Cool, you do know those are .050" thick head gaskets right? I will be setting Andy's pistons .005" out of the hole for a .045" quench ring. We're using nascar take out rods so the center to center will be more accurate than the factory rods. If anything though the factory dimension tolerance was probably plus nothing minus maybe .015" ? Not sure what your rods are because I didn't think to measure them until now. Your machine shop should be able to measure them for you to get an accurate compression measurement? If the deck on the engine has never been cut more than likely it will be +.030" or more taller than the factory spec. The factory pistons were anywhere from 1.800" to 1.835" compression distance depending on year, the discontinued Federal-Mogul power forged C/H was 1.852" only .008" less than the Wisecos, but if you want to go with the JE because of the bigger dish should I undestand. Its so hard to bring the compression down on a sbb 350 with its tiny chambers, especially with everyone that wants to up the compression without milling the block, its getting harder to find the older cast iron heads that were never milled! Andy's block's deck measured +.029" on one side and +.032" on the other side, I think its a '70 or '71 block? The later blocks were even taller! His heads were only surfaced probably once some time in the past but still the chambers measured 54.5cc,so the custom 3.903" pistons for the Andy engine have a 35cc dish to get the compression down to 8.8:1. Derek
Measuring my pistons I am getting 1.839 for the CH. That sort of throws a wrench in my plans of bringing the piston closer to the deck with off the shelf pistons. I know the autotech pistons will do CH as requested but the dish is too small. And then to go with custom pistons from wiseco or someone else brings the price close to $1000, not money I want to spend while using stock rods. I am going to throw some pistons back in and get a few more measurements for deck clearance. I know the machine shop I plan on using does good work but I dont trust them as far as making deck height match on both sides and milling the intake side of the heads without me telling them to. I do plan on assembling the engine myself Is that measurement after the gasket is torqued? Beacause I am measuring .070" which is a bit more than I expected
Also double checked my deck height with pistons 1 and 8. #1 is .053 on outside of block, and .066 on inside of block. #8 is .058 on outside of block and .063 on inside
Pardon the intrusion... Are you using the same piston/rod for both 1 and 8 and if so, implying that there's .005" difference in one bore vs. .013" in the other from end to end across the piston? If you are measuring 2 different piston/rod combos using the throw of the crank you are not only measuring deck height, only stroke and component stack up. Might as well be a blind guess. A 12" caliper is maybe $40 for import. Measure when the block is stripped. You will love owning that tool anyways. Might be better off letting the shop measure it and record their #'s before instructing them to do it a certain way. Being able to verify their work BEFORE you assemble will save headaches later, rather than trusting your deck bridge and final component stack up. I wouldn't sweat quench if you are using a similar shaped dish. Probably out of the danger zone if @ .090" or more anyways (measured from the "not really quench" portion of the head) Just get what's available for pistons.
Thats true, why should I sweat it. I guess I just want to know how much shorter the quench height will be with the JE pistons, but if my stock pistons are 1.839 then it won't be an issue going with the JEs. So being new to all this, what should I have ready for the machine shop before its dropped off? I ordered the cam bearings, new arp rod bolts, main studs, freeze plugs. I didnt order rod or main bearings yet not knowing if the crank has to be resized or not and assuming that the rods will have to be resized with the arp bolts. I'd like to prep the block as best I can before the machine shop, remove casting flash, oil gallery plugs, do what ever oil mods are recommended (Reading Jim's oil mod thread gives me a good idea of what to do.) I think I'll be safe enlarging some things if I have the oil boost plate and adjustable regulator. As for the heads, I'll clean them up and do some light porting. I am going with the stage 1 valves so I'm not sure how far I can go before the seats are cut for the larger valves. I forgot to order valve seals so I'll add that in on monday. My head is spinning trying to just focus on one task because I am always thinking of something else I might need.
Clean it as best you can, if you want. They are going to charge you for it anyways, and your still going to have to clean it before final assembly. Before I could bore and hone, I avoided having them put cam bearings in because of the necessary washing, but that's because I have the tools to install. That's up to you as well. The most important part is that it's clean when it goes together! The only advantage to a larger valve IS to make the valve job a larger diameter, allowing a larger port throat with it. That's where the benefit lies. Otherwise the valve is in the way and often hurting airflow. It helps NONE to bring the OD of the sealing angle in more than .015" diameter or so from the edge of the valve, .005-.007" from the side. Ideally, you would want the sealing angle very near the edge of the valve, but leaving it a bit shy for various reasons. With a larger valve than seat... the valve is effectively just more in the way, and I would hope you wouldn't intend on wearing the seats to the point that they swallow the valve. NASCAR is making how much Hp with a 1.625" exhaust valve? The valve size isn't the problem, it's the port. A thicker margin valve or larger diameter will have an affect on valve stem height but the larger diameter would certainly hurt airflow without the right porting and valvejob. Unless your seats are dead perfect, count on having them cut. I haven't read the entire thread, so forgive me not knowing the condition of your heads. If you are going to have the seats cut you are better off getting SLIGHTLY bigger valves. It's like having fresh material to the machinist, otherwise they have to sink the valve job. Please avoid that. I hope this hasn't been confusing, it's much easier for 1 person to handle the entire build than several people micromanaging the details without a strong concept of the finished product.
