Block 6695 from an H what kits??

Everyone,

Talk about a big road block. We started with a farmall H that ran but smoked bad. Pulled it apart and someone really honed the cylinders and the sleeves were loose enough to pull out by hand. Purachased another engine, (FROZE UP BUT CHEAP) and it had two broken cylinders. Traded the first block and cash for another that is good out of an H with casting number 6695. This block is good, but the bore is 3.75 (Which equals a 300 Farmall kit).

SO the Major question is (have two dealers fighting over this) Can I run a 300 Farmall Kit (if so with what pistons) in a farmall H with a Farmall H Head? If no, what changes have to be made to make it work? Really want to keep it as close to orginal as possible but if no luck we might start parting the old girl out before we loose our #$$.

Anyway, let us know asap.

When you say it has a 3.75 bore are you talking the block its self? or the sleeve ?

Andrew

The block it self. Standard bore is 3.562 for an H block.

Can you get some better part numbers off it there should be one right above the oil filter thats the one you want. It sounds like you have a Super H/300/350 block. Check that part number again. It will have a list on numbers followed by a letter or two, thats the number you want.

Andrew

6695 is a H block, if the bore is 3.749 or awful close to that the 300 and 350 sleeve kits will work provided they sized the top step in the block to 300 and 350 sleeve size. If not the step on the sleeves can be turned down to fit.
Any flat top piston for a 300 or 350 will work with any H head. If you post the casting # on the head you have with all suffix letters more details may be added. Also if you use the 300 and 350 sleeve set you will probably have to use the special piston pin bushings in the small end of connecting rod. Bushings are sold on this site and other places. Reason being most all 300 and 350 sleeve sets sold now use a .875 piston pin. H, SH, 300 up to engine serial #48048 used 1.109 size piston pins. Later 300 and 350 used the .875 size. IH sold replacement pistons with .875 pins and adapter bushings for all the above tractors. If you can find a set of 300 piston and sleeves with the 1.109 pin size the standard H piston pin bushings can be used.
Webers Tractor Works shows they have a piston set 366356 R91 for $325.00. If I remember that # correct, they are flat top 3-5/8 with the .875 pin. You could ask them by putting a WWW and .com after the name. Depending on the Head or pistons other options will work. With flat tops all you have to match is bore and piston pin sizes.

Another thing to add, if the crankshaft your using is out of a H engine or tractor serial # 391357 or lower you will need to buy the crankshaft bearings and piston,sleeve set separate. If the H crankshaft is from a tractor higher than the above serial #, you may find everything in a complete kit for a 300. I don't know how the aftermarket 300, 350 pistons, most are step head or crater style are on head clearance and H heads. Do know that the IH firecrater pistons they used to sell will hit the head of a H gas head 8043 DC or a lower letter suffix unless massaged.

Tractor Serial Number is FB 355744-x1
Block Castin Number is 6693 (with a 3.75 bore in it)
Head casting number is 8043.

I have been told that this head will not work by the machine shop who talked to the engine kit maker. I am trying to get numbers off of the block that are stamped in, but the block is at the machine shop. IT will take time.

Any help is great.

Suffix letters for the head casting # make a difference. 8043 DD will clear any stock combination of H to 350 pistons. 8043 DC and lower will clear any stock piston for a SH to 350 that doesn't have a step or dome and some that does, but they require checking the clearance. 8043 DC and lower can be tapered on the sharp edge of combustion chamber and gasket surface oppisite spark plug side and work with most raised pistons.

I have a 8043 DC off the old block and a head that is just laying around that should be good that is a 8043 DD. I was hoping to run high dome pistons in it, (firecrater or whatever) Which one should be used? DD? but make sure the clearence is there???

Matt. I know what you mean about the sharp slope of the combustion chamber but want to do this right.

Matt

Can't say about all the aftermarket pistons, but anything sold as a replacement piston for a 300,350 should work with a 8043 DD head, Its very much the same as a 300,350 head combustion chamber. Compression can be kept a little higher with a 8043 DC head and grinding all combustion chambers the same for clearance, with some raised pistons. If not after the last ounce of power out of engine I would just use the 8043 DD.