fc3s690

iTrader: (1)

Well I planned on doing the 99 head swap to my 95 miata. I took the head to the shop earlier this week and this morning the machine shop told me that the miatas head and cams are out of spec and need replaced. One reason I was wanting to do this swap is not only for performance but also to eliminate the hydraulic lifters that are beginning to tick more and more. So you see Im in a pickle

its around $500 for all new lifters for my 95
or around $420 for new camshafts.

So my question is will the 95 head accept the 99 solid lifters and cams? Not only will this swap be a little cheaper but it should be a little performance gain do to the higher lift of the 99 cams correct?

Savington

iTrader: (31)

Cams don't magically go "out of spec". What is out of spec about them?

fc3s690

iTrader: (1)

I'm told that the bore is out of spec on both cams. The engine that the head came off of was from a thrust bearing failure engine. Not that it would have anything to do with this cam situation I'm just saying, nothing else from this engine has been salvaged. My own visual inspection it all looked ok bit I did no measurements myself.
When I'm told bore is to large I am thinking of the clearance between the cam and there caps I guess you could call it. Correct me I'm wrong please..

codrus

IIRC, when the thrust bearing fails, the crank starts machining the block thus filling the oil with little bits of iron shavings. Those go everywhere (once the filter is clogged and the bypass valve opens) and it ruins the cam journals.

--Ian

Savington

iTrader: (31)

lol, throw it all away. As Ian said, when the crank machines the block it throws iron filings into the oil system and they wreak absolute havoc on everything. The head is trash, the cams are trash, absolutely nothing is usable from a thrust bearing failure motor.

Throw it all away and buy a new head/cams.

railz

iTrader: (33)

you can repair the scores made from the bearing shavings by having your machine shop fill in the gouges with welds and have your cam bearing caps and head re-honed to factory specs.

The only thing you would need to replace are your cams since you should be able to source used set cheap.

webby459

iTrader: (8)

You guys need to check the prices on new heads from Mazda motorsports. Cheaper than you would think, and no worry of a fuxored journal. Price w/o valves cams or lifters $700, regardless of casting version. I have literally been through the ringer trying to find a good 4w head, I will do this if the current one doesn't check out.

ScottFW

iTrader: (4)

There's no doubt that the 99 head flows better, but if you are really annoyed by your hydraulic lifters ticking, they can be removed and cleaned with some solvent to clear out any gunk built up in them. I believe there's a writeup in the m.net garage section.

It seems to me there's been a lot more chatter lately about people selling junk heads from thrust bearing failure motors. That $700 from Mazda Motorports isn't too ridiculous, considering you could spend $400-500 on a junk head. It's getting to the point that if I'm buying a used head from a non-local seller I will want to see pics with all of the cam caps pulled.

fc3s690

iTrader: (1)

Well I have sourced out some hla's for a decent price so I may just stick with my 95 head now. But as far as performance gains, would a 95 head make anymore power running the 99 cams/lifters?

When this engine goes back in the car I will have my diy turbo set up installed so Im looking for the best turbo cams to run kind of.

If decent gains can be made running 99 cams I will most likely order corksports intake j-spec cam they sell for the 99, and track down a exhaust cam else where.

psiturbo

iTrader: (1)

integralcams.com

fc3s690

iTrader: (1)

I checked out Integralcams already, kinda out of my price range for cams. If I were to replace the cams I would most likely go with corksports intake cam and then find or order a stock exhaust cam.

chicksdigmiatas

iTrader: (11)

94-05 MAZDA MIATA MX5 1.8L 16 LIFTERS LASH ADJUSTERS BP : eBay Motors (item 350139455342 end time Mar-06-10 18:35:07 PST)


Those have been in my car for 4 years.

fc3s690

iTrader: (1)

decided to look for a reman'd 99 head and after maybe 10 phone calls to shops accross the U.S. I found one in Texas for $350 and a 1 yr warrenty. SCORE! never would have thought I could find a 99 head cheaper than evrything else.

fc3s690

iTrader: (1)

Cylinder Heads International - Quailty Rebuilt Cylinder Heads

The head should be in Friday, I'll let everyone know how it looks when it comes in.

Btw the site only lists the bp05 head, but when I called them and asked for the bp4w they had one there.

therieldeal

iTrader: (2)

the BP05 is cheaper if you look it up under escort GT vs. mazda...

LOL