pm

http://www.v8engines.com/engine-4.htm

If you scroll down the page in that link theres a fitting guide for fitting a 4.6 bottom end using earlier stuff.

Stevieturbo used a std 4.6 bottom end along with (i think) an sd1 front cover without problem and that had 500bhp with twin turbos so i'd imagine you'd be fine. I've read of a few people using earlier front covers on these without problem.

mgbv8 · Post by **mgbv8** » Tue Jan 23, 2007 9:12 pm

Thanks guys
I have fitted a hi flow pump kit already, and the cam is a Typhoon with pump down lifters that has done about 800 miles so nearly new. In fact, the whole engine has been rebuilt using all new stuff with a full balance 800 miles ago.
I was going to fit a crank damper to the old crank, but I would need to space the front pulley out about 10 or 12mm. Does this mean the slightly longer crank will do me a favour and hopefully make my pulley line up ok?

I have also already converted the old front cover to rubber oil seal.

mgbv8 · Post by **mgbv8** » Wed Jan 24, 2007 12:16 pm

The new block just arrived. The crank nose is 20mm longer than the old one. So what does the crank spacer look like, and where do I get one. I assume my old pulley wont reach the key fully.

Also, I bought some 4.6 heads last year. But on closer inspection, I see they have bigger ports, but the valves are the same size as my old 3500 heads?
I think I got tucked up there didnt I...

ihatesissycars · Post by **ihatesissycars** » Wed Jan 24, 2007 12:38 pm

http://cgi.ebay.co.uk/Range-Rover-Land- ... dZViewItem

The above kit has the spacer required and a disc to fill the dizzy hole. Rpi sell them so they may just sell you a spacer on its own if you phone them.

Basically, all heads from the 3.5 efi v8's onwards had the same size valves only difference is that some had wasted valves and some did not.

How many bolt holes do the heads you have have? 4.6 heads only have 10 bolt holes whereas anything else has 14.

seight · Post by **seight** » Wed Jan 24, 2007 12:46 pm

mgbv8 wrote:The new block just arrived. The crank nose is 20mm longer than the old one. So what does the crank spacer look like, and where do I get one. I assume my old pulley wont reach the key fully.

Also, I bought some 4.6 heads last year. But on closer inspection, I see they have bigger ports, but the valves are the same size as my old 3500 heads?
I think I got tucked up there didnt I...

Your pulley should reach the key but your crank nose will probably stick out of the pulley meaning the pulley bolt won't tighten up onto the pulley and the pulley will be able to slide out 20mm (or whatever it is).

Mike

mgbv8 · Post by **mgbv8** » Wed Jan 24, 2007 1:00 pm

Thanks Gav / Mike.
I'm getting geared up for the transplant now.
Will be back with more questions after the weekend no doubt.
Questions like, Where does this bit go !!!

mgbv8 · Post by **mgbv8** » Fri Jan 26, 2007 7:16 pm

I forgot to mention, its a cross bolted block. But it looks like my sump etc will swap over ok.