Twin SU plumbing and throttle

Tonycougar · Post by **Tonycougar** » Sat Nov 30, 2013 7:38 pm

Spoke with Jim from JRV8 today in Ireland. What a helpful bloke freely gave me loads of advice about V8s. Basically he said the same need to connect up the crankcase breather system properly.
He can supply the parts too (which I have discovered are quite hard to find). Highly recommended.

bigaldart · Post by **bigaldart** » Sun Dec 01, 2013 2:33 am

Jim is a great bloke and knows his Rovers, you can't go wrong there.

Alan

Tonycougar · Post by **Tonycougar** » Mon Dec 09, 2013 10:49 pm

Ok, so conected up the pipes like Jim and others suggested.
Run to normal temp.
Still ticking over too fast,
So.....I slow it down with the now effective idle screw. then it tries to die......... eventually. So take it up a millimeter turn or so and go for a run. Get home and its revving its head off again. So I sat there on the engine turning each SU down mm by mm and trying again each time its either too slow that it wants to die or it revs its head off.
Jim did say I might need to adjust the mixture but I wasn't sure which screw to turn and then I ran out of time/daylight.
Messing with the mixture and other settings in my previous (80's) experience always cocks it up unless you:-
A. Know what you are doing (I don't)
B. Have the tools (Again I don't)
So me thinks I need a V8 specialist near me?

kiwicar · Post by **kiwicar** » Tue Dec 10, 2013 8:51 am

Hi
I am pretty sure you have over run poppet valves in the throttle plates on that version of the SU, lift the piston and have a look, if they are there then remove the carbs and solder them shut, you certainly have the symptoms of poppet valve spring failure! I have done a couple of recent posts on poppet valves so have a hunt. Once you are certain you have sorted this issue then set the idle on the idle screws, with the cross linkage disconnected and the throttle cable removed, once it is stable and correct re attach the linkage and throttle cable checking all the time that you are not effecting the idle and that when you operate the throttle the pistons rise together. now set up the mixture as per the Hains manual, any Hains manual for any rover/layland car with 2 SUs will have the procedure, but the one for late model V8 range rover would be best in your case.
Best regards
Mike

Tonycougar · Post by **Tonycougar** » Tue Dec 10, 2013 1:23 pm

Thanks Mike.
I'm sure it does have the poppet valves. Think I saw them when I looked in there. Saw a post somewhere on here (was probably yourself) suggesting to solder them shut, and I was wondering whether to do that.
Can it be done with the carb on the car?

kiwicar · Post by **kiwicar** » Tue Dec 10, 2013 3:50 pm

Hi
no you have to take the carb off the car. . . you also need to get the petrol out of the float bowles or take the throttle plates off the carbs before you start soldering especially if you use a blow torch

best regards
Mike

Tonycougar · Post by **Tonycougar** » Tue Dec 10, 2013 9:48 pm

Not a quick job then?
Wondering if I should just put up with it for the time being.

kiwicar · Post by **kiwicar** » Wed Dec 11, 2013 7:54 am

Hi
not that long, 5 minutes to take the air filters off, 10 minutes to clean things up before stripping off the manifold, 10 min to get the linkage off and 10 for the 4 nuts each side holding the carbs on. . . 15 minutes each carb to take the bottoms off the float bowl each side and wash them out with warm water and you are ready to go, 5 min to solder them shut and about 30 min each to put them back together and back on the engine what 2 1/2 hours 3 with a stop for a cup of tea half way through for the whole job.
While they are in your hands you can save time on later set up and tune by setting the jets to the starting position and setting the idle position of the throttle plates the same on each carb with a feeler gauge, much quicker with the carb in your hand.
best regards
Mike

DaveEFI · Post by **DaveEFI** » Wed Dec 11, 2013 10:11 am

When I had the same problem with my P6 3500s, I just replaced the butterflies with plain ones.

kiwicar · Post by **kiwicar** » Wed Dec 11, 2013 7:03 pm

Hi
I must confess the first thing I did when I installed the boxer manifold on my first range rover was to convert all 4 SUs to plain throttle plates. However I was trying to get this chap a solution that did not involve any more dismantling and setting up than necessary, and centering SU throttle plates can be a fiddle, as can putting the fixing screws back in the throttle shafts!

Best regards
Mike

Tonycougar · Post by **Tonycougar** » Wed Jan 08, 2014 2:09 am

Did some more tinkering, topped up the dashpots, checked the poppet valves were not stuck and stuck a bit of lube on them. Shoved some redex in the fuel and then just sat there in the engine bay tweeking it bit by bit. Now it seems to have settled down, and burbles quite nicely.
Thanks for all the advice.

Fed_up_Stag-owner · Post by **Fed_up_Stag-owner** » Tue Feb 07, 2017 6:03 pm

Pocket rocket wrote:Hope these pictures help (engine as it came to me)

9 years later .... I'm looking for a choke linkage as shown in the image above, any suggestions for suppliers and/or part numbers would be appreciated.

RV8 now in the engine bay of my Stag.

Fed_up_Stag-owner · Post by **Fed_up_Stag-owner** » Wed Feb 08, 2017 4:07 pm

This is probably ERC1161.