Double pumper carbs and bore wash?

[ian_uk1975]

Guys,

I'm looking to buy an AC Cobra replica with a Ford 351w. The engine spec includes Edelbrock Performer RPM intake and GT40 iron heads. Originally, the engine was supplied with a 600cfm vac secondary carb, but the current owner changed it for a 650cfm double pumper and this has me worried. Some guys on a Cobra replica forum have scared me with stories of premature bore wear with double pumper carbs due to overfuelling and bore wash. I must admit, when I went out in the car, the fumes from the sidepipes were quite heady and the car banged and popped on the overrun. The engine has covered a total of 11k miles, but I'm not sure how many of those were on the DP set-up (guesstimate around 7k-9k miles). There was no blue smoke from the exhaust and the owner claims it doesnt use a drop of oil. Also, the engine did feel very strong when he gunned it.

What do you think?

Cheers,
Ian.

[mrmustang]

Ian,

If the carb is too big for the engine, and is set up improperly, you could wash the cylinder walls down with fuel causing premature wear of the engine as the gas mixes and thins out the oil lubricating the engine. First thing you want to do is pull the oil level dipstick and check for a raw fuel smell on it, if it's there, and it's heavy, then walk away from the car as the oil is most certainly contaminated, for how long is anyones guess. As for those members on a "cobra forum" making you worry, hogwash......Stop over at this sites sister site http://www.clubcobra.com and you will see the difference in actual knowledge vs the ukcobraclub.com web site..............Again, not putting anyone down, just giving you the very basics you need to assist you.


Bill S.

[ian_uk1975]

Ian,

If the carb is too big for the engine, and is set up improperly, you could wash the cylinder walls down with fuel causing premature wear of the engine as the gas mixes and thins out the oil lubricating the engine. First thing you want to do is pull the oil level dipstick and check for a raw fuel smell on it, if it's there, and it's heavy, then walk away from the car as the oil is most certainly contaminated, for how long is anyones guess. As for those members on a "cobra forum" making you worry, hogwash......Stop over at this sites sister site http://www.clubcobra.com and you will see the difference in actual knowledge vs the ukcobraclub.com web site..............Again, not putting anyone down, just giving you the very basics you need to assist you.


Bill S.

Bill,

Many thanks for your informed reply.

I'm not unaware of the issues of bore wash and it makes sense. I'm hoping the engine I'm talking about isn't overfuelled to the extent of major bore wash because it seemed to run fine even from stone cold. The car started right on the button (I didn't even hear the starter crank) and, when warm, it cruised fine at <1,500rpm in 4th gear. Good tip about the dip stick... I'll do that.

Cheers,
Ian.