I have a few questions about re-assembly before moving forward. I put in new cam bearings, everything else looked good. I added a w-100 cam kit with the standard billet lifters, and new cam gear. My case is back together and I'm trying to finish the heads so I can put on the new cylinders and jugs. Here is a pic of my valve spring retainer, keeper issue. Both of these valves have the same size shim under them. Single HD Hi revs. I clearanced the keepers on one to space them out, and planned and doing it to all of them, but I'm still having an issue with how high the retainer comes up on the first one.
I had considered taking a dremel to the ports on these stock castings just to do some smoothing since it's going to be a turbo efi motor, is it worth the time?
Also when I took the stock pistons and cylinders off there were NO shims under the jugs. Just rtv. Since it's a stock motor can I just put the new jugs and pistons on, or will there be a compression difference? It had non forged mahle brazil? or something, and now I'm putting on their "forged" version. Staying 85.5mm.
Thanks in advance, this forum has been super helpful and I appreciate everyones advice!
You don't need near that much gap between the keepers to make them "grip" the valve rather than allowing it to rotate freely in them as it can when they touch. A slight gap at one end, say .015", when they touch at the other is sufficient.
After you sand/grind the keepers and test-fit each pair around a valve, try dropping a pair into each of your retainers and comparing how much they protrude from the bottom. They should all be about the same, if not there's inconsistency in the machining of the retainers. Besides making the installed heights (and therefore the seat pressures) of the springs unequal, there's a possibility of them "pulling through" if the hole in the retainer is too large. Try other pairs of keepers and see if there's any variation in their outside dimension. Hopefully selective fitting of the thickest keepers to the retainers with the biggest holes will compensate for the discrepancy. If the valvestems aren't the same diameter this gets trickier, but ordinarily it should be possible to make all of the retainer heights and keeper gaps match fairly closely.
Typically the piston deck height will be over .050" with no shim or gasket between the cylinder and the case. That's plenty for safety - .040" is considered the BARE minimum. .010" less deck height makes about 0.16 difference in the compression ratio of a stock(ish) 1600, for example an engine with 52cc chambers (and flat-top pistons) that has 7.52:1 at .060" piston deck would have 7.68:1 at .050". That's getting close to the maximum I recommend for a naturally-aspirated engine with a stock cam (on Regular gas, anyway) but no sweat with the W-100....that's assuming the heads have not had their volume reduced significantly by flycutting, to know for sure the chambers need to be CC'd. I don't have enough personal experience with turbo combinations to recommend a C.R. number to you, the amount of boost and the octane of the fuel you plan to feed it are major factors. Perhaps someone in the Forced Induction Forum could suggest a good target C.R. for you if you tell them more about your engine management and turbo size.
Put a stock metal gasket on each intake and note how much of the head is visible inside the holes - scribe a line with a sharp tool along the I.D. of the gasket and remove that much. Do the same thing to the manifolds using some bolts/nuts to hold the gasket centered. Having the ports in the heads slightly bigger than the manifolds (or gasket holes) is a lesser sin than having the ports in the heads larger and/or having the gasket end up protuding in - so match them all as well as you can but err on the side of the manifold ports being smaller than the heads or gaskets.
You could go bigger than that of course, using bigger-I.D. gaskets, but I doubt it'd be worth the added trouble with a turbo force-feeding the engine....just do basic port-matching to about the size of the stock gasket as described.
