Mediamab Posted December 18, 2023 Share Posted December 18, 2023 Hey! So I’m keen to check the setup on my v8 as I fear it’s running too lean, lots of popping with high revs etc. It appears from what I’ve read I can use the idle mixture screws and plug a vacuum gauge in to help determine the sweet spot. What I’m confused about, what is the key pressure I’m looking to achieve? is it simply the highest? Many thanks!! Quote Link to comment Share on other sites More sharing options...
Jon White Posted December 19, 2023 Share Posted December 19, 2023 The idle mixture screws will make bugger all difference if you have running problems at high revs. They only affect mixture at idle to about 1500rpm. What jets, metering rods and springs do you have in the carb? Are the floats set to the correct height? I’m running an SD1 V8 on an edelbrock 1404 with 0.86” primaries, 0.95” secondaries, 67-55 metering rods and orange springs. It seems about right. My mixture screws are about 2 turns out from fully bottomed. Mostly these end up running far too rich as they come jetted from the factory for a 5+litre engine. Jon Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 19, 2023 Author Share Posted December 19, 2023 Hi! Yeah a little tricky as the carb was fitted before I made purchase so I’m not sure exactly what the carb is fitted with. I’m mildly wary the engine feels quite sluggish, even compared to my stage 1 TD5. Would the carb setup be likely to cause this? How easy is it to see what it’s been setup with? Planning to upgrade the ignition system to see if that helps on performance with a kit from RPI. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 19, 2023 Share Posted December 19, 2023 Avoid RPI.... Standard ignition in good order is perfectly fine unless you like drowning your engine. Personally I would get a wideband lambda fitted, it is the only really reliable way to know what the engine is doing when driving about. 1 Quote Link to comment Share on other sites More sharing options...
Jon White Posted December 19, 2023 Share Posted December 19, 2023 22 minutes ago, Mediamab said: Hi! Yeah a little tricky as the carb was fitted before I made purchase so I’m not sure exactly what the carb is fitted with. I’m mildly wary the engine feels quite sluggish, even compared to my stage 1 TD5. Would the carb setup be likely to cause this? How easy is it to see what it’s been setup with? Planning to upgrade the ignition system to see if that helps on performance with a kit from RPI. Take the top off the carb and read the numbers off the parts. That’s the only way to know what youve got and you can check the float levels at the same time. Also check the timing and also check that the timing is advancing when the engine is revved. There is a plastic collar that can move and stop the advance weights from moving correctly. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 19, 2023 Share Posted December 19, 2023 1 hour ago, Mediamab said: Planning to upgrade the ignition system to see if that helps on performance with a kit from RPI. Don't do it! There's much better ways to spend that sort of money. I had this setup and honestly even the old flapper EFI setup worked better and didn't ice up in the cold or die on side-slopes. Also it's worth working out which V8 you've got, if it's an old low-compression 3.5 then swapping it for a later bigger lump is the most cost effective route to much better performance, buying upgrades for a low-comp lump is never going to give you much back. 1 Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 21, 2023 Author Share Posted December 21, 2023 On 12/19/2023 at 9:18 PM, FridgeFreezer said: Don't do it! There's much better ways to spend that sort of money. I had this setup and honestly even the old flapper EFI setup worked better and didn't ice up in the cold or die on side-slopes. Also it's worth working out which V8 you've got, if it's an old low-compression 3.5 then swapping it for a later bigger lump is the most cost effective route to much better performance, buying upgrades for a low-comp lump is never going to give you much back. Ah where / how do I find which engine I have? Afaik it is original from 1988. Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 21, 2023 Author Share Posted December 21, 2023 (edited) On 12/19/2023 at 8:24 PM, Jon White said: Take the top off the carb and read the numbers off the parts. That’s the only way to know what youve got and you can check the float levels at the same time. Also check the timing and also check that the timing is advancing when the engine is revved. There is a plastic collar that can move and stop the advance weights from moving correctly. With regards to timing I’d read to aim for 6degrees off TDC for idle, would that be a good starting point? When you say advancing, should that gap become greater then? Also what are the advance weights? Also with float levels, am I looking at a set measurement for my v8? sorry for all the possibly dumb questions, just trying to learn as much as I can Edited December 21, 2023 by Mediamab Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 21, 2023 Share Posted December 21, 2023 1 hour ago, Mediamab said: Ah where / how do I find which engine I have? Afaik it is original from 1988. Engine number tells you, there's a few lists online like this: http://v8forum.co.uk/RoverV8FactoryEngineNumbers.htm Float levels will be whatever the setup guide for that carb says, there's bound to be a ton of stuff on US websites about that as they seem to enjoy all that clockwork nonsense. 1 1 Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 21, 2023 Author Share Posted December 21, 2023 11 minutes ago, FridgeFreezer said: Engine number tells you, there's a few lists online like this: http://v8forum.co.uk/RoverV8FactoryEngineNumbers.htm Float levels will be whatever the setup guide for that carb says, there's bound to be a ton of stuff on US websites about that as they seem to enjoy all that clockwork nonsense. Ah ok great. Well I guess if it is original which I believe it is then likely to be 8.13:1 which I assume is low compression? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 21, 2023 Share Posted December 21, 2023 Yup, pretty low, 135bhp tops really, with your setup. Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 21, 2023 Author Share Posted December 21, 2023 Ah I see ok. Some days I’m wary I’m even getting that tho ha but hard to tell properly ey. There is a slight tapping noise when engines warm - I’ll attach a video that should show it.. just wandering if that could be an issue with warn tappets? Or if it’s just a normal tap noise ha. Challenge is I’ve always had Td5s so trying to adjust to V8 and understand what’s standard! IMG_0307.mov Quote Link to comment Share on other sites More sharing options...
