Thanks for the pointers. I looked at buying nozzles and the option of sending mine in as well.
Duramax build and the machine shop.
- Thread starter Frogman1
- Start date
There won't be interference as they generally error on the side of it by taking .010 off the tops of the pistons compared to stock for a greater p to h clearance. Also gives room for decking the block (something I would for sure do). Problem is, if you don't account for p to h clearance, you can have a big quench area that is just going to waste fuel for the power you are after. These are cast pistons as well and do not need the clearance forge would need. I'd also keep piston to wall clearance tight (or on the loose side of stock specs).
So in other words, you could inadvertently be lowering compression even more than the 16.5:1 because of the grade c gaskets and not knowing where you want p to h clearance. This also increases quench which hurts mpg.
So in other words, you could inadvertently be lowering compression even more than the 16.5:1 because of the grade c gaskets and not knowing where you want p to h clearance. This also increases quench which hurts mpg.
Wow.. and the hole gets deeper! To hear that my compression could be lower and more wasteful by the gasket thickness choice among other things really takes things to a new level. I thank you for sharing the not so pleasant news that I enjoyed not knowing for a little. I might actually need to give the shop more money and have them ensure I'm getting the best build for what I've got parts wise. I kind of viewed it as plug and play, but now I see where the higher level knowledge comes into play. On a plus side, I'm waiting on some Cerekote to top coat the pistons so maybe a slight amount of dead space will be filled. I saw in an earlier post you asked, I did get a sump for the tank as well. I'll try and reach out to them at the machine shop tomorrow or Friday and I'll post here on the options. Thanks again for the education.
Frogman1 said:
Who Quoted you those Prices for my pistons? Way out of line.
Jon
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Jon,
no one specifically quoted me on your pistons. I search my arse off on forums and look at diesel parts suppliers trying to find out what parts are best and what prices I would end up paying comparatively. I saw the numbers cut with the oval bowls and then with reliefs customized as desired. I looked at your process and concluded you're taking the PowerPak uncut blanks and cutting the ovals, with or without valve reliefs as requested. Everyone who's running them expresses nothing but greatness. The only slightly negative statement I could find was about "a slight bit more unburnt fuel at lower RPMs than stock" on an LB7 I believe it was. The goal was to get the highest compression ratio on my LBZ possible without being to risky with my hopeful longevity and performance plan. PPE's biggest since they get Mahle to specialize for them and cut the lips off the bowls is 16.5:1 and the price was not beatable from what I could find. I'm new with this, and taking advice from the forum seniors that seem to have the most knowledge. I plan to Cerekote them when the paint arrives unless you have a better idea that will still allow me enough piston to head clearance. I'm using the "c" gaskets. The block and heads are factory untouched (not planed) and I didn't have plans to take the factory head gasket grooves off the block and reduce my piston/head gap. The machine shop has had the block since the 2nd with plans for cleaning, cylinder PSI leak test for pin holes, and to bore & hone to .020 over. My guess is they haven't started but I'll stop on by tomorrow and see.
Very cool to cross paths with someone local here. My being new to the Duramax game, I asked around shot in the dark and got referred so I'm just cautious is all. I'll give updates about the progress as I get it. I think I've possibly seen your truck around, probably waiting in traffic on 64:roflmao: ... or more likely by Big Woody's. I get out to Great Bridge often enough. Sounds like yours is nicely tuned.
just FYI, there are no factory "HG grooves", if there are, that is not a good thing unless its been o-ringed.
Each block cylinder bore has a set of fine rings (3-4 of them and not impressions from the head gasket) on the head face. I'll see if I can post a quality picture as I used a scotchbrite on a drill and was careful not to hit them too aggressively around the bores. I've never head of a block being o-ringed and I'll have to have a look into this. I see no reason as when I got this engine and began cleaning and disassembling it, the farmer did nothing special to care for it. I washed nearly an inch of dirt out of the valley. It did have strong compression as stated, a new welded gears water pump and a new rebuilt CP3 with a manufacturer tag dated April 28, 2015. no other mods noted and when I saved the factory settings to my PPE programmer, they were not modified. Let me find some pics.
Here's a picture of the rings. I hope the detail shows here or you can zoom. They are notable on each cylinder and the nail easily catches on them.
Attachments
those are just depression from the fire rings in the head gasket. i would want those cleaned off with decking the block. it will affect compressed gasket thickness and how well the fire ring seals. some reason your heads probably have a fine ring pressed into them.
Send your injectors and cp3 to Shane Roark, He turned my stock injectors into 100% overs and my stock cp3 into a 10mm stroker for a reasonable price! He is the Godfather of the Stroker pump in my opnion.
Just back from the machine shops. First one will have the crank keyed by Tuesday and "will do right by me price wise" for pushing the work off for a bigger job. 4.5 weeks now.
The shop with the block has had it cleaned and pressure tested ($250 wasted) and it looks unidentifiable and rusty compared to what I gave them. I couldn't believe it was mine so I took pictures of the numbers I could find on it to compare to what I have at home. Are the numbers in the valley (which are the same) engine serial numbers? I also grabbed a picture of a lightly etched number on top of the CP3 bridge that I'll compare to what I have. The machinist said those rings were from the gaskets as well. There's another D-max getting done with ARP main studs at the same time.
I got my studs back and am going to get it decked and bored/honed next week (just not line bored for $400!!!) when I bring the piston. Apparently they're needed before a very light decking ensure head to piston gap? How they could tell I can't figure out, because they would need the entire assembly, pistons, crank, rods and bearings to get an accurate measurement. They also spoke of the "Cometic gasket " option made to whatever size needed for piston clearance, but not to use that as an option to change compression ratios, but rather pick the pistons for the goal? As stated mine on hand are the PPE de-lipped Mahle PowerPak 16.5:1 .020 over kit riding on the Carrillos with Clevite H main and rod bearings. Just got the Cerekote piston spray in today and a BD thick flex plate from Thoroughgood Diesel. kind of thinking I should have asked around another week here for a little more specific piston advice and head-piston clearance earlier and possibly gotten something closer to 17:1 +/- . PPE was pressing me to go with 15:1 which from what I found would be way lower then the desired Daily Driver/HP/longevity goals.
I'll look up the name when I'm rolling again and tell him you referred me. It doesn't sound like too much work at all to just change out nozzles? Would a 10mm fuel 100% overs fully? How's your "not at the track" driving with the injectors? MPG, smoke, Boost psi, etc.. plusses and negatives?
Longevity of the pistons would not have been an issue with the Ovals, though the blow by can get high with the higher compression. (18:1 and higher) I sell the gapless second rings now to keep that in check, but that seems to be a big limiting factor in getting anything good out of the higher compression builds..
Jon, I did manage to get one thing right on the piston end of things thanks to your guidance. I called Socal Diesel after not being able to find their listing online and they took care of me on the Gapless 2nd rings. Wish I had reached out sooner on the build. Very much appreciated.
Best, Ralph