Another 400 build.
Cargo Master
Joined: Oct 2020
Posts: 2,657
Likes: 776
Who knows where the stock 400 pistons really sit in a typical engine they probably are that far down especially if you're using a rebuilder piston. I was just thinking that there are probably a lot more performance orientated pistons for the 351C than the 400 and those will probably have a taller compression height. 1.653 is what the KB Icon catalog shows for a 351C piston. If you look up a Sealed Power 427P rebuilder piston for a 400 it shows 1.630. That's a heck of a difference right there.
4wd Low
Joined: Mar 2018
Posts: 10
Likes: 0
From: IL
I don't understand what you think is wrong with Tim's pistons. When he used to build engines, I think I remember him using Trick Flow heads if that is what the customer wanted. Track Boss Products – Piston & Ring Set – Ford 400 (tmeyerinc.com)
Laughing Gas
Joined: Dec 2020
Posts: 869
Likes: 186
From: Near my truck
Those DSS pistons look to be spot on. 
The 1.71 is correct, and the 13cc will make your static +/- 9.8 which is very acceptable.
Maybe ask them for their comments with regard to matching their pistons with your proposed build etc.
Maybe see if you can find user reviews on their pistons too. (I haven't heard of DSS, not that that matters.)
@ dmash : There's nothing wrong with the pistons in your link. However, they are suited to open chamber heads. TM used to offer KB pistons similar to the above DSS pistons which are suited to closed chamber heads.
The 1.71 is correct, and the 13cc will make your static +/- 9.8 which is very acceptable.
Maybe ask them for their comments with regard to matching their pistons with your proposed build etc.
Maybe see if you can find user reviews on their pistons too. (I haven't heard of DSS, not that that matters.)
@ dmash : There's nothing wrong with the pistons in your link. However, they are suited to open chamber heads. TM used to offer KB pistons similar to the above DSS pistons which are suited to closed chamber heads.
Cargo Master
Joined: Oct 2020
Posts: 2,657
Likes: 776
I don't understand what you think is wrong with Tim's pistons. When he used to build engines, I think I remember him using Trick Flow heads if that is what the customer wanted. Track Boss Products – Piston & Ring Set – Ford 400 (tmeyerinc.com)
Cross-Country
Joined: Jan 2018
Posts: 63
Likes: 9
I know this is a little bit older thread but I just wanted to give a source for pistons.
I found an outfit in Orem, Utah called "Clegg Engine and Machine" that custom made forged flat-top pistons for my 400 to get me exactly the compression ratio I needed. (needed about 9.3:1 SCR) They were actually very pleasant to work with and as I recall, the price of the set was right around $600.......which I realize is quite a bit compared to off-the-shelf stock pieces but since raising the compression on these old things seems to give the most "bang for the buck" and having limited selection....... I didn't think it was outlandish.
They said they shipped about 10 sets of forged Ford 400 pistons per month.
I found an outfit in Orem, Utah called "Clegg Engine and Machine" that custom made forged flat-top pistons for my 400 to get me exactly the compression ratio I needed. (needed about 9.3:1 SCR) They were actually very pleasant to work with and as I recall, the price of the set was right around $600.......which I realize is quite a bit compared to off-the-shelf stock pieces but since raising the compression on these old things seems to give the most "bang for the buck" and having limited selection....... I didn't think it was outlandish.
They said they shipped about 10 sets of forged Ford 400 pistons per month.
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More Turbo
Joined: Nov 2018
Posts: 563
Likes: 143
From: CA
Thank ya. I haven’t torn down yet, so have yet to pick up pistons. Will keep em on the radar.
picked up trick flow heads 72cc, scorpion rollers. I think a cam is the last pre tear down thing I can grab, at least for big ticket.
picked up trick flow heads 72cc, scorpion rollers. I think a cam is the last pre tear down thing I can grab, at least for big ticket.
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More Turbo
Joined: Nov 2018
Posts: 563
Likes: 143
From: CA
No big news got a cam selected. Went with Howard’s with their link bar lifters. Eric at Howard’s was great to deal with, only outfit that answers emails and promptly even. Was tryin to get comp to do a grind similar to xe262h in a roller profile, no response from anyone after multiple emails(same with the whole family comp, crane, lunati). Hopefully that and the intake I ordered in March will show up around the same time and I’ll tear down. Intakes latest ship update is March.
Had a couple leaking freeze plugs and cracked exhaust manifold so now have some hedman fenderwell exits and am waiting for magnaflows to show up to build the exhaust, going stainless 2.5 dump in front of rear wheel.
Engine:
351C, 351M, 400
Camshaft Type:
Hydraulic Roller
Basic RPM Range:
1600 to 5600
Valve Lift Intake:
.571
Valve Lift Exhaust:
.577
Duration Intake:
270
Duration Exhaust:
278
Duration at 050 Intake:
217
Duration at 050 Exhaust:
225
Lobe Separation:
110
Intake Centerline:
106
Firing Order:
1-3-7-2-6-5-4-8
Had a couple leaking freeze plugs and cracked exhaust manifold so now have some hedman fenderwell exits and am waiting for magnaflows to show up to build the exhaust, going stainless 2.5 dump in front of rear wheel.
