MR and Tunnelport Castings - Update!

[mbrunson427]

This week was a big week for us. The set of test castings were produced and are now ready for final machining. From initial inspection, only a few minor details need to be changed to the casting cores for the production version. Once machining is complete, we'll be able to give final feedback to the foundry.

For anybody on the forum that has followed along in any capacity, I know this has been a long journey. We're staying persistent with it. Now that we have castings in-hand the updates should come much more frequently!

[feadam]

Is this going to be a copy of original or new style chamber and improved ports?

[e philpott]

looks like a nice casting

[mbrunson427]

Is this going to be a copy of original or new style chamber and improved ports?

There's a little bit of information here:
https://brunsonperformance.com/products/heads/

Basically, taking stock architecture, stock intake manifold location, stock exhaust location, stock valvetrain, and trying to maximize everything else.

[475fetoploader]

    curious about bolt holes, like exhaust etc.  Helicoiled? They look great.  Happy about more options for fe heads.

[GerryP]

That MR Interceptor could make TF's production issues irrelevant.

[Gregwill16]

They look great! I went to the link but didn’t see anything on the intended bore size. Do they have the MR valve spacing? Will they work on 390 and 428 bores or 427 only?

[mbrunson427]

They look great! I went to the link but didn’t see anything on the intended bore size. Do they have the MR valve spacing? Will they work on 390 and 428 bores or 427 only?

427 and 428 bores they clear easily, 390 will clear but there may be a lift limitation. This is going to be one of the first things we check once the heads are ready to bolt on a block.

In an FE the valves do not travel straight down the centerline of the bore, they move towards the cylinder wall as they go down. So we need to see how much lift can be had without getting too close to the wall for comfort. We have run the simulation in the computer.....but need to see it on a block.

The TP heads were not designed to fit in a 390 bore.

[Gregwill16]

Okay thanks. I tried MR heads on a 4.16” bore and the exhaust valve was touching the wall above .600” lift. But that was with the normal 1.73” MR exhaust valve. I am not sure how much clearance is needed to not have any shrouding issues though.

[feadam]

Do you have timeline of when you think these will be released for sale

[blykins]

If they go into steady production, I'll order multiple sets of custom pistons for different bore sizes to have them on hand.   That big fat intake valve will pose a problem with a lot of shelf piston valve reliefs. 

[jbamber]

"curious about bolt holes, like exhaust etc.  Helicoiled?"

All tapped holes (except valve cover bolt holes and sparkplugs) will have thread inserts (not helicoils).

"Do you have timeline of when you think these will be released for sale"

Assuming we don't find issues with the "first articles", shipping could begin as early as late November.  We may start taking orders once we have approved the first articles and released production at the foundry.  You can expect regular updates.

[475fetoploader]

 Christmas time! Woohoo

[Riderjeff]

Christmas is getting close, is Santa coming?

[DuckRyder]

Ill have to go back and read up on these...

Looks pretty interesting.

Guess those buying know bit are there tunnel port intakes out there...