Mystery Motor

[Bob Brugge]

Hey guys!

First thread here, have specific questions.

I have a t4 case and heads, needs absolutely everything else. Luckily I have a buddy who has a few parts I can score here and there.

What I am interested in is what to look for, are any production numbers specifically better than others?

I know a little bit about T1 motors and what to look for as far as defects, cracks, etc in the heads. What areas are of concern with these motors?

The case and heads are opened up for 94mm slugs, I am assuming that is stock for some specific year or option?

I am trying to figure out exactly what I have and what its potential is. I can post part numbers if required but not pics, I am one of the 1 percent of ppl that don't have a cell phone.

Thanks in advance.

[damo99]

part #'s will help identify your block
but what are your plans for it (what size are you going to build ect)
the only part of a type 4 case i have seen that might have problems is where the oil pickup
is bolted to, some people do this up way to tight and it cracks the case at that point.
but it can be welded up easily

[Bob Brugge]

Case -on breather box- CB026578 with either a small letter e next to it or a weird dimple. PN#004.100.102A
Heads 021.101.371.Q right inside by one of the intake springs.
Plans include stuffing 90mm cw crank in it w/ 105mm jugs and a turbo. I intend to use this engine for 1/8 mile drag racing. Have several other engine builds in the works, just trying to somehow add apples to apples. Hoping for 3k+cc when finished. I am sure I could do better w/ custom heads, but that is an upgrade or two away.
Hoping I somehow got something worth putting the time and $$ into

['77 Westy]

I’m new too but can probably answer your questions – and raise one that you need to think about.
CB is a 1700 case and the heads are 1700 too, originally with 39.3mm x 33mm valves. Sounds like the heads have been cut for 2.0 jugs but they fit straight in a 1700 case. All type 4 cases are essentially the same so a 1700 as a base is as good as any.
Unless that 90mm stroke was a typo you need to do some homework, it would require some very serious case modifications. Anything is possible but I’d start with a maximum of 80mm and see how difficult that is.

[Bob Brugge]

80mm huh? I will keep that in mind I know the 90mm would require a stupid amount of clearencing, I have been looking at pics ppl have posted of their clearencing jobs. Some even have to notch the cam shaft for the c/w's.

[Piledriver]

All the cases have the same cylinder register (don't remember what it is, getting old)
the 1.8L and 2Ls all had the same 105mm cylinder register in the heads, the 1700 used 100mm register.

The cam clearancing needs(case to a much lesser extent) depends on several things, journal size, the specific rods (how they are shaped at the cap and bolt size) and the base circle of the cam.
You can probably do >80mm++ with the EMW rods on a 2L journal, maybe with the 2" "chevy" (buick) journal, but with T1 journals buy lots of extra bits for the die grinder.

As an example only Brand A rods may clear everything by miles and brand B may not, even though they are the same nominal size, same bolts etc.
A similar rod with 3/8" bolts will need much more room to swing than one with 5/16" cap screws, esp as it will be likely be built heavier overall.

...It also appears you can only get decent Clevite 77 trimetal rod bearings anymore in the 2" "chevy" journal,...
...so considering T1 or T4 journal rods makes little sense anymore at least on an all out effort as you seem to be after.
The Dodge 2.2/2.4 C77 rod bearings are available than can work for the T4 but that requires custom work on rods that makes ~zero economic sense if staring with a blank slate.

You want to run the biggest cam base circle you can, and ideally you want the longest stroke.
Also understand that to feed a huge motor you need huge heads, and the cost seems to go up ~exponentially per cc/CFM once you get much past stock.

What you may or may not have picked up is that T4s head deck rigidity//head seal with std heads is not ideal for boost, particularly when you cut a large hunks of metal out for larger bores.
It can be done.
It can also be done without cutting large hunks of metal out of the heads...
It has been done... But do your homework.
Most if not all of the folks who have done it successfully for more than "weekend toy" use have used aluminum/nickasil cylinders.(on big motors)

You will want to avoid a 105mm bore as even in the best iron jugs the ring seal is going to go away quickly boosted, it it ever happens.
I'm not even sure Nickies would work well under high boost at 105mm.

[Wally]

What Pile said.
As you said elsewhere you were going to race with the Baja, keep it MUCH smaller in cc's and use a really good turbocharger that yields little backpressure. Pls read into that. I ran just a small-ish 2,2ltr at a little over 400 hp on a Time Attack race season and it lived. Just to prove you really don't need the big displacement for hp with a turbo. My idea is that longlivety matters over everything else with an aircooled VW and racing it

So, I would suggest s/th like 78x94 to keep the heads sealed and jugs cooled well enough for racing.
Also EFI and serious intercooling would be a must imo.

GL!
Walter

[Piledriver]

....
Also EFI and serious intercooling would be a must imo.

GL!
Walter

...and great knock control to go with it.
A solidly supported, well developed, complete system is what Wallys setup was (is?), not just random parts.
Read his build threads to see it done right.