Hello,

I posted this over at hotrodders and not a lot of feedback.

Has anyone had success with trick flow heads on a stock 400 short block? Mine is a 78. I think the piston is ~.070 in the hole.

Did the increased compression cause more detonation? My short block is in great shape and does not need a rebuild. I am considering a new set of Tmyer pistons.
I know there are 100s of combinations, but if you are running TFs on a stock short block,, please share.
This motor does not need to be a monster,, just solid on pump gas.

Thanks,
Jon

 

Don't have any experience with them myself, so am interested to hear what others have to say about it.
Any reason you are asking about the Trick Flow heads only, as opposed to the Edelbrock or any others?

I would try it myself, and am still contemplating the Edelbrock heads even though I've had my stock heads refurbished already. I don't think the slightly higher compression would be as big a deal with aluminum heads as it would be with stock ones. In theory at least the combustion chambers are a better, more modern design and should afford a slight added resistance. i don't know that for a fact, but it seems like that would be the case.
All the more reason for me to listen in on anything that others have to say.

Good luck. Hope you get lots of feedback.

paul

 

TF heads, or Edelbrocks for that matter, would work fine, assuming that the valve spring pressures and springs match the cam.

To me that's a 'half job'.

Seeing as you're considering pistons, then it sounds like you'd be prepared to do a 'complete job', which is what I would recommend.

This is what I would do :

Measure the deck clearance on every single cylinder. (I'll assume for now that they are all 0.70)

Measure the compression height on a piston. (If OE, it should be 1.65)

Assuming it is 1.65, then you'd want a piston set with a compression height of 2.35 (1.65 + 0.70).

That would give the engine a deck clearance of 0.00 (a.k.a. zero deck) which is exactly what you want.

A negative deck height of up to 0.006 would be fine.

Assuming a zero deck can be achieved, check the cylinder head cc's that TF offer, as there are several, and check the 'new' piston dish top or recess cc's.

With those numbers the static compression ratio can be accurately estimated, and you want to aim for between 10 : 1 and 10.5 : 1.

Once you've worked out the static, the camshaft ''intake valve closing advertised at 0.006 time'' needs to be guessed to give a dynamic compression ratio of between 7.5 and 8.

Once that is determined, a cam can be safely chosen. (Roller or flat tappet)

The cam manufacturer should specify what springs and spring pressures will best suit their cam.

Those numbers can be checked against a TF assembled head.

If need be, an un-assembled head can be obtained instead.

The valve train may need some changes to it. E.G. Moving to roller rockers.

Next up is a change in spark plug, dropping 1 range cooler for every 1 increase in static.

So, with a decent ''quench'' and a decent ''squish'', the engine will be detonation free on pump gas, will be more powerful, and will get a gas saving of about 10%.

The mechanical ignition timing will need to drop from +/- 34 total to +/- 24 total, and this will reflect the far more efficient engine.

Hopefully you find value in this feedback.

 

The TM pistons are the way to go for sure. I run 11.3 in a Dart 406 (AFR) and 11.8 in my AMC (Edlebrock), both on 91 octane with zero issues. I run zero deck height on both of those build and a ~.039 gasket. Tight enough there is no room for combustion between the piston and head.

 

Good info TY

 

Old thread,,,,,,, I wanted to update,,, I would not use the TM pistons again or recommend them,,, Bad Quench design. I would choose D.S.S. FX-Series

https://www.summitracing.com/parts/d...4040/make/ford

https://dssracing.com/search?q=1-397...t&type=product

 

Are you having issues with the TM pistons or just simply found a better design after the fact?

 

The TM piston is a stepped design,,, the website pictures are easily misleading. The only portion of the piston that is a zero deck height is very small, the rest of the piston is deep in the hole not much different than the OEM. During Covid i could not get a decent piston made. I realized a 302 piston is close with a little machine work. Researching that I discovered the DSS. They started making these right about the time i was building my motor..

I am not having insurmountable problems but with the quench area i feel i can add optimum timing to the motor. I am adding a AFR and vac gauge now and will dial it in this spring. The motor is insanely strong but feel it could use more timing and sooner, but detonation is occurring. My other high compression for pump gas motors are true flat top pistons ~.005 in the hole the a .035 gasket. The Head CC dictates the compression...They have no problem on 91 octane.

Chris

Here is my build thread for the 400

https://www.ford-trucks.com/forums/1...r-pistons.html