You ever run into a situation where the lifter bore diameter is larger the the clearance you like to run ( We normally run .0020 )

We also run .002 clearance and yes to answer your question , we actually go through the quality control before we start on the blocks because a situation we had several years back were we machined a block start to finish assuming as we all do sometimes (its new so it has to be right) were the lifter bores were actually out of round at the bottom by ,008. We normally see bores come through with .0012 to .0015 but every once in a while we have to send one back. As long as the block is unmachined it can be returned as defective but once you touch it its yours. We have taken the precaution to inspect every block ever since. This is exactly the reason I want guys to see these post there are so many things a customer can ask the engine builder to do before they spend money on repairing the engines that would eliminate problems such as low oil press noisy lifters damaged bearings and so on. Thank you for your reply sincerely Laz

Not only will they not take it back because you machined it, you wasted all that time and labor Machining an engine that you are now not going to get paid for.

Could you sleeve the lifter bores? Just asking.

Thanks for the informative posts. I enjoy reading and learning.

Yes we can and in many cases were the block is being used for all out competition we sleeve them even if they are new with the right clearance this is to insure the location and angle of the lifter to cam is correct . Also aluminum blocks suffer from wear more so than iron blocks. Being that aluminum grows more than iron the lifter bore clearance is ultra critical. This is one of our specialties we're one of the leading shops in Florida for machine work and serve the engine builders as well as the machine shops from Daytona to Florida city. This is what sets the standards in the building of any type of engine not just racing engines. Thanks Laz

Thank you

Nice i have darts also. I had issues with oil drain back. The blocks dont have the the large hole at front of lifter valley like the gm blocks have. I had to use Smith brothers pushrods with .040 holes in them to limit oil to the top. This winter I want add drain back holes and lines in the heads to go straight back to pan. What are your views??

so on the Dart blocks vs GM blocks how accurate do the lifter bores tend to be in relation to location and angle?

As far as what we see the most of is the GM blocks are very unpredictable as far as size and location the Dart and Merlin blocks rarely come out but I've had Merlin blocks be out and Dart blocks big on the bore size as well so it's a catch 22 . That's why the proper procedure is check everything no matter who's it is and this way the customer will benefit in the long run. This is so easy to do but yet so many people refuse to do so( just because the engine was fine when it came in for rebuild) as they say when there's a problem . I say to the folks that are having engines rebuilt to ask the engine builder to measure and pay close attention and even provide a written report before the work is authorized. Some would think that's a pain in the ass but in essence it's the proper way to approach a job . Best of luck and thanks for the reply Laz

Terrific thread..