CL233215-10 grind
Engine:351C, 351M, 400
Camshaft Type:
Hydraulic Roller
Basic RPM Range:
1600 to 5600
Valve Lift Intake:
.571
Valve Lift Exhaust:
.577
Duration Intake:
270
Duration Exhaust:
278
Duration at 050 Intake:
217
Duration at 050 Exhaust:
225
Lobe Separation:
110
Intake Centerline:
106
Firing Order:
1-3-7-2-6-5-4-8
98445-K12 springs
- OD: 1.470 in.
- ID: .800 in.
- Seat Load: 120 lbs. at 1.875 in.
- Open Load: 425 lbs. at 1.110 in.
- Coil Bind Height: 1.080 in.
- Rate: 399 lbs
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Thread Starter
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More Turbo
Joined: Nov 2018
Posts: 563
Likes: 143
From: CA
Starting to doubt this cam choice. Looks like at 9.5 static it would be 8.5-9 dcr depending on the calculator I use.
seems like increasing duration lowers dcr but also moves rpm range higher.
this is a big heavy truck, looking for torque down low not top speed. 87 preferred, 91 is the max for pump around here, I spend a bit of time where there’s only 87 but can probably manage with capacity.
seems like increasing duration lowers dcr but also moves rpm range higher.
this is a big heavy truck, looking for torque down low not top speed. 87 preferred, 91 is the max for pump around here, I spend a bit of time where there’s only 87 but can probably manage with capacity.
Laughing Gas
Joined: Dec 2020
Posts: 869
Likes: 186
From: Near my truck
The duration numbers do not lower, or raise, the DCR, only the Intake valve closing (IVC) time does that.
The 0.50 durations generally determine the rpm range.
For example, 217/225 starts the rpm range at 1,600, but 207/215 might start at 1,000 rpms.
Are you using an IVC of 61* in your DCR calculations ?
The 0.50 durations generally determine the rpm range.
For example, 217/225 starts the rpm range at 1,600, but 207/215 might start at 1,000 rpms.
Are you using an IVC of 61* in your DCR calculations ?
Cargo Master
Joined: Oct 2020
Posts: 2,657
Likes: 776
That cam choice is extremely poor if you want to haul a big heavy truck and need torque just off idle. You would be much better off with a lower compression ratio, shorter duration, single pattern and a tighter lobe separation. The only thing that changes dynamic compression is the intake valve closing event. Make it earlier and the compression stroke is longer, make it later and the compression stroke is shorter. Longer duration and or a higher intake centerline moves the intake closing point later.
Laughing Gas
Joined: Dec 2020
Posts: 869
Likes: 186
From: Near my truck
Using an IVC of 61* and the calculator below, it shows a DCR of 7.8 based on a 9.5 SCR.
Wallace Racing: Dynamic Compression Ratio Calculator
(The 61* is based on the 0.006'' lift)
Wallace Racing: Dynamic Compression Ratio Calculator
(The 61* is based on the 0.006'' lift)
Thread Starter
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More Turbo
Joined: Nov 2018
Posts: 563
Likes: 143
From: CA
Using an IVC of 61* and the calculator below, it shows a DCR of 7.8 based on a 9.5 SCR.
Wallace Racing: Dynamic Compression Ratio Calculator
(The 61* is based on the 0.006'' lift)
Wallace Racing: Dynamic Compression Ratio Calculator
(The 61* is based on the 0.006'' lift)
I came up with 34.5 ivc?
https://www.gofastmath.com/Compression-Ratio-Calculators/Camshaft-Valve-Timing-Degrees-Calculator
Laughing Gas
Joined: Dec 2020
Posts: 869
Likes: 186
From: Near my truck
Your 34.5* number is correct, but at the 0.05'' timing.
The DCR calculator will think that the intake valve is actually closed at 34.5*, but in reality, the valve would still be open at that time.
0.006'' is still open, but is a lot closer to 0.00'', which is fully closed.
Use the advertised 0.006'' durations, and you'll get an IVC of 61* and a DCR of 7.8.
Then you can relax !!! LOL
The DCR calculator will think that the intake valve is actually closed at 34.5*, but in reality, the valve would still be open at that time.
0.006'' is still open, but is a lot closer to 0.00'', which is fully closed.
Use the advertised 0.006'' durations, and you'll get an IVC of 61* and a DCR of 7.8.
Then you can relax !!! LOL
Thread Starter
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More Turbo
Joined: Nov 2018
Posts: 563
Likes: 143
From: CA
Your 34.5* number is correct, but at the 0.05'' timing.
The DCR calculator will think that the intake valve is actually closed at 34.5*, but in reality, the valve would still be open at that time.
0.006'' is still open, but is a lot closer to 0.00'', which is fully closed.
Use the advertised 0.006'' durations, and you'll get an IVC of 61* and a DCR of 7.8.
Then you can relax !!! LOL
The DCR calculator will think that the intake valve is actually closed at 34.5*, but in reality, the valve would still be open at that time.
0.006'' is still open, but is a lot closer to 0.00'', which is fully closed.
Use the advertised 0.006'' durations, and you'll get an IVC of 61* and a DCR of 7.8.
Then you can relax !!! LOL