jt1

While my motor is apart, I decided to have the heads flowed. I bought these as bare castings and had them assembled by a local machinest. Canfield listed flow #'s on their website with a "mild bowl blend", so before assembly, I smoothed out all the machining ridges where the seats were installed, blended machined areas to the cast areas, streamlined the valve guide boss, and smoothed up rough areas and parting lines in the castings. I probably put about 6 or 7 hours work in the heads myself. I was curious if the heads flowed the advertised #'s, and if my backyard bowl job was reasonable. I've heard some of the 5.0 ford crowd say the canfields weren't anywhere close to the advertised #'s, and wanted to see for myself. SF 600, 28", radius inlet on intake, 4" cylinder fixture, 1 3/4" pipe 30" long on the exhaust, 2.05 & 1.60 Ferrea valves. Here we go: Intake Lift Adv Actual 200 145 145 300 201 197 400 247 245 500 258 255 600 259 259 Exhaust Lift Adv Actual 200 107 110 300 143 143 400 175 169 500 190 185 600 200 196 I was pretty pleased, the actual #'s are very close to the advertised ones, and apparently my home bowl blend didn't screw anything up. These variations are well within what could be expected between different benches and minor differences for the valves, valve job, etc. This guy also has a Superflow SF901 dyno, so I'm going to get her put together and take her to the water pump in a couple of weeks. More to come...... John

Are you using the rubber seals that come with the intake gaskets? When a block has been milled sometimes they can hold the intake up enought to cause leaks. If so, throw them away and run a big bead of silicone across both end rails of the block. Also clean all surfaces with ether (starting fluid) before applying sealer. I use silicone or Hylomar, can't tell much difference. John

Comp will rebuild the lifters, I don't know how they charge. Find the culprit and take it apart first. It may be just a piece of crud in the oil passage or plunger. If so, clean it up and reassemble and you're ready. Be careful taking it apart, sometimes the plunger springs are pretty stiff. Usually the only time you need to rebuild lifters is when you're running mega spring pressures and the axle bearings start getting rough. John

Possibly a collapsed lifter- i.e. the plunger in the lifter is stuck down and not taking up the slack in the valvetrain. Run thru the valves like you're adjusting them, trying to shake the rockers. When the intake starts to close, check the exhaust, when the exhaust starts to open, check the intake. If you find one with a lot of clearance, that's the one. Sometimes you can take apart the lifter and clean it good and fix it, sometimes it takes a new lifter. Also, when you checked for loose rockers did you run the the valve adjustment sequence, or check with the motor in one position? If a rocker is slightly loose, it might not show up unless the lifter is on the base circle. Might recheck that as it's the easiest fix. John

If the higher dot fluid affects pedal feel it will be very little if at all. The main advantage is higher boiling points for track use. Valvoline Syntech is a dot 4 fluid with pretty good boiling point, and it's 4.99 a quart at autozombie, so you can bleed it regularly without breaking the bank. For street use, you shouldn't have to bleed them much, maybe once a year. John

It looks like the 057/058 # is the bosch #, then the bosch USA # is 17014. Which # did you use to order, and where at? John

Mine has: 021 906 262 and 0 258 007 057/058 and 390201 stamped on it. Nothing 10 digit by itself. John

I saw on another site the LS7 is a dry sump engine, although it doesn't say in the ad and you can't tell by the pic. If so, the dry sump setup is probably 2-2.5K easily. Anybody else seen this mentioned? John

Somebody out west needs this one, a perfect candidate for a V8 swap. http://cgi.ebay.com/ebaymotors/240z-1973-Datsun-Project-Car-Low-Reserve-Extras_W0QQitemZ4562714809QQcategoryZ6187QQrdZ1QQcmdZViewItem John

I bought a block from a guy in CA, got it shipped back to NC by American Freightways for $256. The reason I chose them is them had a terminal in the same city and picked it up at the guys house with no problems. Any company that has a location close to the seller is probably gonna be the best bet. John

You're welcome, big guy. Just my reaction to seeing that awesome looking piece while I'm reflecting on my two working guages, one of which is duct taped to the steering column. Beautiful work, as always. John