Jon White Posted December 21, 2023 Share Posted December 21, 2023 Download the manual for the carb from edelbrocks website. That will tell you all you need to know. CR is often stamped on the block adjacent to the engine number. 1 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 22, 2023 Share Posted December 22, 2023 As we thought then - the cost of tuning that much more than it already is is likely more than throwing a bigger lump in there. Fitting the later EFI camshaft can gain you a little (if you're in there doing tappets, for example) but with the low-comp motor you'll always be starting at a disadvantage. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 22, 2023 Share Posted December 22, 2023 If it's any consolation, the engine doesn't sound unhealthy, but always hard to hear everything on a phone recorded video. 1 Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 22, 2023 Author Share Posted December 22, 2023 I did think it sounded pretty healthy? It’s just the slight tapping I wasn’t sure of. Read it can be the tappets or even the manifold? to be honest I’m ok with the solid performance this engine can have, just keen to ensure I’m getting the most out of it for now. Maybe a 4.6 could go in in the future tho! Have been debating changing the cam shaft but really need to do the work myself. Is it a huge undertaking or following the workshop manual and some common sense is it relatively achievable? Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 22, 2023 Author Share Posted December 22, 2023 Also is there any value in getting one of the 123/tune+ distributors? Came across them last night and appear to get some good reviews or just overkill? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 22, 2023 Share Posted December 22, 2023 Cam is common sense and workshop manual, plus the break in procedure, you do need to remove the radiator and all the front accessories, and inlet to do it, but doable in a day if experienced. Biggest fight may be seized bolts, particularly the water pump, but it is all soluble. 1 Quote Link to comment Share on other sites More sharing options...
landroversforever Posted December 22, 2023 Share Posted December 22, 2023 I'd save the cash and keep it towards a future Megasquirt installation. 2 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 22, 2023 Share Posted December 22, 2023 26 minutes ago, landroversforever said: I'd save the cash and keep it towards a future Megasquirt installation. Agreed - you can use it to run ignition-only too, so no need to swap the carb if you don't want to. I would though You can improve on the factory ignition amplifier with a few different OEM ignition amplifiers, the V8 Capri forum I think had a write-up many moons ago about using a GM (Vauxhall) part that was more reliable and would run a more powerful coil, I had one on my RRC but that was a long time ago. Quote Link to comment Share on other sites More sharing options...
Mediamab Posted December 22, 2023 Author Share Posted December 22, 2023 Yeah I think for now I’ll keep setup and then maybe do a whole engine upgrade and keep costs for now sensibly low haha ill have a hunt for a good amplifier though, I feel my coils seen better days too but it may just be the wiring as think I have a few wiring issues. Found a wire laying directly on the top of the exhaust box yesterday which wasn’t loving it 😅 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 22, 2023 Share Posted December 22, 2023 2 hours ago, Mediamab said: Yeah I think for now I’ll keep setup and then maybe do a whole engine upgrade and keep costs for now sensibly low haha Worth keeping an eye out for running-but-rusty D2 or P38's with the 4.0 or 4.6 going cheap, always nice to drive it before you swap it. Quote Link to comment Share on other sites More sharing options...
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