D.Hearne said:A 2J2 is a head that was cast on the 2nd day of september 1972 which means that you've got open chambered heads, they're considered to be early 1973 heads or late 72's
D.Hearne said:Naw, Ford's don't need all them extra #'s.To much extra weight
D.Hearne said:Well if it's got solid lifters, it's easy to tell.If you push hard enough on the pushrods on a hydraulic cammed motor, you can depress the lifter plunger, with a solid you cant move anything. If it does have solids, then just adjust the lash cold at about .015-.020.
D.Hearne said:The comp ratio on this 400 is now 9.7 to 1 ( if my calculations are correct) We've set the timing everywhere from 8 degrees initial to 12-14. Pings like crazy with 87-89 octane at 12-14, 93 octane cuts the pinging almost out. Backing the timing down to 6-8 gets rid of it too, but cuts the power as well.Can't run a colder T-stat due to the forged pistons and a little too much piston to wall clearance. Motor will rattle soo much you can't stand the noise. But it does run like a spotted ape.
The problem was , there was no quench, none whatsoever. Even though I used a set of speed pro forged flattops for a 351C, they were still .050 down the bore at TDC, this combined with an open chabered head, and a .040 thick head gasket guarantees there's no quench. Your combo of quench heads and a big cam should allow you to run your 351C on pump gas without adding anything. Probably would run on as low as 89 octane.RacerX said:Sounds like more of a timing problem. You would think there wouldn't be a problem at 9.7 to 1 comp ratio. Mine are closed chamber heads, the engine stops pinging if I add some octane booster with the 93 octane gas, no other changes. Can't remember where my timing is at though. Cam is 290 duration with .509 lift, stock pistons and valve train, heads milled .010. If I remember right, from my early days when I played with engines on a daily basis, you can tweak the timing for more power but at a compromise elsewhere. But that was years ago.
D.Hearne said:I see the dot referred to earlier on about the 4 bbl quench heads having them, I've got a friend thats got 4 sets of quench heads , I'll check them for the dots. Yup those are adjustable pushrods on a non adjustable head. Have you ever pulled one of the fulcrums to see if they're aluminum or iron? I pulled apart a 2 bbl 351C I bought last saturday and it had the aluminum ones. Both the 400's I built for the kid's 77 F100 had iron fulcrums, and the valves were single groove instead of the early 351C's multigroove valves. At least Ford did somethings right in the late 70's in correcting the elcheapo parts they stuck into the non Hi-po Clevelands.
dodgestang said:Another trick to help reduce pinging is to run your pistons at zero deck which optimizes ther quench chamber otherwise it always pings (well mostly anyway) and polish the combustion chambers.
kcp203 said:You can't run 0 deck on a high rpm engine like a cleveland. You need a few hundredths of clearance to allow for rod stretch at higher RPMs. The goal is to achieve maximum quench at redline. Otherwise you can have an unfortunate meeting between the valve and piston.
You want about .035 assembled quench distance (accounting for gasket thickness). Anything over about .060 will have no quench.
Yes I did CC the chambers, I also built the motor myself ( as I do all my engines) With a 400M, using off the shelf pistons, it is impossible to get to a zero deck. Ford made the blocks too tall or the pistons too short. All the 400 and 351C piston's pin heights are too short to acheive a zero deck. A pin height of 1.71 or 1.72 would get you a zero deck on a 400 with stock length rods. But even if you did acheive a zero deck, unless you use quench heads, it'll still ping with the open heads on pump gas.dodgestang said:The dot doesn't mean anything as far as open or closed is concerned.
I've had open chamber with the dot, without the dot, and closed chambers without the dot.
As for your pinging problem...did you CC the chambers to develope your compression calculation? If you haven't you should, here is why...I paid Speedomotive out in CA big bucks for a Stroker kit, I gave them all the specs for the parts I would be using...like the deck height, the cc of the chambers in my heads and the type of heads and put it together without CCing the final product ....I used to run 63cc closed chamber heads...for 400 miles till the motor self destructed....tracking down the problem, Speedomotive faxed the wrong specs to Ross who made the pistons to create 10.5 compression (what I wanted) but with a 78cc open chamber head.....can you guess why it exploded after the dyno tune and running on 93 octane(and those yahoos made me eat the cost of new pistons even though they admitted their mistake)...it also cost me the heads, the block, and another $3500 to recover......never guess on compression.
Another trick to help reduce pinging is to run your pistons at zero deck which optimizes ther quench chamber otherwise it always pings (well mostly anyway) and polish the combustion chambers.
pabear89 said:Had to dig this up again.
Have been looking for the spec's and have not found any pic's of the adjustable push rods.
every manual or pic says or shows adjustable rockers.
Any adjustable rockers i have done is just that, The rocker nuts are where you do the adjusments, eather on the tips or the nut in the center of the rocker arm.
What gives with these adjustable pushrods?
And if they are used for adjusting does this motor have a soild cam?
I went on the Fire relief Cruz sunday and when I was driving near the wall I could hear the tap of lifter noise.
Was going to adjust but don't know if I should set them as solid or hyd for clearence.
Ideas?
PB
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