Magnum Engine

Just stumbled across this site today,, pretty kick ass B series site. Forgive me if this is rambling, its late here :-p

Anyhow I was noticing a lot of threads about the Magnum Engine..

The Mazda I own is a 87' B2000. I bought it from my dad about 11 yrs ago, and a few years prior to that he got it and cash from my uncle, for my dads 911.

When my uncle got the truck it had a seized up motor, so he ordered a take out motor, which is the motor that is still currently in it.

It has 147,000 miles on it (based on an estimation of 50,000 miles from Japan).

The reason for this post is that it has the magnum valve cover on it. (It also used to have the oil cooler, and a carb on a manifold. The carbs linkage didn't match up anywhere close to what I needed so a few years ago I junked that and the oil cooler adapter..) Other than changing the water pump, timing belt, and oil changes the motor is unaltered from when it was installed. Well other then getting a Holley 5200 and headers installed.

I pulled the plugs tonight after reading posts on the magnum engine. In the Haynes manual compression for a B2000/B2200 should be 173 standard

My compression tested as follows:
Cyl #1 183
Cyl #2 185
Cyl #3 185
Cyl #4 184

Since I live at sea level, using the following formula, (dynamic compression)^1.3 *14.7=psi
gives the dynamic compressions, which then for a NA FE/F2 engine, add 2 to convert to static compression.

This shows that engines compression ratio is as follows: (This same formula puts B2000 w/ 173psi as being an 8.66:1 ratio)
cyl #1 is 8.96:1 (give or take 0.1 due to rounding), cyl #2 9.0:1 , cyl #3 9.0:1 , cyl #4 8.9:1


As far as the shape of the pistons I couldnt get really good look but they had reliefs for the valves in the top of the piston.

In a few days I am going to pull the oil pan and take a look around down there.

I know pictures are worth more than words so as soon as my oil pan gasket arrives (hopefully with in 7-14days they said) I will be posting pictures of my findings. Also I am going to try to use a scope at work to get some pictures or video of the top of the piston from inside the cylinder

welcome to thescene wher you from??...and get the pics up asap man

Thanks, I'm from the boring oregon coast

Oh yeah forgot to mention that when I went to get a timing belt for the engine, I had to take the belt back cause the one for the an 87 B2000 was a few millimeters too wide and would have been rubbing the timing belt covers so he had to get me one that was listed as a special part number in the catalog... *shrugs* When I take the covers off this weekend I will post what brand and part number fit correctly.

im in longview washington

where exactly

oops

ok gotchya

mazda fest is coming up in july at rooster rock state park yo should attend

Yeah I saw and ad for that on someones sig, Im sure my truck won't be all fixed up by then but I'm totally going to go check it out.

cool man lotsa good guys on this site

first off.......welcome to the site man. glad you found us. there is a great bunch of guys here that are willing to help with anything you need. we all are pic whores so you will get "post pics" alot...lol
secondly.......dude you are awsome to take apart your engine to scope out what you have and share your findings. i know its cool to find out what you have but its also great for us to hear seeing as though no one really knows exactly whats going on with these magnum engines. all we really know is what we've read. one girl bought one off of ebay but has had shipping problems and hasnt installed it yet (that i know of). you will end up being asked a bagillion questions about it so be prepared. and as always.........welcome home vg30e86, welcome home.

Well UPS rescheduled the delivery of my gasket sets until the 30th. GRR. So it looks like the inspection and photos are going to have to wait until next weekend. Guess I get to spend this one rebuilding turbos, oh well. DOH.