V8 specs - anyone got them handy?

rockdemon said:
Mine are heads from a vitesse I believe...

Rich
Click to expand...

It's possible that the Vitesse had a groove machined around the top of the valve guide to accept proper seals, but it's also possible that I may have dreamt that following years of trying to forget all about SD1's......... (ISTR the Vitesse valve guides were waisted at the bottom as well. (Oh dear, what has this started, it's all coming back to me...Take me back to my padded cell please...)
 
Thanks guys. THink this may be the best thing for me to try... Afterall it runs very sweetly now otherwise!

Rich
 
If you decide to replace the cam always replace together with the lifters; ie.don't run a new cam with old lifters or an old cam with new lifters ( ! ) Although it's an "engine out" job; replacing the cam bearings, which any competent machine shop can do, is advisable as these are invariably worn beyond tolerance in older engines Curiously, Rover never offered these as a spare part, but http://www.aluminumv8.com in the States has 'em +I think I paid about 60 bucks a set... Other Rover specialists will have these too

part number: AEC 5088 on AllyV8's site

Good luck with your mods ( ! )

GW
 
Thanks. Really appreciate the Advice.

Sorry Harvey to have caused a reccurence of your sd1 nightmare.... They never existed really.... ;)
 
harveyp6 wrote,...
ISTR the Vitesse valve guides were waisted at the bottom as well.
Click to expand...

It's actually the inlet valves which have waisted stems, not the guides. Vitesse waisted stem inlet valves were to become standard fitment on all Rover V8 cylinder heads from late 1989 onwards.

Ron.
 
It's actually the inlet valves which have waisted stems, not the guides
Click to expand...

Vitesse SD1 valve guides are "bulleted" + to get them out of the way of the gas-flow, if you've got the Vitesse heads, Rich, the guides will look like the short ones in the top row of my picture, the bottom ones are yer stock SD1 items

GW

Picture200941.jpg
 
There are more differences than i realised. They were put on out of necessity not for any performance increase so I'm happy about that.(I knew it could help a little but didnt know the hows whys and wherefores etc...)

I'm going to monitor a little then make decision what to do. It went for a 25 mile run last night and seemed absolutely fine. This is the first lot of oil it's had since it's layup currently so it's possible it just had flushed out crud inside the engine i guess?

Rich.
 
So much knowledge on this forum! It's a goldmine.

Does anyone know the cfm of the twin SU setup? This is one of the few bits of info I can't find.
I've been plugging all the info I have into Desktop Dyno.
 
Hi Geoff,

Each HS6 carburettor will pull a maximum of 210 cfm, while each HIF6 will see an increase to 240 cfm. The manifold that accompanies the latter is also improved, so for best performance that is the combination to go for.

Ron.
 
Hmmmm

My manifold has HIF6 stamped on it but when I got the carbs rebuilt, I'm sure the guy wrote "HS6" on them.

:?

is there a way to identify them. I remember that the tags on my SU's indicated they were for the Japanese Domestic Market.
 
I had a squizz at the photos of your carbs Geoff and as expected they are HIF6. Doesn't say a lot about the fellow who rebuilt them if he thinks that they are HS6's... :roll:

HIF stands for Horizontal Intergrated Float, where the whole carburettor effectively lies in the same plane. HS carburettors have a seperate float chamber which sits out the front of the section housing the butterfly, piston and dashpot. Hence the designation...Horizontal Side (HS) bowl.

Ron.
 
Cool, thanks Ron.

So, I've plugged all the data into Dyno2000 aka Desktop Dyno and these are the figures that came out:

Induction flow: 480cfm (ie two HIF SUs) @ 3.00inHg with a dual plane manifold
Cam Specs: I put in seat to seat timing.

Intake duration: 285
Ex duration: 285
valve overlap: 67
Lobe centre: 109
Valve lift (in and ex): .39

Normal timing I put in 6.0

IVO BTDC: 30
EVO BBDC: 68

results: 175HP @ the flywheel at 5,500 to 6,000. 182 pounds of torque at 4,500.

I'll start playing around with some other figures now, I also have to work out how to add in things like pushrod length/lift etc.
 
Just in case you missed it; this reco'd 3.9 was for sale in Sydney; looked fairly "plug and play" for a P6B

http://www.classicroverforum.com/viewtopic.php?f=33&t=10379&p=78741#p78741

A quick dash down the Hume ( ! ) :wink:

BTW; I've used Desktop Dyno + while it's fun + I don't doubt their claim of "accurate to within 5%" holds; Dynomation 5 has even more variables to tweak + is the latest update to that software No idea *why* you would want to change the pushrod length; lift is already accounted for by the cam lobes and the only other variable is the rocker arm ratio; 1.55:1 is stock for Rover V8s and 1.6:1 is available if you use aftermarket alloy rocker arms ( Harland + Sharp/Crane/ YellaTerra ) and lastly your head gasket thickness Standard valve lift is 0.39" ( 9.9mm ) but an aftermarket cam that lifts up to 0.43" ( 10.9mm ) is possible, beyond which coil-bind on the Rover single valve-springs becomes an issue The software doesn't actually "see" this situation tho' + will let you dial in unattainable valve lift heights to your hearts content ( ! ) Suffice to say with the limitations of the stock setup stock pushrods are your default option

Higher cam lifts than 0.43" are achieved using adjustable rocker pedestals and different valves/valve springs ( or Merlin heads ) but that's getting esoteric + megabuck + it's only then you would be messing with different pushrods than stock ( or when fitting a roller cam )

Lots of discussion over at British V8.org, this TR8 owner got within 2 hp of Dynomations projection once he'd built + dyno'd his engine

http://forum.britishv8.org/read.php?6,16387

GW
 
Pushrod length was for one of the triumph guys at work, as you point out though Ron, thats covered by the cam lobes but it's something we were chatting away about in the lunchroom.

I didn't see guy's engine for sale either. decisions decisions, to pull one out of a wreckers that's popped up near me or get that one. hmmmm
 
Not "Ron" but I'll accept your kind thanks anyway + want to take the opportunity to thank the Academy, my agent and my parents for always.... Oops.wrong forum ( ! ) :oops:

GW
 
GW - what timing value do you use in Desktop Dyno? I put 6.0 in as that's all I could find online?

I also put in cam specs @ "seat to seat", is that right?

with .39in of lift for the exhaust and inlet valves it gave the cam
lobe centre: 109
valve overlap: 67.0
inlet duration: 285
exh: duration: 285
 
I have put a hi lift cam in my p6 auto but i cant seem to get it to run right it either ticks over right but then when you put it in gear it cuts out or you have it ticking over fast then its all right i set the timing at 6 can any one help
 
Hi - welcome to the forum!

I suppose the first question is which sort of cam exactly have you installed, and have you also changed carb needles? Anything else different from standard?

WOuld love to see some pics of your car :)

Rich
 
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