How I Do It --- Piston Deck Height

Small Block Chevy
How to measure piston deck height or in other words, how far is it in the hole? (or out of the hole).
Music used by permission.
Copyright Kania Tieffer Music

[@vrm86gt]

Thanks Karl!

[@brianf8621]

Always great information.

[@EllweinEngines]

thanks

[@halim1644]

hey ive seen alot of tuning you made, using plasticine to check valve clearance, using degree wheel and etc.. looks forward for your next quality upload !

[@EllweinEngines]

Thanks. That was the very first time I did the valve checking spring method. I'm finding it difficult to get camera time and editing time but still there are countless tech topics to go over in the future. I do think the clay method was quick and easy.

[@halim1644]

@@EllweinEngines do you have topic on cam duration and compression ratio with valve size and flow.. im building a small single cylinder engine

[@EllweinEngines]

@@halim1644 That will be a bit over my head. Cam duration and dynamic compression ratio...that is over my head and I leave that to the cam and head designers like Lloyd Elliott and Dennis Staff.

[@wreckanchor]

Karl: Does the cranking compression vary much between cubic in blocks using the same piston? Say 327 vs 400 sbc? I am trying to wrap my head around how to order pistons for a 400 sbc for good performance but also managing cylinder pressure. I imagine the only 100% way is to put the pistons and rods on the crank and in the cylinders but I dont know?

[@EllweinEngines]

Yes. Well, static compression will vary. I guess cranking compression is a function of the camshaft.

[@frankrizzo2724]

Good video. Strange music.

[@RoundedNutzGarage]

Good music while high, which i am rn

[@halim1644]

One question.. Why need to check depth clearance?

[@EllweinEngines]

Good question. Basically for a new engine or rebuilt engine it is nice to verify if the piston is flush with the block deck or a bit lower or maybe even above the block deck. Most of the time the piston will be right were it was supposed to be when you buy the proper parts and the block is machined properly. But you still want to verify just in case something is wrong. Also the piston "deck height" is part of the compression ration calculation. So to get a good valid compression ration calculation you'll need to know where the piston is (how far down in the hole). The gasket thickness can be adjusted to get the exact piston to head clearance too.

[@tylermonette1442]

How do I do a domed Honda piston ?

[@EllweinEngines]

Good questions. I really don't know.

[@gregleenyit]

Isn't that a bit far down in the hole ?

[@EllweinEngines]

Not that I prefer the piston in the hole that far but I prefer to "NOT" deck the block to zero. I deck the block to the minimum required for flat and that is usually only 5 or 10 thou. That helps the intake manifold fit better.

[@shaunfeldman3964]

Most machine shops go .010 away from zero deck incase you ever have a boo boo and need another deck job. Unless customer wants true zero deck

[@KingJT80]

@@shaunfeldman3964 most pistons are made for 0 deck....esp SBCs....because most people just "0 deck" the block