redzedsled

Hello! I bought my sound deadening sheets from Lordco in Canada. They were a ProForm brand and were the perfect size at 29" x 32", with 2 pcs per package. Here is the link to their website: http://www.proformproducts.com/en/products/repair-products/sound-proofing/sound-deadening-sheets/ Regards, Rob

The FelPro head gasket should not require re-torquing I have understood. I was going to go FelPro as well until I talked to Dave Rebello who suggested the 11044-N4221.

I found this very useful calculator for Datsun L-Series Engines. Here is the link: http://www.ozdat.com/ozdatonline/enginedesign/ With all the stock presets (E31 head, P30 block, etc) and a 1.25mm head gasket, it calculates the deck clearance at -0.100 mm (-0.004") below deck. Note the stock Deck Clearance Presets with the different engines, L24, L26, L28 etc. All dimensions on this calculator is in mm. Here is a link to a convenient length converter: http://www.onlineconversion.com/length_common.htm

This is my source for my information: http://www.jspecauto.com/files/jspecautotechcenter11d.htm You did say and I quote "MOST Datsun motors have positive deck height(.020) for a reason" Making mention of other L Series Blocks is relevant in this case.

After reviewing page 126 of the book how to modify DATSUN 510 610 240Z engine & chassis by H.P. Books, it states: "Deck clearance should be from zero (piston flat even with block deck at TC) to +0.015 (out of the hole) with the piston centered in the bore. This assumes that you are using the standard Datsun gasket which is about 0.050-inch thick when compressed." madkaw is right, after some thought, in that I could have gotten away with pistons that were 0.020" out of the hole (0.030" piston to head clearance). At the same time, I went with zero deck height on good advice of others and also because that is the way I uncovered the engine to begin with. If I have zero deck height along with a 0.050" thick compressed gasket, then I have more than Nissan's minimum requirement of 0.035". This is my first engine rebuild, so I am learning alot along the way. Admittedly I don't have the same experience of other members of this club.

I appreciate the mediation... If I am at zero deck height and I have a stock gasket that compresses to, let's say 0.6mm, that is 0.023" piston to head clearance. Perhaps with the new generation of head gaskets perhaps the compressed thickness is about 0.8mm, that is 0.031". If stock minimum clearance as stated by Nissan is 0.035", how could you get any closer than that.

The engine builder used Mitchel specs I believe he said, and insisted on 0 deck height. There is great deal of difference of opinion, for such a small amount of deck height. What's done is done now...

I made a decision based on many people's opinion, including the engine builder, the members of this forum, and people in the business. The builder felt more comfortable turning the piston tops down. I am aware that you can run your pistons over the top and understand that 30 over would be the danger zone. I debated turning the pistons down versus leaving them as is for several days. I made the decision, and now I will have to live by it. The goal of this thread was to inform others who could have potential issues with ITM pistons of their own.

No excuse for me to edit a posting (I changed it back to what is was), but I did later state it was 0.020 out of the hole, that I did not edit. Getting back to the matter I found this bit of info on L Series Engines, very few with positive deck heights. "Assembled stock engine deck height L16 ('68-'73 510 and later years 521pickup) piston deck height: 0.10mm (above block) L18 ('73-'74 610, and 620 pickup truck) piston deck height: -0.55mm (below block) L20B (various '75-'80 610, 710, 200sx, HL510, pickup truck) piston deck height: -0.45mm (below block)" and further... "most of the L, Z series have the piston slightly below the block deck at TDC"

Yes I did. Initially in the first few postings I estimated at 30 over the block and in later posts I stated it was about 20 over the top. Looking at How to Rebuild Your Nissan Datsun OHC Engine book, it states: "although the piston may extend slightly above the block 0.001 for example clearance is required to prevent piston from striking the cylinder". So what is the actual spec on stock deck height, is it really + 0.020? I have read differently.

I respect your humble opinion, but +0.020 deck height is not the standard from what I have known. When I initially pulled the head off the block, the piston at TDC was at the very top of the block, zero deck height and no higher. I have seen in engine calculators online and they suggest that the pistons should be slightly below the block at - 0.1mm, stock for the L24. I have always thought it was the performance guys who wanted the positive deck height and therefore run thicker gaskets to gain the clearance. The gasket I am going to use is about 1.1mm thick so compressed it should be about 0.6mm or so? Nissan's requirement is 0.035" minimum clearance between gasket and piston top. I respectfully take all opinions into account and then form my own decision, so I welcome your comments.

I did say .020" piston out of the hole in my previous posts did I not.

I had the pistons turned down 0.020" and now enjoy zero deck height. Now I can run a stock head gasket, part number 11044-N4221. Pickup the block and and head on Saturday from the engine builders. Thanks to all who contributed, I hope others can gain what I learned from this thread.

There's one listed on ebay right now if you search the part number. Actually there's two, one at half the price as the other, Genuine Nissan.

Here are some pics for you. The far right image is with the new gasket over top the old one for reference.