4M Performance package - Suggestions please.

[TheToyman75]

The MS75 is on Historic rego so I can't give in to temptation and slot a 1UZ into it. With that in mind I want to build a "performance" engine for it.

It needs to be a package that meets the Historic rego requirements so no twin cam heads etc. It will need to use the early 4M or 2M head so it looks right and I don't want it to be any bigger in the bore than a 4M for reliability. Has anyone got a tried and true package they recommend ?

I have a set of the factory twin card and air cleaner on there way for it (from an MS5x series 2M) and will be sourcing an engine to build it into as the 75 doesn not have its original block in it anyway. A 5M-E electronic ignition is planned as well as a 5M-GE or 7M-GE reduction drive starter motor. The stock 4spd Manual will be staying.

I am not expecting earth shattering results, just a little extra. I'd like to hear from those that have as opposed to random theory.

Thanks in Advance.

[IN 05 NT]

all i can say is that extractors and the zorst actually gave the boat anchor a lil bit of a tug.....as in you can actually rev the thing over 4000rpm

thats as far as ive got

[KGB]

Sory but i have to ask for you what's the difference in club & historic Rego as in does that mean you cant race historic ...

Any way i suppose it comes down to basic Na tech with to day,s knowledge of fuel , St / Cp ratios , cam grinding , traktor zorst , timing curve ect to make it quicker than the cars running round in their day ..

Keith: Ps a small pic of your ride might help i had a 112 & 123 & loved em for what they were but not all o here know what a 73 looks like

[IN 05 NT]

historic rego is limited to modification that were available at that period...early 70's

ie if there were an off the shelf supercharger kit for the 4m produced, and you could show evidence of it being a period modification, you can then use it,...(this is how i understand it)

[cambelt]

Just as my friend thru out a very worked early 4M 6 months ago , ported head , big cam, im not sure what else , same old story didnt think it would be of use .
i,ll let GT say .
Dave

[ViPeR_NiPPleX]

could you stroke a 4m using a 7m crank?

modify/enlarge the twin carb chokes to allow more cfm at higher rpm, or run triple mikunis/solex/weber/dellortos. Regrind a good camshaft for desired powerband/revs and make sure the head flows sufficiently. Build extractors to length and enjoy.. If only it were so simple

[TheToyman75]

Historic rego does not tecnically allow for any modifications.

The vehicle must be as it left the showroom and can have most of the dealer options fitted. There are exceptions in the area of safety - Ie fitting of retractable seat belts, disc brakes or suspension. All within reason of course.

The best thing is if you are wanting historic rego on a vehicle contact the borad via email to discuss what you have in mind first.

[ViPeR_NiPPleX]

so pretty much you gotta clang together a bunch of factory parts... port match the carby/intake/head, and polish the c/chamber. Might be able to get away with that? Balance the rotating assembly.. lightflywheel.. *shrug*

[river]

Hi,

I have a set of the factory twin card and air cleaner on there way for it (from an MS5x series 2M) and will be sourcing an engine to build it into as the 75 doesn not have its original block in it anyway. A 5M-E electronic ignition is planned as well as a 5M-GE or 7M-GE reduction drive starter motor. The stock 4spd Manual will be staying.

Hmmm... doesn't sound very historic.... or required for safety reasons????????

seeyuzz
river

[gianttomato]

7M crank, 5M block, 5/6MG pistons, early 41030 or 41032 head - that shit doesn't just bolt together. Crank nose needs to be modified to take the timing chain gear and not sure which conrods you're meant to use. You can take that combo to 3.1 litres. Cam - you'll need it welded up and ground if you want anything vaguely decent. M-B or M-D twin carbs. None of this will be terribly cheap to do.

Can you fit extractors or do you have to run a standard manifold? If it's a problem maybe Powerporting the exhaust might be the only solution.

Just put a W50 in there. Can't tell until you look under it.

Clubagreenie's mate has some such thing.

The other thing that crossed my mind was 6MGE with triples. The look will still be old school.

[abently]

Firstly, I would strongly advise against a cam regrind which doesn't include any welding of the lobes. It is practically money wasted for little gain at the expense of increased valvetrain wear.

Shave the block such that piston to head clearance is about 0.8mm using a standard 1.2/1.3mm Head gasket. Use some flat top to slightly domed pistons to increase the CR as much as possible.

This is a $1000 rebuild and will give you a healthy improvement.

Using the standard 4M Head on the 2M bottom end should bump up max power to somewhere near 6200Rpm which would complement a performance based camshaft.

If your happy to spend another $1000-$2000 on top, you could afford to have the Cylinder Head/ports modified but realistically leave that decision till after a general budget smart build as you might be surprised by how much extra oomph the new Engine has.

[cambelt]

abently have you even built a early M engine before?
Dave

[Norbie]

A bloke in the Celica club up here built a 4M a few years back. He used a 6M crank, high-compression pistons, some sort of angry-sounding cam and twin SU carbs. Performance was roughly equal to my MA61 with a stock 6M-GE in it, which I think is all you can expect unless you're willing to throw buckets of money at it.

[Gttwinturbomk3]

Hi there mate,

I would suggest trying to find a decent mteu like what i have got in my ma63 celicasupra. My engine has run fine as long as you dont give them to much and let them run to hot (its simple really?) They go damb well and if you got it running spot-on you could increase the boost to around 12psi through the factory t3 garrett turbo and maybe exhaust and filter (like i have done) and you will have a rare MS75 which is unique, and with better performance than anything mentioned above. You would need to put a intercooler on it that is a MUST! I have run up to 14psi before with my water/air intercooler and i estimate it was doing late 14 second 1/4 miles, 2.0 sohc turbocharged

James

[gianttomato]

MTEU and 6MGE (yes I know I suggested it) talk is moot. Rod must have it looking externally similar for historic rego.

Abently, not sure you've seen an early M before judging by some of your comments. ALL the early pistons are domed to varying degrees.

Rod, you should be able to source 5M block and 7M crank and rods for nothing. Some guy with a VG30 in an MA61who posts on here recently built up a 5MGE - got some brand new pistons from the US with a lot of high top action. Find his source and buy them 40 thou over.