69 Z/28 Day II Project (Air Force Brat)

[rszmjt]

[QUOTE=NorCam;1532725]Been there...done that. The problem with DHC heads is that they will not accommodate the large diameter 1.550 springs needed for this roller cam. The top guy at Trick Flow (forgot his name) warned me not to try and cut them. Max spring pocket on the Trick Flows is 1.470 and they are best suited to hydraulic roller cams or smaller solid lifter cams.


FWIW. - 186 heads can not be safely machined for 1.550 springs either, the end spring pockets are prone to hit water, you can step cut them with a .060 stock diameter shim in place and then use .100 long valves, but this may mess up the rocker geometry.

Plus you will probably lose 40+ HP.

Maybe you could find a Orphan Tarantula Intake manifold ( or period correct ) and have the tops of the intake runners Tig Welded up/ground down, to work with your current heads?.

[NorCam]

Hi Mike,

I still recall what you taught me about the big cams vs. cutting springs into the stock castings and what the limitations were. If I find the right set of 186 heads I was planning to pull the solid roller and swap in a mechanical cam that's a little more forgiving on the valve train.

Have you got a set?

I'd really like to mount up the stock intake but need something a little more stock...ish.

[rszmjt]

Sorry, I Don't have any nice 186,s rite now. All the heads I have would require a lot of work, inserts/studs/ etc. just orphan heads that are hurt. I know you are going to "lean" on it so a nice set is in order.

Jason - SuperNovaSS said he has a nice set of bare "492" angle plug heads, those already have screw in studs & guide Plates. and those would be period correct for your day 2 look, and have the same end casting symbols as a "186".

I even had a set of those on my own Z about 1975, when you could buy them from GM for $80 a head bare. Then just buy valves/springs and assemble them. Great cylinder head BTW.

[big gear head]

The only problem that I've run into with the angle plug heads is header clearance with the plug wires. Some headers work with them and others don't.

[NorCam]

Yup.

And the m/t headers I had made for this motor were not setup for angle plug heads. Unless a set of dated 186 heads appear real soon, I'm going to bolt the Vic Jr intake back onto this engine and put it into the car for the upcoming season.

I have to wait until spring to finalize a deal on the DZ motor I have lined up and I'm pretty sure he said he has the matching heads for the block as well. That can sort itself out later and then I can build that one and take my time building it right.

Back on task here...

[SuperNovaSS]

I would also make you a deal on these:

https://www.ebay.com/itm/353358285652

https://www.ebay.com/itm/353358294755

The both came off the same good running engine.


Jason

[Scott69Z]

Originally Posted by NorCam

Yup.

And the m/t headers I had made for this motor were not setup for angle plug heads. Unless a set of dated 186 heads appear real soon, I'm going to bolt the Vic Jr intake back onto this engine and put it into the car for the upcoming season.

I have to wait until spring to finalize a deal on the DZ motor I have lined up and I'm pretty sure he said he has the matching heads for the block as well. That can sort itself out later and then I can build that one and take my time building it right.

Back on task here...

What about running the trick flow double hump heads? I saw you did this on a previous build. Were you happy with those heads? I was thinking of using those heads on a block I have to build a look a like 302 for my Z. I don’t see too many people using them. Your build looks amazing. Look forward to the daily progress.

Scott

[NorCam]

Hello Scott,

I really liked the Trick Flow heads on the 383 I built for the Nova but as mentioned above they are limited on spring pocket size. That rules out using those with this cam. If I were to pull this motor down and swap the cam out they would make a viable option but considering all the work done to this motor that would be an unwise decision today. I do have some 1206 intake gaskets here so tonight I will set the intake back in place and move along using this engine for the time being. I really need to get my hands on the DZ block I want and build something a little more period correct for this car. That being said I need to be patient. It will happen soon enough...

Thanks for chiming in and thank you for the kind words.

[RALLY]

i say use the stock rpm tach. classic. doing a great job on your z.

[NorCam]

Scored a good set of February dated 186 heads this afternoon through this great forum. Once they arrive I'll go through the heads and will prep them for a modified DZ engine build.