Seeing how you have the flat tops these head gaskets are a little pricey for your build and probably a little overkill for your needs, but they would help get compression down some if you need to, to be able to run pump gas; http://www.buyracingparts.com/gaskets/buick-350-severe-duty-head-gaskets.html GL Derek
I'm sure you engine builder has a way to calculate compression but average estimates are a 58cc head,.090 piston depth, zero piston dish with a .043 head gasket . that makes a 9.7 compression. Many people have used those pistons for street. You would need to measure to confirm your spec but you should be close.
This is definitely outside the context of a thread like this, but for creative inspirational purposes... Sean, what I'm getting at is that there is a quench pad there but you have to either mill quite a bit of the head away or put the piston WAY positive to use it. This has been done for decades. It was enough of an issue with Mopar BB before aftermarket heads became "more" affordable that pistons were made as "step head" dome to quench that portion of the head. Sorry for the derail.
Dynamic compression is actually pretty easy to understand. On the compression stroke, when the piston is on the way up the cylinder, the intake valve is still open. No compression can be built until that intake valve closes. It closes at some point as the piston moves up the cylinder. When the intake valve closes, there is less than the stock stroke left. The Dynamic compression is computed from the stroke that is left. That stroke is called the Dynamic stroke length. This article explains it all, and it has a neat calculator to figure everything out. http://www.empirenet.com/pkelley2/DynamicCR.html I keep it on my desktop so I can use it to figure all that out with any static compression and cam. Different cams close the intake valve earlier, or later. Earlier closings increase DCR, later, decreases the DCR. Advancing the cam closes the intake valve sooner, increasing the DCR. Retarding the cam closes the intake later, decreasing DCR. If the DCR is between 7.5 and 8.4, the engine will run on pump gas (theoretically). It is more practical to stay close to 8.0, if not a bit less. Once you get close to 8.4, everything needs to be right on the money, zero deck, polished chambers and piston top, cool running, and perfect fuel mixture and timing, as you are right on the edge of needing race fuel or a mix at minimum.
Decent info Larry. I think he will be ok at slightly over 10 to 1 since he has a turbo regal convertor(should stall about 2500 on 350) 2004r trans and 3.73 gears.
Just about ready to put in an order to ta 2 questions. 1. should I spring for a head bolt kit? 2. With the added bore how do I order the head gaskets? Should I go with the copper set?
OK I have gotten number two answered so all good there. Should I also wait for main and rod bearings until it is all pulled apart?
I would not bother buying new bolts I would either re-use the stock ones or go with a ARP head stud kit (but you should be fine without the studs). Yes I would make sure you have the main and rod journals measured before I ordered bearings as you do not know if the crank has already been cut or if it needs to be cut or not... have the machine shop tell you what machine work is needed and then order bearings accordingly.
.030 over is fine for felpro headgaskets. Get thread cleaning tap and dies. Clean threads on head bolts and threads in block. Use a few drops of oil on head bolt threads. Clean threads in rocker stands also.
Well, as I thought this was a little over my head I took it to a gentleman who will be doing the work for me. I am getting all of the parts, but I really did not want this to turn into a disaster so I am leaving it up to a pro. The only thing I'm waiting on is specs on the pushrods, main, and crank bearings. Hope to be up and running by April at the latest. I also plan to send the carb off to Ken and get a dist. From Jim.
It's at the machine shop. Hoping it can be up and running by the end of april. Heads should be almost done. Just need to order rod bearings and pushrods when I get that info back from the machinist.
Hoping to have my motor at the machine shop next week. It's exciting so many small block builds. If you haven't already bought that stage 1 intake it's time to switch to the sp3! Should be shipping out some time in may
So, I just called the shop. Machining is done. Cleaned up to .030 so the pistons will work out great. He's hoping to start assembling the bottom end tomorrow or Monday. He actually already ordered the rod and main bearings so I don't have to do that. No cleanup on the crank needed either so all stock size there. I called the guy with the heads and hoping to hear back tonight. Carb is back from Ken who took about 2 weeks less time than I expected which was incredible. Sending in an order to TA for the pushrods, break in oil, block paint, 5/8" pickup tube, pickup tube gasket, oil booster plate kit, and adjustable oil pressure regulator. That news just made my day honestly. I'm so happy there's so much progress being made. I honestly have this nightmare of not being able to drive it at all this summer so any progress is exceptional.
That's good news. Things should go kinda quick from here. What are you using for distributor? Curve kit? Electronic conversion would be a good idea.
Nice. Get all the little things together like belts and hoses. Spark plugs. Be ready to drop in. What torque convertor do you have?
Torque Converter is a D5. One more thing. I ran the calculator that Larry posted and it comes in at 7.4 DCR. That seems low for what I am doing, but I am also just using the standard information that I can get my hands on. So basically it comes down to this Adv. Intake Duration: 284 Adv. Exhaust Duration: 288 Lobe Separation: 110 Lobe Centerline: 106 (degree cam 4 degrees) Intake Close ABDC: 68 Crank Stroke: 3.85 Rod Length: 6.385 Dynamic Stroke Length: 2.9 Bore Diameter: 3.83 Chamber Volume: 58 Head Gasket Thickness: .043 Head Gasket Bore: 4.385 Piston Deck Clearance: .09 Dish: 0 Calculated DCR: 7.395 What am I doing wrong?
Is that the right gasket diameter for a 350? I only skimmed the thread, forgive me if I missed something obvious.
