rmbuilder

Bill,
They warn not to overstretch or reuse pin locks.
The PDf file shows opening them up 1/8"-1/4" only, just enough to begin to "screw" them into the groove.
Bob

Lmarth

Bob- Good to hear from you on such a balmy day(?). Bet you miss the sound of those injected Can Am big blocks! The first floating pin setup in the Mark IV big block was a single pin retainer with a groove around .060"-.062". Heady days when GM moved from 3/8 to 7/16 Boron rod bolts and 'dimple' rods, from closed to open chamber heads and the aluminum ZL-1 block. All this talk about spiral locks is causing my finger tips to ache! Later...Lou

rmbuilder

Bill,
They are made to be slightly stretched. Over stretching and removal reduces the radial tension and makes them prone to failure.
Bob

hpy540

Got the wrong headbolts in the mail today... Good thing Comp products is overnight ups regular rate i am hoping to drop in by the weekend

hpy540

Ok, so we are headed for the first big snowfall of the year. It has not been real cold and I went on my last boat ride about three weeks ago. I put the boat in storage, But now I have the incredible urge to tear it down again. Mid summer I melted down a few pistons and had two other problems. 1 Distributor. 2, oil cooler. I have since solved both of them but now I have some blow by so I would like to freshen it up a little. The brand new dist (that went bad) has really screwed up my motor. Soooooo, this summer I had the opportunity to run DD 2003 number on two friend’s motors. They had actually dynoed. They came out wit in 6 hp on both motors. One was a Dart 540 the other was a warmed up 502. I am somewhere in the 700 hp range before I melted it,(714 at 6000 rpm to be exact) I did hit 94 on gps with about a 2-6 mph current so I would like to get back to that.

So this is what I am thinking about, I am thinking about replacing my intake and I am wondering what to buy? I have hit 5500 rpm and the thing was still climbing when I hit 94 mph gps but I got nervous because we did not have the life vests. An air gap dual plane would definitely bring the torque down a bit in the rpm but I do not know if I need that? I have a Strip Dominator on it now and I know those are junk. I am either thinking Brodix single plane(is this the best for my app) or edelebrock dual plane air gap(is there a better dual plane out there). When I hit 94 it was no fuel and a 236 twin step eliminator eagle with 1.36 gears and worked over 27 mirage prop and perfect conditions, the water was like glass and the temp was about 70 and no humidity 2 people in the boat. It did Chine a little from about 75 to 81 or so but it always settles down after that speed. I did hit 78 mph with 7 full size guys in the boat and ¾ tank of fuel at 5400 rpm and this was it…… it did not have any more left (No Chine either). My average boat load is 4-5 people usually 2 of them are 110 lb’ers and a cooler and fuel. I do not hit the top end runs much but they are fun when I do.

hpy540

contiunued 2nd, since I have at least .140 clearance between the valve and piston I am thinking about going to 1.8 rocker arms. My cam guy has told me that .629 lift with stock GM roller lifters is all I can go with because of the oil band not hitting correctly. The 1.8 would increase that overall lift. Also I am thinking about going to Zero gap top rings, has anyone used these? Do I have to have a special finish when I hone? I also heard it is not good to run zero gaps on all the rings only the top one, I am hoping I do not have to rebore. I think I can get buy with a rehone. The reason I did not go through my 540 completely was the season in WI would have been over by time I did it right. It now has about 37 hours on what were the new parts from last winter. So I am going to gauge the bearings and throw it back together. I am going to take a little squish out of the deck... the SRP's are .018 in the hole and the deck is out of square by .003 on one side and by .005 on the other. With 9.6 CR now... What should I deck it to? The next option is replacing the Gill manifolds with the CMI sport tube headers. This will probably net the most increase in performance.

I feel like there is a crest that when I get past it the boat just keeps on climbing(topping this depends on weight and water conditions). I have yet to really hold it at 6000 and above to see what it tops out at. I have set it up for peak at 6000 to 6200 rpm.

hpy540

continued The next thing is the sea water pump and the lower pulley. The center groove on the lower pulley Is much smaller than the outside ones and I would like to know where I can get a pulley with the same size on all three belts. The next is the pump itself, I think I need to change to a factory Merc Bravo one. Yes I have read the threads on the KPM ones and I do not think I need one of those. I do think I need a slightly larger one like the factory Merc one. I only have slight heat problems when I hold it for over 10 min or so at 4600 or above and the water temps run into the mid 70’s and above. I am also going to put steam bleed offs on the rear water ports of the intake manifold/ head steam pockets.


Recap
Intake: which one?
Rings: zero gap yes or no and what finish
Deck: how much?
Rocker arms: cheap and I am gong to do it any way
Cooling: pump and pulley where to get them reasonably priced
Sport tube’s fred I will be calling.
Overall How much HP or speed should I expect? It has been reliable after I threw it together last time
ANY OTHER SUGGESTINS SINCE I AM GOING THROUGH IT ANY WAY?

Reed Jensen

Spiro locks can be fun if you get the right technique down. The larger the lock the easier... DO NOT STRETCH THEM. Open one half of the lock and stick it over your left thumb.. While holding the piston and rod assembly in your left hand... force the half of the spiro lock that is under your thumb into the lower part of the groove.... then with your right thumb and index finger.. grasp the rest of the lock and twist it in a clockwise manner ( not to rotate the lock, to wind it up smaller)... once you get it started into the groove you can just push it down with your fingers and it will "thread" itself in. Good luck... It took me several engines before I mastered this technique. BUT IT WORKS GREAT ONCE YOU FIGURE IT OUT!