what about indexing the plugs? You guys do anything along those lines?
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I have been doing this for as long as I have had toyota engines. With the 1fz i do not want the ground straps back (closed side) pointing toward the intake valves. Just about any other place is fine, but I usually perfer the open gap to point either towards the front or back of the engine. Jsut my 2cents. As to why? less chance for the ground to interfer with the the spark meeting the flame front before it ingintes. later robbie
thanks guys!
A last question. I've lowered the static compression ratio on my engine. Any thoughts on how that plays into the ideal heat range and gaping of the plugs?
I know this is really outside the norm of our experience with the 1FZ-FE but I haven't been able to find much on the web about this.
As a very vague generality if the compression ratio is really dramatically lowered from the stock setup, it would indicate a little less need to decrease gap down but I don't think that the amount we're talking about through your piston planing would make much matter. This isn't anywhere near as well documented as decreasing gap down for increasing power though and there is lots of lingering debate so I'd say to stick to recommendations regarding increasing power vs. decreasing compression. Hope that helps.![]()
After I posted I thought about it some more and tried to math the change I made and it does seem to be rather small. I was actually coming back here to delete the question.
Yes, the OEM MR2 turbo plug is a 6 heat range.
As far as the plug gap, a lot of that will depend on the amount of boost you're running and what ignition box & coil you're running.
I ended up making my call for what plugs I'll try first. I basically took everyone's advice and with a lot of research came up with what I hope is a good plug
Denso PK22P8, it's a range 7 plug, double platinum and similar to the ones in the MR2 so it should be gap-able. The factory gap is .8mm.
Shaun, everything that I've read on both the Denso and NGK sites list the factory stock plug to be an ISO and not a JIS. That extra 2.5mm in height concerned me about the plug wires sealing to the valve cover properly. But that could have been worrying for nothing.
Thanks for you help guys![]()
Again both the Nippon Denso and the NGK plugs were originally JIS. In fact I think the ND is still JIS (I haven't checked that though) I know for a fact the NGK started as JIS and then went to ISO. From what I've read regarding the ND, it is still JIS; ND's own spark plug sheets indicate that plugs that have the "+" designation are ISO and without that will be JIS. On the ND spark plug sheets there is currently no "+" designation. Either which way, the plug wires fit fine in fact it seems that the tip of the plug really sits tightly to the bottom of the wire with JIS plugs. I truly think the wires were designed to work with either and the 2.5mm tip is marrying up to 10mm or more of contact area so it shouldn't be a big thing. Please update what you think about the PK22P8's. Thanks.![]()
I still have the original plugs that came in my 80 which I bought new (in my spares box) and they are NGK BKR5EYA
I can measure anything you want off of them...
cheers,
george.
well if you measure from the seat to the tip it will tell you which style they are. 50.5mm is ISO and 53.0mm is JIS.
The confusing thing for me is that either type can be had of any particular plug.
In ND world it's the second letter that denotes which type plug it is.
IE: PK**** is a platinum ISO plug while PQ**** is a platinum JIS plug.
All the listings on both sites in there look up catalogs show an ISO standard plug and ISO alternates.
But maybe the socket in the plug wire will except either as Shaun has mentioned.
Rick, it is even much more confusing than that! Actually in the ND world the second letter specifically refers to the thread diameter and hex size (usually, not always). "K" does not always mean either ISO or JIS (usually, not always); for example the VK series, VK-G series and VK-Y series are all ISO, however, the VKA series, VKB series and VKH series are not ISO and some of them are not JIS either. To add to all the confusion, there are/were plugs that were K's or Q's with the "+" designation which were sometimes ISO regardless of the other letterings. I have even heard from my mercedes mechanic friend that sometimes ND used the "+" designation to refer to reach as in reach into the combustion chamber regardless of the other letterings! The whole thing is dizzying. In any case I'll confirm that both the ISO and JIS types fit our rigs really well without allowing any water to enter the plug's tube. And I also suspect that if one looks long enough almost every plug ND makes can be found in either ISO, JIS or altogether other arrangements! Again, dizzying to say the least. I wonder what george_tlc's plugs are/were, at this point with the wild amount of variation on ND's I'd say they could be either ... another interesting thing on them is that originally they were .032's and now the same things sometimes are .028 from the factory with no other character offering suggesting the switch! Wowsers what a headache I have now.![]()
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Ohh, another interesting thing is that ND won't recommend running Platinum with either Alcohol or Nitrous because the platinum tips pop off! The Iridiums however haven't had that problem.
well if you measure from the seat to the tip it will tell you which style they are. 50.5mm is ISO and 53.0mm is JIS.
The confusing thing for me is that either type can be had of any particular plug.
In ND world it's the second letter that denotes which type plug it is.
IE: PK**** is a platinum ISO plug while PQ**** is a platinum JIS plug.
All the listings on both sites in there look up catalogs show an ISO standard plug and ISO alternates.
But maybe the socket in the plug wire will except either as Shaun has mentioned.
NO s***! I put in something like 6 hours into trying to decipher what was going on. I ended up focusing on the current offerings and their nomenclature. The plug I picked was trying to find a plug that was the best gap-able one in the heat range you recommended. The one I posted was the best one I could find given that criteria.
They are actually a stock plug for a Honda Civic![]()
Ok, the Original Plug that came with my 80 when new, calipers to just a hair under 51mm from the seat (not including the crush washer) to the top of the tip, Now, does the seat include the crush washer or not? As per the measurement info at NGK.com - Spark Plug 411 they show measuring above the washer, but in the picture on the right it seems like the seat includes the washer ????
If including the washer I'd guess before the washer crushed the height would have been in the 53mm range...
Now I'm confused too
Again, the plug is an NGK BKR5EYA
cheers,
george.