Cam for 440 street build

[TrackPack]

First thing is lose the pistons and build a quench motor, I did and its a beast. 915 heads ported/polished, light weight JE/SRP pistons, Mopar .528 Mech Cam, 6 pack setup, perfect .040 quench with .020. steel shim gasket. 520 HP on pump gas with dyno headers.

I'm guessing that's a bit over 10.5:1 with the 915's. Does that cam duration/overlap bleed off a bunch of compression?

 

[68-500]

That would work, but I think the block deck and heads would have to be surfaced for the mls gasket.

Here’s what I wonder about; if a uncoated steel shim gasket can seal deck to cylinder head with factory machined surface. Why can’t a coated with some fancy sealer mls gasket can’t do the same?

 

[1968rt]

I'm guessing that's a bit over 10.5:1 with the 915's. Does that cam duration/overlap bleed off a bunch of compression?

I calculated compression at 10.2, the chambers were cleaned up a bit and came in at 81cc. With normal lash .028 and .032 the cam doesnt bleed off much. Im running the lash tight at .018 and .022 which helps a bit

 

[TrackPack]

Here’s what I wonder about; if a uncoated steel shim gasket can seal deck to cylinder head with factory machined surface. Why can’t a coated with some fancy sealer mls gasket can’t do the same?

Good question. I know that Cometic wants a specific smooth finish for some reason. We used to use copper coat or sometimes silver paint on the steel shim type.

 

[TrackPack]

Is Racer Brown still open for business? I'm thinking of contacting them for some advice.

 

[RemCharger]

Good question. I know that Cometic wants a specific smooth finish for some reason. We used to use copper coat or sometimes silver paint on the steel shim type.

Exactly, the steel shims were supposed to be used with a sealant. When we were doing the neon headgaskets, the TSB also called for the Mopar gasket spray on the new MLS gaskets.

 

[lewtot184]

I believe the correct way to use a camshaft to bleed cylinder pressure is to use a solid lifter lobe profile with an asymetrical lobe. The LSA is a factor also. Just adding duration by itself may not be the answer.

 

[PRHeads]

Is Racer Brown still open for business? I'm thinking of contacting them for some advice.

Still comes up no problem on a google search.

 

[1968rt]

FBO Ignition - Home of the HRR688 - Racer Brown Cams

 

[Dodge Bros]

The mechanical cams listed in the first post are very tiny cams for a 3000 stall and 3.55s or 4.10s in a 440. Definitely would want the bigger of the two if you want the most out the the combo. They are both smaller and would idle smoother than a XE274 HFT (230/236 but is a hydrualic). You have to deduct the lash off the .050” durations to compare them to a HFT, plus the lash comes off of the max lift. The 230/236 SFT would slightly smaller than an XE268 with a baby smooth idle. The lash takes off around 8-10* of duration from the .050” rating on those profiles. An old .528” SFT Mopar performance cam out run those cams everywhere.

 

[BSB67]

…….The lash takes off around 8-10* of duration from the .050” rating on those profiles.

When comparing any solid cam to hydraulic cam, generally speaking.

 

[Dodge Bros]

Just throwing this out there - but has anyone successfully used a low lift hydraulic roller cam with solid roller lifters on a combo like mine? I had ruled it out because of expense, but flat tappet lifters seem to be a real problem these days.There is no reason you could not do something with less lift. Not every HR profile works well with SR lifters, you have to keep in mind how much the engine expands.

We do that frequently.

Something like a comp extreme marine 236/244 would be about .540” ish lift range with a 1.5 rocker. You can more or less do what ever lift you want on the low side. The cam needs more seat timing than most off the self HR cams to work well. Otherwise the lash window gets to be small.