I remember reading somewhere here that RPMs should be kept below 6200-6300. Higher than that and it's a ticking time bomb. Call it a 6000 RPM redline to play it safe. Higher than that and you risk everything. Gary
I don't think I'll see any benefit to spin it more than 6. It's a huge jump over stock rpm limit so even 6000 rpm will be strange
Head work is still a mystery to me, so any advice is appreciated. I've already decided on a rotating assembly so that is done. Block is stripped down so I will look into doing some oiling passage work, clean up some casting flash and then its off to the machinist. With the JE pistons and a .050" head gasket (based on what Derek has said about the gaskets) If I bring pistons to 0 deck my compression will still be low enough and if I am understanding correctly I should be setup to take advantage of any potential quench pad the new heads may have. I will cc the heads before and after port work to get a better idea on chamber size. I've been considering removing the machining boss in the combustion chamber to gain some more area and further drop compression. As for head condition these are relatively low mileage heads that don't show any obvious signs of wear. So my question is what port work and assessment can I do before the valve job, and what port work must be done after the valve job? Is there any information I must provide to the machinist to set him (and myself ultimately) up for success? I am already developing a list for parts I need to add to my TA order on Monday. Speaking with Tim there I had the impression that besides the stage 1 valves and springs I shouldn't need anything else for the heads. Thinking about it though I know I should do new valve stem seals, do I need anything else?
Thats the number 5 cylinder exhaust lifter bore. It doesnt look ideal and makes me a bit nervous. Is there enough meat there to continue? I have another block if need be. Got most of the deburring done though. Oil mods will be next week as well as head porting
Caps and locks are cheap. Do your porting work prior to the valve job. You can blend in the port work to the bottom angle of the VJ when they come back. Use pics from the board here, plenty of good info. Make certain any sharp edges of the combustion chamber are fully deburred after surfacing. A couple of carbides from Enco or MSC and a flap-rod is all you really need, maybe some stones from the Hdwe store. You obviously have some stuff if you are deburring the block. You won't have a radical enough cam to hurt that lifter bore. Make certain a lifter will easily slide around, I've had a bad bore prevent a lifter from spinning. Use an old one to check. A trip to the CNC solved that one, cut to the Ford size...used Ford lifters on the GM cam.
I did order some carbides and cartridge rolls. Carbides are sweet, never used them before but they sure make the job a lot easier. I'm happy with the lifter valley. Lifter doesn't hang up in that bore. I was just nervous as I thought roller setups were harder on the valve train. I am excited and nervous about starting the port work but I should have all the right tools for the job so that should make things smoother. No pun intended.
I don't really use cartridge rolls much anymore, even though I have bags of them. Maybe on aluminum. Gotta go kind of slow and easy to avoid destruction. I didn't read all the thread to catch the roller cam or specs. It is harder on the block. I also haven't built one wild enough to know at what point those start breaking, if it's even a problem. Can't tell by the pic which direction the cam will spin or which way it's pushing the lifter. Might want to visualize that.
Still on the fence about the block, maybe next weekend I'll take my other motor apart and go with that instead. Waiting on parts from TA still as well. I messed around with a switch panel I bought and had a hard time deciding where it would go. I ended up removing the ashtray and trimming the switch panel to fit. Its not perfect but it is certainly better than my plan to cut a hole in the dash...
Well guess my mind had been made up for me on the block. Found a crack. So I'll go with my early 72 block. I believe the heads should be the same between the two even though they have different casting numbers. I noticed that the earlier block doesn't have the coolant scallops but I don't think that will be an issue. I think I'll also use the crank from the other block as it has less miles on it I believe the counterweight are slightly different as the early crank hit the cam as I was taking it out. This earlier block has been rebuilt. It has different pistons and the connecting rods have pry marks between the caps. The Pistons sit .104" in the hole. Seems like it's a set of those shorter height stock replacement pistons. Will there be any issues using the late 72 heads on the early block? I have to balance everything anyway so I'm not too concerned with using the other crank with my cap screw rods and forged pistons
The late 72 heads (marked 73) have no coolant ports in the center so they will be good to go. I am sending my connecting rods to TA to have them reconditioned. I don't want to worry about having my local machine shop do it since they will already have plenty of machine work with the block and heads. I'll port the heads while I am waiting for the rods and just bring everything to the shop at once
Don't panic. This is just a practice head. It's definitely a steep learning curve for me. I have to learn some patience and I have to anticipate things better. While definitely large enough this port isn't uniform in shape and there were a few places I have struggled to get smooth. I might work it a little more but I definitely need more practice.
Whew, good to here that is a practice head!!!! You don't want to take material off of the bottom of the port, just want to take off the casting flash and irregularities. Don't worry about getting the intake runners smooth, save that for the exhaust runners. The intake runners seem to mix the fuel better when they're NOT smoothed out. Some head porters actually fill the bottom of the port with epoxy and raise the roof to make the airflow a straighter shot to achieve better flow. The less the air has to turn the better the flow will be for the intake side. With the floor epoxied and the roof raised the short turn radius work is easier because you basically just line up the short turn with the ramp that was created for that straight line of sight so the air doesn't have to turn as much. Seeing how you're probably not going to use any epoxy when you port your heads just keep in mind to try to keep most of the material removal off of the top of the port and the walls of the port. And remember that the port will only flow as much air as the smallest point in the port. A small investment in a set of inside dividers would help a lot to keep the ports uniform all the way to the bowl area. Un-shrouding the valves in the chamber would also be helpful to getting the flow in the chamber. Its a good idea to place the head on the block and scribe the circle of the bore onto the head so you do NOT un-shroud in the gasket sealing area. I'll stop writing because I'm not sure what you do or do not know, if you have any questions feel free to ask. GL Derek
Ah, bringing a tear to me eye...someone is finally listening to all the advice I gave in the past. :grin: Gary
