which heads?

bak2burbles · Post by **bak2burbles** » Wed Aug 08, 2007 11:19 am

hi all.. budget rebuilding a v8 given to me, Its from an early 74 range rover, 8.25.1 cr, I'd like a little more oomph. Would sd1 heads provide any more bhp? currently off work (double spinal fusion op) so cash is tight
but time on my hands! Any info welcome thanks.

ian.stewart · Post by **ian.stewart** » Wed Aug 08, 2007 11:37 am

Have a look at this link,
http://www.v-8.org.uk/forum/viewtopic.php?t=1702
Ian

ChrisJC · Post by **ChrisJC** » Wed Aug 08, 2007 3:51 pm

Higher compression pistons would be a big help, and a better camshaft.

Not sure what heads that will have, but EFi heads are worth having.

Chris.

bak2burbles · Post by **bak2burbles** » Thu Aug 09, 2007 4:25 pm

thanks for info on pistons, heads etc...nice one.

bak2burbles · Post by **bak2burbles** » Fri Aug 10, 2007 9:37 am

ok.. efi heads sorted... As the old stromberg carbs i have are knackered with bits missing! & the I. manifold needs work (broken studs),Would i be better off spending the wifes bingo money on an efi set up? What are the power gains over standard carbs? & does the efi unit add any height to the engine? Its eventually going in a 2 door sierra, boring i know but i couldnt think of an easier rwd swap... many thanks ..

Post by **katanaman** » Fri Aug 10, 2007 9:52 am

EFI just fits in a Sierra so your ok there. As for power gains it depends on how well the carbs are set up. In reality there aren't any on an otherwise unchanged engine but what you get is a better spread of power especially lower down. Of course any gains are down to if the system is working properly or not as many of them aren't now.

ChrisJC · Post by **ChrisJC** » Fri Aug 10, 2007 11:39 am

With EFi, when it's sorted, it's great. But remember if you fit EFi, it's going to be 20 years old, so reliability issues might come up. If you understand how EFi works, then you'll be fine, but lots of people have trouble diagnosing and fixing problems with it, leading to frustration.

Of course if you build a completely new EFi, like megasquirt, or VEMs or Emerald or something, then you'll trade reliability issues for tuning up issues.

Chris.

bak2burbles · Post by **bak2burbles** » Fri Aug 10, 2007 1:46 pm

thanks...sounds like sticking to carbs might be the way for me, would have
gone efi if there was a good bhp gain but as i know nothing about efi maybe not.. good ol' su's then (?????), unless something else comes up cheap on e-bay!.
thanks for the info , nothing worse then not knowing.... hate the newbie tag btw, feel like a virgin all over again.. at 50? surely not...

Beastmaster · Post by **Beastmaster** » Fri Aug 10, 2007 5:03 pm

Im in the process of fitting a 3.9 efi into a sierra so if you need any help give me a shout..its easy

bak2burbles · Post by **bak2burbles** » Fri Aug 10, 2007 6:49 pm

cheers m8....noted ta.

bodger · Post by **bodger** » Sat Aug 18, 2007 10:27 am

ChrisJC wrote:Higher compression pistons would be a big help, and a better camshaft.

Not sure what heads that will have, but EFi heads are worth having.

Chris.

Hi Chris . are the heads differant than chris ?
i have not changed the heads on mine , i have just fitted the EFI in place of the carbs
and it's an old 8.13:1 engine

ChrisJC · Post by **ChrisJC** » Sat Aug 18, 2007 3:52 pm

On the EFi heads, there's a small cutout / notch in the roof of each inlet port to clear the spray pattern from the injector.

Obviously it doesn't make much difference!

Chris.

Post by **katanaman** » Sat Aug 18, 2007 6:03 pm

EFI heads should also have wasted stem valves helping it breath a little better.

bodger · Post by **bodger** » Wed Aug 22, 2007 2:54 pm

ChrisJC wrote:On the EFi heads, there's a small cutout / notch in the roof of each inlet port to clear the spray pattern from the injector.

Obviously it doesn't make much difference!

Chris.

mine has cutouts ??

ChrisJC · Post by **ChrisJC** » Wed Aug 22, 2007 3:47 pm

If it does, then they be EFi heads....

Chris.