1973 Mach 1 Engine Build - Machine Work Done!!

[Sparky]

I looked at the heads that had been messed with using the crane roller rocker and small to big stud kit and decided against using it. I found a 1970 set of small chamber heads with chambers between 62 and 63 cc's - see before pics. I had them planed and cut for studs and guide plates as well as fitted with bronze guides, Manly stainless valves and hardened seats. Chambers are probably below 62 cc's after machining. Bottom end left alone with L2379 flat tops and 4 bolt bottom end (less than 6k miles). Now the real work begins with the head swap and cam swap. Comp Cams roller rockers and lifters with the bullet cam and a new Holley DP. Has anyone advanced their cam a couple degrees for an around town only build? Thanks

 

[Sheriff41]

72 and later 351C used a timing chain set that was 4° retarded. Common practice was to replace the timing chain set with one for a 70/71 351C. A couple extra degrees should be manageable for the street and provide some improved low end performance, but with a new cam I'd want to try it straight up first and see how it performs.

 

[c9zx]

What gear, what transmission, if auto what stall convertor? Given the cam specs, I'd degree the cam in straight up. I also suggest calculating static and dynamic compression ratios. You can use the Diamond piston calculator for static and the Wallace Racing calculator for dynamic. Good luck with the build. Chuck

 

[Sparky]

What gear, what transmission, if auto what stall convertor? Given the cam specs, I'd degree the cam in straight up. I also suggest calculating static and dynamic compression ratios. You can use the Diamond piston calculator for static and the Wallace Racing calculator for dynamic. Good luck with the build. Chuck

Hi I used the compression calculator online from Summit and got 11.2 to 1 with my specs. C6 auto trans and converter is yet to be determined. Probably 3000 but will fire the motor and then check idle characteristics etc. Thanks

 

[Q1SVT]

Sparky... did you have Bulet spec your cam?
I have a Bullet very close to yours for a 2V aussie build . yours should be very torquey but a 4V needs some RPM...

As stated by others with your compression may need to retard it [advancing the cam timing can increase compression] My 4V has the same 70 CC heads with a lot of cam and dynamic compression nearing 8.4-8.5 [street driving]

With the C6 you'll want about a 3000 rated converter, but should break about 2700 with your cam
Need to run a C6 Servo Piston "R" Ratio ... I like Sonnax brand

 

[Sparky]

Well fate has smiled and I now have a 410 cubic inch bottom end. Full Scat crank and rods, have the Dyno sheet at 650 HP. Need to decide if I should use the solid roller cam in place or use my bullet hydraulic roller? Engine has only dyno hours but has sat for 6 years. Checking bottom end this week.
Looking for gaskets to put the 410 together - have Fel Pro head gaskets but cannot find intake gaskets/ Suggestions?

 

[Sparky]

Sparky... did you have Bulet spec your cam?
I have a Bullet very close to yours for a 2V aussie build . yours should be very torquey but a 4V needs some RPM...

As stated by others with your compression may need to retard it [advancing the cam timing can increase compression] My 4V has the same 70 CC heads with a lot of cam and dynamic compression nearing 8.4-8.5 [street driving]

With the C6 you'll want about a 3000 rated converter, but should break about 2700 with your cam
Need to run a C6 Servo Piston "R" Ratio ... I like Sonnax brand

Hi - now have a new bottom end so full tranny build will be needed to handle 650 HP - 3000 stall for sure!

 

[Spike Morelli]

Quite a few camshaft manufacturers actually have 4 degrees advance right into their cams as you get them, and is common. Comp comes to mind, and Comp's data sheet will tell you to their cams are designed to be installed 4 degrees advanced. Doing so hurts nothing and will initially give you a tad more bottom end. If you are running a timing chain, as opposed to a belt drive or gear drive, as the overwhelming majority of us are, the chain will develop some slack during use. This is normal, and will retard the cam timing a scosche, so advancing the cam from the start, in effect, will allow the cam to retard into "straight up" as the engine gets some miles put on it. To set the timing set "straight up", or, "dot to dot" from the start is fine too. Most people don't have the things necessary to degree-in a cam anyway, and you'll likely not notice any difference, I mean, it's a brand new build, it's gonna feel like a different animal than what you had, right? One thing though, even though the gears are marked 0, +2, +4, etc, if you are going to advance or retart the timing , check it, don't rely on what the gear says. Also, before buttoning up the front timing cover, put a steel rule across the face of the block. sometimes the fuel pump eccentric can hit the steel cover due to manufacturer gear, and/or eccentric differences. This doesn't always occur, but you all own a ruler, right? Just my .02c. P/S, the last line on that cam card above is your target.........107 when degreeing.