Jump to content

Bumping compression spark plugs and timing


HighLUX

Recommended Posts

Iv just got my Gen 2 3s-ge running again but I cant seem to get it running with right, it runs and idles fine but when I take it for a blast down the road it doesn't have that "oomph" it used to.

Its had the head skimmed at least 3 times so the compression has been bumped a bit.

Factory engine manual recommend BKR6E 0.8mm plugs and 10 degrees BTDC at idle for timing, its running 8mm plugs and runs better with the timing set @ 14ish BTDC.

Should I change to a different gap and heat range plug?

It runs on 95 since theres no BP with 98 nearby

How can I tell where timing should be set?

Link to comment
Share on other sites

have you tried bigger gap on spark plugs?? might be the issue as 8mm is normally the gap you'd run on a turbo engine, around 10-11mm is more like a NA high comp gap. ask 1ovakind about spark plug gaps lol

imo would be worth a try considering its only $20 worth of plugs.

Link to comment
Share on other sites

Try retarding the timing a little - you might find with 3 head skims and advancing the timing to 14 degrees that it may be detonating its tits off and the computer is savagely retarding the timing to compensate. Bit pie in the sky theory but it may work.

Hang on - 8mm gap??? 0.8mm I think you mean - like Rhys says - you could try opening up the gap to 1.0 or 1.1mm

Link to comment
Share on other sites

Wouldnt 14 degrees BTDC be retarding the timing or am I missing something? I have dropped the timing back to the stopper then advanced just a touch is where it seems to be running best. The plugs were 1.1mm but it made no difference so I gapped them down to 0.8mm

Link to comment
Share on other sites

nope - 14 degrees BTDC is more advance than 10 degrees BTDC. If you wanted to retard the timing you would go numerically lower..

(if it was ATDC then yes higher numerically is retarding it but I am yet to find a car that runs with the timing set anywhere in the ATDC range)

Also bigger gap = more resistance and therefore a more potent spark. (with the risk that it is susceptible to being blown out - that is normally only a problem on forced induction cars though)

Link to comment
Share on other sites

Ah I see how I stuffed that up, just had a play and the timing is fully retarded(wouldnt know what its set @ though as my timing light just f**ked out) gapped the plugs to 1.1mm and swapped out one with cracked porcelain.

Its running perfect again!

Thanks K-trips for the your the best

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...