Gents
I’m asking for some advice on mainly head modifications you’d recommend. I’ve had several BMWs over the years and my 90 318IS (while I was in Europe) was my first new car purchase and regretted selling it when I moved back to the states. Several years back, I found a 1 family 1991 318IS with a timing chain tragedy story with some records. A SoCal car, the body and chassis were rust free and clean (except for a bit of rust on the flange on the trunk deck that holds the rubber gasket) with upholstery damaged seats and badly faded paint and a cracked dash; a solid base to start from.
I’ve since sourced a 91 M42 from a wrecked E30 ‘Vert with 130K with records and seems to have been well kept. My local pick and pull had a late M42 (July 95) 318ti that I pulled the timing chain case and assembly off to eliminate many of the early M42 TC issues. While I’m in there I picked the head as well. Hoping that my machine shop will find no cracks and then trims the head a bit (I know about the corresponding need to shave the upper TC Cover as well) I ask for your suggestions on head modifications
The question I pose to you is what best bang for the buck head mods you’d suggest. Changing over to solid lifters etc is more effort and money than I can justify for the cars intended purpose of being a Classic Daily Driver that may see spirited drives in the Texas hill country and is just fun to drive. I have 5 vintage Alfas and those consume plenty of time and cash as it is. I’m of the opinion lightened reciprocating mass is my best option and I ask for your suggestions on achieving this.
The later M42 head has the 6mm valve stems and the lighter lifters used in the M50. So far so good. I do not need this car to rev to 7500 so what I’m looking for are suggestions on valve springs that are good value on price performance and any other suggestions. I understand the later valve springs are lighter than the early ones but wonder if there is a magic bullet solution in sourcing valve springs. Any idea about the cost of the Metric Mechanic “Beehive” spring sets? Are they worth it? Is this the one essential head mod you’d suggest or am I looking in the wrong place for a bump in responsiveness? Nothing is known about the junkyard head I pulled-should I be looking at a set of lifters as a maintenance item for this build?
I gather there are advantages to swapping the earlier 1991 cams onto the 1995 head. I’ve sourced a 325 flywheel (shaved to about 15 or 16 pounds and starter and will go with a Chip and have rebuilt a set of Bosch 4 pintle Mustang FI. I’ve done some light porting and polishing of heads in the past and have access to a Flex shaft Foredom and want to work on increasing the flow of the heads especially on the intake side.
While I’m in there at the machine shop I’ll have new valve guides fitted and my understanding is the later M42 ti head already has lightened keepers. I will be using the early M42 intake manifold and stock exhaust. Other stuff to be done: new TC and Guides, loctight the oil pan nuts that are infamous, new Motor mounts, new clutch and TO bearing, replace crankcase and rear main seal, change wherever possible to the upgraded metal TC gaskets. replace the oil relief valve, all gaskets and O rings, all cooling components, vacuum lines, new seals and bearings on the tranny etc. That and all the other refurbed items as part of a restoration-suspension (anything rubber), 21 mm front sway bar, new Shocks and Springs, PS rack swap from a e46, rebuild alternator, PS pump, starter and AC Compressor etc while the engine is out. I’ve been hitting the local junk yards and CL and Ebay accumulating and rebuilding the parts for several years.
I’ve not contributed much to the M42 club site as its taken time to accumulate the parts and to really study the forums and boards on best practices so I thank you for all the collective knowledge and look forward to your suggestions.
Thanks
Steve (aka-austinalfa)
Topic: New to this forum but not to wrenching. Asking for advice on late M42 head mods (Read 1886 times)