Sprint Plugs

[samgamgee911]

Hi, What's the differece between Bosch Plugs H6DC and H7DC, will either work OK?

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[samgamgee911]

hi - ( first sign of madness - answering your own posts) - after some research it seems to be a slight difference in the plug operating characteristcs as regards temperature. I believe the recommended Bosch plug for a Sprint is H7DC but I can't find a reason why a H6DC would not work either.<br>


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[Carsreunited]

I think the lower the number the 'colder' the plug. I think I've had 6's and 7's in my car. We switched to 6's at one point as it was having trouble starting from cold. <br>
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I'm probably talking tosh though!<br>
<br>


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[SprintMWU773V]

The number usually relates to heat range but whether it's high or low depends on the manufacturer. Champion for example orignially quoted a BN7Y for a sprint but now a BN9Y is quoted which is slightly "warmer". You can't get BN7Y's any more. Interestingly the NGK equivilent in cross reference is BP6EF but if you cross ref a Unipart GSP381 which was another original spec plug you get BP7EFS. I actually use NGK BP7EFS which doesn't have the v groove electrode but does seem to be slightly "cooler" than the BP6EF plugs. By "warm" and "cool" plugs I mean the abillity of the plug to remove heat from the combustion chamber. A plug cannot create heat merely remove it.<br>
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To understand spark plugs have a look at either:<br>
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http://www.sparkplus.co.uk or<br>
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http://www.ngk.co.uk<br>
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There are guides on there as to what spark plug numbers mean.<br>
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Fraid I can't comment on Bosch plugs as I haven't used em for years in any car.

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[george]

go to your local factors and look at the plug application book (ask first) and there should be a heat range chart in there

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[HJon Tilson]

The OE spec for dolomites was N11Y.<br>
Ive used N9YC's for years or the equivalent BP6ES.<br>
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The N11Y has a longer reach...I found some the other day and was thinking of going back to them on a car that is a tad more fluffy when warming up.<br>
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the TR7 cars both run BP6ES and are fine on warm up, due to the superior HS6 carbs I suspect.<br>
<br>
Jonners

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