Cam Choices

[Drew Pojedinec]

They'd tell you to buy a honda.  That is pretty much what they tell everyone with an older car.

On another note, the 429 in my 63.5 Galaxie has a 218 @ .050 duration cam at around .500 lift.
It's a really nice street grind, mean enough to know the engine is there, relaxed enough to idle around in town with no drama. 

[My427stang]

static compression (measured, estimated?), chamber style, head gasket, deck clearance, rod length, bore?

Go too small and you won't be happy with fuel requirements

RJP's is likely a very good cam, very CJ-like, but would like more info to give you an opinion of a specific cam

[ChiefDanGeorge]

I don't have a head gasket yet, looking at that head gasket thread I didn't realize there were so many choices.
The pistons are dish style, heads are the Edlebrok RPM, bore is 4.090.

static compression (measured, estimated?), chamber style, head gasket, deck clearance, rod length, bore?

Go too small and you won't be happy with fuel requirements

RJP's is likely a very good cam, very CJ-like, but would like more info to give you an opinion of a specific cam

[plovett]

I don't have a head gasket yet, looking at that head gasket thread I didn't realize there were so many choices.
The pistons are dish style, heads are the Edlebrok RPM, bore is 4.090.

Do you know the dish volume on the pistons?  Or the part number?

[My427stang]

Dan,

We can get in the ballpark, but what we need is part numbers and some specifics to get really good. 

Piston part number
Crank part number (just want to verify that you have exactly what you expect)
Cylinder head part number
Deck height of the block

The last part is really something you may not be able to give, but if you know deck height, it helps.  If you know if the deck was cut at all, how much would help, and if you never cut it, that would help too, we can likely get close enough with a WAG (although normally we don't like to)

After that we'll start with a Felpro 1020 gasket and go from there with a compression calculation

In the end, again, RJPs cam is likely very close, but the difference between close and real good is where most of the guys here operate.

Hope this was read understanding this is your first build, just need more info in order to do a good job for you

BTW, I may have asked this before too, but is "Chief" in your screen name come from NCO, police officer, fireman or something else?

[plovett]

Ideally we'd like to know the measured cc's of the cylinder head's combustion chamber, too.  The reason I say that is my Edelbrock heads are advertised as have a 72cc chamber, but the actual measured volume is 79cc.  A big difference.  Mine were early Edelbrock head though.  I think later ones are closer to actual advertised volume. 

The first engine I put together with these heads;  I thought the compression ratio was about 10.0:1.  It was actually about 9.3:1 because the chambers were bigger than I thought. 

I'm just echoing Ross's sentiments.  The more info you can supply, the better.

JMO,

paulie

[turbohunter]

After that we'll start with a Felpro 1020 gasket and go from there with a compression calculation

I have to ask. a 4.40 bore gasket with a 4.09 bore?

[ScotiaFE]

My Ed's came in about 76ish cc from the factory and they are about 10 years old.

[My427stang]

After that we'll start with a Felpro 1020 gasket and go from there with a compression calculation

I have to ask. a 4.40 bore gasket with a 4.09 bore?

It's all planning math, just numbers I am familiar with, although it's a good gasket and wouldn't hesitate to use it, the SCE is certainly a better match for the small bore

[ChiefDanGeorge]

I went with the Prison Break stroker kit from Survival.
Scat  9000 Series crank
The pistons are dished for 9.8:1 compression.
Cylinder Head is Edlebrok part #60069
I don't know the deck height.

ChiefDanGeorge comes from the movie Outlaw Josie Wales.

I appreciate all the help!

Dan,

We can get in the ballpark, but what we need is part numbers and some specifics to get really good. 

Piston part number
Crank part number (just want to verify that you have exactly what you expect)
Cylinder head part number
Deck height of the block

The last part is really something you may not be able to give, but if you know deck height, it helps.  If you know if the deck was cut at all, how much would help, and if you never cut it, that would help too, we can likely get close enough with a WAG (although normally we don't like to)

After that we'll start with a Felpro 1020 gasket and go from there with a compression calculation

In the end, again, RJPs cam is likely very close, but the difference between close and real good is where most of the guys here operate.

Hope this was read understanding this is your first build, just need more info in order to do a good job for you

BTW, I may have asked this before too, but is "Chief" in your screen name come from NCO, police officer, fireman or something else?

[ScotiaFE]

Deck Height.
To measure the deck height in the shed.
Put the bearings and crank in the block. Then put a piston and rod in each corner.
Then bring each corner up to TDC and measure the depth from the deck to the piston.
You will need an accurate depth measuring setup.
You will learn a lot about your block and stroker kit from doing this.

[ChiefDanGeorge]

When I get them in, I'll do it.
Is there a particular gauge brand I should get, or is this one of those things worth renting from NAPA since I am not building engines on any sort of regularity?

Deck Height.
To measure the deck height in the shed.
Put the bearings and crank in the block. Then put a piston and rod in each corner.
Then bring each corner up to TDC and measure the depth from the deck to the piston.
You will need an accurate depth measuring setup.
You will learn a lot about your block and stroker kit from doing this.

[ScotiaFE]

The best tool is a depth micrometer.
You can buy one pretty inexpensive on ebay.
You will need a 0 to 1" and you will find that your piston is about 0.010" to 0.020" below
the deck on a stock deck FE.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1311.R1.TR12.TRC2.A0.H0.Xdepth+mi.TRS0&_nkw=depth+micrometer&_sacat=0

[My427stang]

I have beat this drum before, but the best bet is to take the block to the machine shop and tell them what deck height you want.  My hunch is that Barry's setup likes 10.155, but I am not sure without seeing compression height.  If you take the block to the machine shop and tell them, square the decks at 10.160 or 10.155, then you know they are right. 

Measuring in the hole is good for calculating, but if you haven't bored the block, or if the block needs main and deck work, numbers change.

Unfortunately, I still can't provide specifics for a recommendation.  Barry makes a few different kits for the 4.125 crank with different pistons and I have no idea what the compression height and dish size is with his kits.  I can guess though, but it is a guess and should be treated as one.

As an educated WAG....using a 10.160 deck height (ends up .010 below) and a 17cc dish with a 74 cc chamber (assuming Edels are a little big) and a 1020 gasket, you end up at 9.55:1  static.   Seeing these numbers and knowing the difficulty in keeping a 4.25 stroke below 10:1, I can see why he recommended this for your use.

Seeing those numbers, and assuming they are right (big assumption).  You could run as small as a Comp 268H to make some serious torque with decent quench and DCR at 8.02

However, this is all bench racing.  Some of many tweaks in blue printing come from actual deck clearance, actually measuring the heads, having the exact number for the piston dish or d-cup, and choosing the correct gasket to get where you want to be. 

So in the end, looks like you are real close and looks like Barry steered you right.    If it was my first motor, I'd ask Barry, "what should I tell the machinist to cut the decks to?  and "what cam have you had good experience with"     I'll also add if this is your first one, I'd likely go hydraulic roller, and that will likely enjoy slightly more advertised duration, and a little more compression (zero deck and/or thinner or smaller bore head gasket)

[plovett]

It might be a good thing if the Edelbrock's chambers are bigger than advertised in this case.  It depends on how all the parts stack up, but it might be nice to have lower than 9.8:1 compression given the combo.

Picking a cam based on a compression ratio is the backwards way of doing it, in my opinion.  The cam should be picked first, based on other factors, then compression ratio selected or massaged.  I understand that in real life it doesn't always work that neatly.

JMO,

paulie