Help me carb or injection

[V8XR2]

Help me if you can I have a rover sdi v8 3500cc with a 4 barrle holly carb and stage 1 heads ( big end has gone ). I aslo have a tvr v8 350i 3500cc injection engine with 4 branch exaust manifolds. If I fit heads and exaust to tvr v8 will it make more power with holly or original fuel injection. Tvr is 200 hp standard I don't know power output of rover v8. Please help.

[kiwicar]

Hi Welcome
as usual its a depends, it depends on the age of the carb or the injection and exactly what ypu have, if the carb is less than 20k old and the injection more than about 80k then go for the carb, if the carb is more than 40k and the injection less than 60k then go for the injection, any other combination then it is a bit of a gray area. 4 barrel carbs are old by about 35 to 40k miles old and at least need a refurbish, more than about 60k the shafts are leaking so much they will not meter properly. Flapper injection which I am guessing you have is getting old by 90 to 100k but will need a refurb, this will leave you in a better state than a refurbed 40k 4 barrel but involves quite a bit of work (particulally wiring loom, senders and injectors). As for the rest, use the stage 1 heads, tubular manifold, and if the base engine has done more than 40-60k (depending on how often the oil was changed) change the cam, lifters and timing chain as they will be worn.
Best regards
Mike

[DaveEFI]

Help me if you can I have a rover sdi v8 3500cc with a 4 barrle holly carb and stage 1 heads ( big end has gone ). I aslo have a tvr v8 350i 3500cc injection engine with 4 branch exaust manifolds. If I fit heads and exaust to tvr v8 will it make more power with holly or original fuel injection. Tvr is 200 hp standard I don't know power output of rover v8. Please help.

The flapper injection when it is working correctly gives decent power, torque and economy. However, at 25 years old, it may well have some issues. There is a comprehensive guide to fault finding on Ramon Alban's site.

About the only component that does wear out with miles is the TPS - these are rare and expensive, but can be replaced with an aftermarket one and adaptor plate.
Since the EFI is analogue, all the sensors etc can be checked with a DVM and lots of patience. But it isn't adjustable other than for idle speed and mixture, so won't be happy with any engine mods, like a non standard cam.

The beauty of the EFI system is it forms the basis to fit a MegaSquirt.

[Ian Anderson]

Stick with the carb
Rebuild kit is not too pricy and it will look correct on the car

If you don't you'll have to change fuel pump to a high pressure unit and also plumb in return lines on the fuel sustem
There will also be additional loom cutting and joining required

All OK if you are keen on that stuff but..................

Keep it simple I say

Ian

[topcatcustom]

I think that a carb, especially a Holley will easily make as much power as injection (how many V8's do you see at santa pod with electronic injection), BUT it will be more thirsty and not as precise through the rev range.

To sum it up in a sentence!

Also as Ian says- if you like electrics and complicated stuff then fine, if not dont touch it! With a carb and dissy, if it has fuel and power, it runs, even if badly, if any single part of an injection system isnt working properly then you'll be lucky if it runs at all. Unfortunately we dont live in an ideal world.

That said I cant offend Dave any more- if you dont mind a lot of fiddling and know how to do a job properly then you will get good results with injection, it is after all the carb slayer but you have to know what you are doing with it!

[DaveEFI]

I think that a carb, especially a Holley will easily make as much power as injection (how many V8's do you see at santa pod with electronic injection), BUT it will be more thirsty and not as precise through the rev range.

To sum it up in a sentence!

Also as Ian says- if you like electrics and complicated stuff then fine, if not dont touch it! With a carb and dissy, if it has fuel and power, it runs, even if badly, if any single part of an injection system isnt working properly then you'll be lucky if it runs at all. Unfortunately we dont live in an ideal world.

That said I cant offend Dave any more- if you dont mind a lot of fiddling and know how to do a job properly then you will get good results with injection, it is after all the carb slayer but you have to know what you are doing with it!

It depends what you want the car for. If just posting good times at Santa Pod, carbs can give the same power as simple injection.
If you want a decent road car for all uses, injection is likely to be better.
TVR didn't change to injection just because of emissions.