You Suck. :biggrin: John

Interesting. I would never have imagined that the clearance at the pin end sides of the pistons would be enough to allow that much rock. It would be cool to talk to someone onvolved in the piston design and see what's the reasoning behind that. I'm glad the pin clearance is OK, that had me worried. Sorry for the false alarm. John

Sir, I humbly bow in the general direction of Duncan.........nothing like having your own dyno......my hero!!!!!! Is this a for profit venture or strictly hobby? John

Welcome to HybridZ. It's nice to see a new member with an intelligent first post. That's definitely a unique car, as Tim said. Lots of nice metal work, I take it you're pretty good with a "wheel"? Believe me, you won't miss it a bit!!!!!!!!!!! John

Piston/pin/rod clearance should be on the order 0.0007 to 0.0009. If it's right, there's no detectable play in the piston assembled on the rod. The 1 or 2 thou you can get with the piston in the bore is probably moving the piston slightly in the bore, not rocking the piston on the wrist pin. John

Pete, what comp ratio are you shooting for? Since you've got dished pistons, quench isn't a concern. Shoot for the desired CR and adequate P/H clearance with the gasket thickness. John

Remember to always close the bleeder valve before the pedal bottoms out, so fluid is still flowing out as the bleeder is closed. This prevents any air from being sucked back into the caliper. John

Somehow I missed that the deck heights varied so much from one bank to the other. That sucks to have to buy two different gaskets. I guess one way to look at it is you'll already have a set when you freshen it in the future. Pull one rod and piston out and see if you can detect any motion between the pin and piston. The pin should slide smoothly in the piston, but you should not be able to detect any movement at all perpendicular to the pin. With a pressed pin the pin should not move in any direction in the rod. John

Pete, that amount of rock from the valley to the outside is not uncommon with short skirt/high pin pistons. It's one of the disadvantages of the combo. It sounds like with the piston square in the bore you have 10 - 11 thou + deck height. It would be better if it averaged about zero, but the block may have been previously decked. I have used 35 to 40 from the average piston height many times with no bad results so far. There will always be a few thou variation unless the machine work is super close Cup style stuff, and all the variations in the components are worked out, so don't sweat that too much. I would use a ~ 50 thou thickness gasket with what you've got. The fore and aft rock worries me. IMO that shouldn't be over 2 or 3 thou. It sound like the pin to rod clearances are excessive, or less likely, the pin to piston clearances. I know this isn't what you want to hear, but I would tear it down and have that checked. About a thou or a little less is desirable, and I can't see how you would get that much fore and aft rock unless the clearance is excessive. If the piston/pin/rod clearance is excessive, that baby won't run long. Maybe Grumpy will look at this, I'd like to hear his thoughts. John

I've done it several times playing racquetball too. After the swelling went down, the whole outside of my foot, ankle, and calf would turn bluish green and take about a month to get back to looking normal. After you do it once and loosen the tendons and ligaments, it happens easier the next time. Ice, rest, elevate, and if the swelling doesn't go down pretty quick see a doc. John

There's really no break in to the bronze gears. They are definitely a wear item and you have to monitor them closely. Usually the first one goes pretty quick, then then each succesive one lasts longer. At first, check it every 500 - 1000 miles to get a feel for how fast it wears. You probably didn't hurt the bearings, but there's no sure way to say without looking at them. I would run it another 500 miles or so, then change oil and cut the filter open to look for any debris, and keep an eye on the oil pressure. If the oil pressure stays good and there's no shiny flakes in the filter you're probably OK. John

I've got 250F/275R with Illuminas. With the shocks on 2, it's very firm but not teeth chipping level on the street. Fine for short trips, but would get old on a long trip/rough roads. With the shocks on 5 it works well on the track, probably as stiff as you want without major chassis stiffening, which I don't have. John

Why only 30 deg total? Lots of times the best results are with 34 -35 deg total. You might play with that some and see what happens. John

A guy here in NC has a 280 with a Maxima diesel in it. Says he get 32 mpg on the highway, with reasonable power. Pretty wild to see a Z pull up and hear the diesel rattle. John