direct 2bbl problems

[pcoup41]

I have a 66 200 block with the original head and the classic inlines 2 bbl adapter and autolite 2100 which ran great. I found a hex log head and had the intake milled for a direct 2bbl. Since I have done the swap it is running lean and I have valve tick. I was orginally running the new head with original rockers and pushrods from my 66 head. I later put in the rockers and pushrods from the newer head thinking they may be different and it did not fix the valve tick problem. I do not have the tag on my carb but it is off a 68 289. any help is greatly appreciated.

 

[CZLN6]

Howdy Pcoup:

I'm guessing that you did some machining to the new head to raise compression, or you used an after market head gasket on re-assembly, or both. Most likely the end result is too much tolerance in the valve train for the hydraulic lifters to accommodate. I guess I should ask, were both sets of rockers the non-adjustable type? If the above is true, that could account for the valve noise. IF this is the case, you will need to hunt up a set of adjustable rockers and push rods.

As far as the carb going lean, again a change/increase in CR could reveal that. Look on the side of the float bowl for a small circular casting with a number inside of it. It will most likely be 1.08, if it is from a '68 289. Also you should verify what main jet is in the carb. You could try richening the low speed air screws and raising the float level.

Also, what distributor are you running? How much initial advance? How did you determine that the carb is running lean? What vacuum advance source are you using? Do you have other engine mods?

Adios, David

 

[MPGmustang]

lean, have you checke the mounting surface for vacuum leak between adaptor and head, or carb? little carb cleaner while idling will let you know if there is one. spray at an area a short burst of cleaner, if the idle changes (up or down) then you have a vacuum leak. little RTV can fix that.

David probably covered everything else... Good Luck!!! on the later head score!

 

[pcoup41]

thanks czln6 and mpgmustang. I think I found my leak under my spacer so that should solve my lean issue. As for the head I have a fel-pro set from autozone, the head had been milled(i dont know how much) but the machinist said he took more off than planned because it was a little warped, which still does not explain the valve issues im having. Both sets of rockers that I have are non adjustable so I will need a set of adjustable rockers and pushrods. Does anybody have a set or point me in the right direction? Also what did adjustable rockers come on? thank you

 

[Soldmy66]

In an old (circa 1967) magazine article Ak Miller said used a 1/2" flat washer (60 thousands thick) under each rocker until he upgraded to adjst. rockers. That might help in a pinch.

 

[CZLN6]

Howdy Pcoup:

The FelPro head gasket is about twice as thick as the Stock OEM steel shim gasket. That would add .025" clearance to the rocker geometry. Typically a head will clean up to level with a .010" mill cut. It the machinist took more off the question will be how much. What ever he took off the head can be subtracted from the .025" additional gasket thickness. I'd see if I could get him to guess at the amount he took off. My guess is that with the thicker head gasket and normal wear, you have too much clearance for the hydraulic lifters to take up. And adding washers, ala Ak, would only make it worse. The best solution is the adjustable rockers. A little lifter noise won't hurt for awhile. It is not a good long-term idea.

Adios, David

 

[pcoup41]

where can I get a set of adjustable rockers and pushrods?

 

[Crosley]

where can I get a set of adjustable rockers and pushrods?

Check with Mike's web site:

http://www.classicinlines.com/

 

[pcoup41]

I dont have that much to spend on rockers. Does anybody have a used set?

 

[Invectivus]

The problem is, you aren't just looking at rockers, but new cup pushrods too. that kicks up the price a bit. Hoping to hit some of the picknpull's in the outlying areas, like chico and merced (they have some old falcons last time I checked) and I'll grab them for you if I find them, at cost plus shipping.