OST-062: Mixed Breed Autocross Whip

[oldeskewltoy]

not a huge fan of 2nd gen largeport heads....... the flaws in this one are(were) pretty bad....




The 2nd gen castings don't seem to have the same port alignment as the earlier heads.... not saying that all the early heads are good... just that the later gen seems to have more "bad" ones....



more to come.......

[oldeskewltoy]

a more familiar view.....

1 down... 3 to go.....




more to come....

[oldeskewltoy]

When I disassembled this engine, I had a real rough time removing the rear exhaust side head bolt. Once "broken" loose... it wasn't loose, it required me using the ratchet AND lifting the head at the same time to get the bolt free from the block. Once the head was free, the bolt had to be "gently" hammered free of the head using a drift. That head bolt may(likely) will need to be replaced. Special attention is being paid to making sure the threads inside are clean, and true



So, the blocks surface back in that area is significantly "damaged", and a healthy block decking is in order to get the block true. Anticipate as much as .012" to be removed...........




more to come......

[oldeskewltoy]

from another forum Wrote:That .012" might work well enough. I found a lot, if not most, aftermarket pistons are machined for a .010" lower compression height. That's for a good clean up on the block.

We shall see.... Cometic has soo many different thicknesses, it should be no problem setting squish between .032", and .036"


Further progress on the head.... 2 down......

intake....




exhaust....




Chambers....






Working short radius for #4 intake valve






before and after (apologies for fuzzy after pic) both bowls ported, and chamber deshrouded





more to come.....

[oldeskewltoy]

from another forum Wrote:Looking at that engine compartment again. Is there a reason for using a turbo manifold?? Clearance issues? Wouldn't a stock Corolla mani do a better job?

I BELIEVE a tube header can be made, but nothing available will fit. The Datsun uses a worm and roller type steering, and the steering arms (pitman arm, tie rod sections, and center link) interfere with anything off the shelf. While not desirable, this seems to "work".



3 down..........

intake...




exhaust...





and chambers......






more to come.....

[oldeskewltoy]

from another forum Wrote:Maybe a FWD mani would do better, with the way turns back into the block would give the clearance to the steering box. At least it would have a better blended exhaust flow and remove a 180* bend. Fabbibg the downpipe would give a chance to tune the exhaust a bit as well. Just need a mani and downpipe flange.
Wish I could find an old car like that. Buddy has a Mango I've been trying to talk him out of.

I friend (whom passed away about 4 years ago) had a Datsun 1200 coupe with a 4AGE and a "proper" header... he had to have it built... and then some of the primaries were longer then others.... All the existing exhaust manifolds just don't fit.

4 chambers deshrouded





4 intakes....




and 4 exhausts....





Its off to the machine shop for a fresh 3 angle, back cut the intake valves, and machine the surface .010"



more to come.......

[oldeskewltoy]

from another forum Wrote:OST just out of curiosity how far can you deck a 4age block?

To be honest... I have no idea... I'm sure you can take as much as .020", maybe more. How thick is the thickest gasket??? Cometic has a .120" thick gasket.....?????


I've been told the block only needed .009" to get that area perfect again..... photo below shows corresponding bad area in head.




more to come......

[oldeskewltoy]

More to come.... soon.


I've finally gotten the major components back, the remanufactured short block with .003" piston down from the deck




as well as the head - ready for assembly




more to come.......

[oldeskewltoy]

from another forum Wrote:The DNJ pistons have worked out well for people's builds?

This is the second engine I've built that utilizes those pistons. OST-032, Skippy... that engine was also built using the DNJ pistons, Skippy's engine is now being used in a FX16 built for rally use.