1988 3.5 V8 spark plugs.

M

Murray1967

New Member
I know this will be a question asked a million times. Had my v8 7 years and now have decided to change the plugs. What is the prefference?

Thanks for patience and understanding.
 
I had Champions in mine for years. [Ive got electronic ign].
Mind fart and changed to NGK.
Blaarck.
Couldnt get her to run well.
Luckily I didnt throw the Champs too far.
Back to nice now.
 
GRTV8 said:
I had Champions in mine for years. [Ive got electronic ign].
Mind fart and changed to NGK.
Blaarck.
Couldnt get her to run well.
Luckily I didnt throw the Champs too far.
Back to nice now.
Click to expand...

That is odd. Champion have a very iffy reputation over here. I have always got on well with NGK. As for the OP -
Of course it pays to pull one out and see if they are short or long reach. As for heat range I have always gone for 6 's and have not had any fouling issues.

Who pays attention to this - tightening torque ?
Torque is important as too loose and the plug can over heat / pop out, and too tight and you can strip threads / shear off the plug.

For aluminium heads NGK recommend 18 - 21 lb ft

But if you use anti seize compound on the thread, use sparingly and reduce torque by 30 %.
 
Ok so long or short. What is the difference on the engine. Also. How do identify the engine type. Is there a chance of a long one hitting a piston.
 
Murray1967 said:
Ok so long or short. What is the difference on the engine. Also. How do identify the engine type. Is there a chance of a long one hitting a piston.
Click to expand...

If your engine number is stamped on the top of the left hand block face viewed in between the centre exhaust branches then you will have an SD1 engine.
If the engine number is stamped on the rear of the block, left hand side, on the bell housing flange, you have a pre SD1 engine. Assuming no one has changed the heads then SD1 = long plugs.
Putting long plugs in place of short will not cause them to hit the pistons, but after a time as coke builds up on the longer exposed threads inside the combustion chamber you will have difficulty getting them out.
With a plug out using a sharp focused torch beam it should be possible to see how deep the thread is in the head. Casting marks identify heads, but they are under the rocker covers ( which might also have been changed from one type to another )

There is loads of info on the internet about the differences in Rover V8 engines.
 
Many thanks. I will remove a plug. Measure it and also .measure the threads in the head. Now u understand the issues i can move ahead.
Many thanks to everyone.
 
It might help if you (OP) clarify which make/model.

Looking at the screenshot, it days TVR. Is that correct, if so, which one? There was a supercharged 350 available around that time, possibly using different plugs from the standard vitesse-engined 350. They also did a 390 and possibly the 400SE at that time, although they weren't 3.5.
 
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tonys said:
It might help if you (OP) clarify which make/model.

Looking at the screenshot, it days TVR. Is that correct, if so, which one? There was a supercharged 350 available around that time, possibly using different plugs from the standard vitesse-engined 350. They also did a 390 and possibly the 400SE at that time, although they weren't 3.5.
Click to expand...

Hi, In post#14 he says it's a crate engine.

Colin
 
Hi guys. Its a 150hp crate motor. 3.5. Standard of the day. The original factory v8 was the same engine but 125hp. They kept the hp low as i meant not having to change mych else frim the standard 1.8 MGB. Money saving at the time. I think the original plan was for about 200hp which are easy numbers to reach. But that means new brakes, hearbox, back end etc. Which of course would drive up the cost. I will take a look at one of the plugs that i remove. Measure the head threads and take it from there. My biggest concern was that if installing a long reach plug in a.short reach head that it may have touched the piston. Apparently this cant happen.
 
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