I started this post in the Evo Classic section but thought there would be some motor enthusiast over here that would be interested...

After my second mishap with cranks I'm hoping this will be my last build for this motor. I won't be changing or modifying this build again and am confident it will last for a long long time.

I just picked up my motor yesterday from Hillside. Thanx Scott for taking time out of your personal time and meeting me on a Sunday to help me out. It was nice chatting with you again... Greatly appreciated. 600 miles round trip in 17 hours so I'm a little dopey today.

Anyways, started assembling the oil pump lines and filter mount. Lined up the motor to the trans with my Baker primary motor plate and got it all snugged down so the alignment is done. Tonight I'll be assembling the primary drive, charging system and starter. Once that's done I'll start assembling the rear head and adjust the pushrods setting the preload to .140" . Once that is done I'll be able to confirm my target compression of 10.3:1. (43* ivc). Special Cam I had Bob Wood grind for me...

J&E are the only piston manufacturer that could supply me with what I needed to get the motor up to 10.3:1. They are 30* angle top's and are .020" over bore putting the cylinder bore at 3.645". Couple that with my S&S 4 5/8” crank it's putting the displacement right at 96.5 cubic inches.... I'm pretty fortunate that the Cometic head gasket was just barley big enough for my bore....




For the heads, I had Scott supply me with a new set of heads that he worked up to stage III. A lot of the D shelf was remove to accommodate the 1.94" intake valve and a 1.65" exhaust. If you look closely you can see how the D shelf was also dished out for the Piston as well. With all the machining to the heads, the combustion chambers are now very big requiring the use of the 30* angle to pistons to get me to my target compression...








I didn't realize all the work that had to go into the heads to accommodate the 30* piston dome. Not only that, another thing I noticed was the small chamber around the entire combustion chamber, Scott said it was necessary and is precisely measured to get the proper combustion chamber size and will also aide in the fuel burn efficiency... and yes I did have compression releases installed... oh yes forgot to mention the AV&V valves and springs good to .650" of lift...

Check out the intake and exhaust ports, man this motor is going to breath well. He initially qouted 278 CFM... Not bad for a small block, eh?








I must say I'm really impressed with his work and am sure I'll be just as impressed with the power

I almost forgot to mention why I went this far with this build is because the left case main bearing sleeve was trashed due to a bad crank that was installed else where. Scott took care of the as well. He machined his own sleeve and mechanically fastened it to the case. Bullet proof now... I'm sure. Here's a couple pics of that as well..





That's about it for now I will update my progress as it goes....

Thanx again Scott.....

 

Looks good. Should be a runner.

 

Very cool. I don't have intimate knowledge of Evo's but it looks like a lot of custom stuff going on. I don't see a lot of domed pistons in the TC builds I read about.

 

Yea, with the size of the bore on them now you don't need domes. Thanx hope it will be up and running soon...

Last night as I was putting it back together I didn't need to shim the rotor on the alternator. With the new sleeve that Scott made it gave me the perfect clearance I needed... Quality machining there....

And as he would say "Not made in China"................

 

Looks impressive.. Sounds like a it'l be a strong motor.. Intake a 1.94 valve?

 

Yes. Should breath well... Thanx....

This morning I was looking at the Cam that came out and noticed abnormal wear on the journal on the bushing end of the Cam. One side of the journal showed wear marks with the bushing and the other side looked new.

I guess that there would confirm excessive run out on the crank.

 

Thanks for the kind words Bob.
More to these set-ups than some folks may suspect.
Scott

 

So with the Evo's you can't typically get the bore big enough to hit your target compression? Necessitating the domed pistons?

 

With valve seat replacement, larger valves, chamber blending to un-shroud,
the chamber volume requires a domed piston, to keep from re-surfacing the heads and creating issues that can be avoided.
Scott

 

Sorry Scott did not see your post......


Technically it's about the heads and totally dependant on the combustion chamber size. I wanted to go with stage III heads for this build. So to accommodate for bigger valves, the combustion chambers had to be opened up way above a stock chamber size. That alone dramatically decreased the static compression and the only way to get it to target compression was with the use of domed pistons.

The thing that really sucks is that there is no real demand for my type of build so the availability of the proper piston is very limited. I believe Scott stated that JE was my only option for a piston in the 3 5/8" bore.