Quote Originally Posted by dave w View Post
I was thinking about ordering one of these Memcals, but the shipping seemed excessive to me!

dave w
Didn't see that coming! Thanks for a great laugh first thing in the AM.

We had started a memcal knock filter number list trying to find differences and similarity's but the thread went stale, I do have and have posted here somewhere that knock sensors are frequency specific for cubic inch, but that may have been with ESC. Now memcal knock filter different numbers are coming into play? Also while doing my sons IH 345 engine with 16197427 PCM system he found different part number for manual to auto tranny. So the knock sensor frequency specific to engine bore size may be a ever changing issue with all the different knock filters in Memcals?

You've been around long enough to know dangers of knock! Little ping won't hurt, but if knock system is not working correctly and you hear knock? Big issue... be careful! Depending on mask ID and the 6000 possibilities of spark advance changes do to bias, what your timing table says and what is happening at timing marks can be 2 different worlds! Take for instance the same $OE bin we both used for starters then roughing in timing table. 5.7L has IIRC 9.84 degree warm bias and 20.04 cold spark bias. 7.4L has 0 degree warm spark bias and 20.04 cold spark bias. POOF! 9.84 degree difference at timing marks when warm just because we used a 7.4L bin and made it a 5.7L bin!

For Jeeps and Guns we are having excellent results with 427 PCM 5.7L memcal using the manual trans knock sensor. Motor is new and tight, using real time advance numbers that should be correct for engine then adding 4 degrees starts to show some retard, adding 6 shows more! So pretty good for a conversion... if you spark table is relatively correct for your engine and your getting knock counts it could be just over sensitive because of engine differences. Over torque will make over sensitive, Teflon tape desensitizes, brass elbow make even more less sensitive.

Slippery slope here using knock sensor as gospel truth in a conversion!

Roughing in spark advance from original motor, making sure timing in bin is actually correct at timing marks when motor is totally warmed up, leaving all other spark bias settings stock is a good starting point, pick an area like 2000 RPM 75-100 map and add 6 degrees so you can half throttle from idle and watch results, test, rinse and repeat...