1600 turbo build thread

[buguy]

Yeah I will have to do some more research. I don't want it to cost any more money, so if I could use those same stockish 40x35 heads and it would be more powerful then I can't imagine not doing it. If I read right the 94mm cylinders are plenty thick, so reliability shouldn't change. Right now I don't want to spend much extra because I still want to build a FI system before doing a real build.
Physical size wouldn't really change would it? Not changing rods or crank.

[Chip Birks]

Honestly, I'd do a thick wall 1835 if it were me. Width shouldn't change much, assuming you think ahead and get a chamber sized appropriately.

[buguy]

I'm going to have Tim's make me up a set of heads. He recommended the 40x35 heads with stock bore. Also recommended having Engle grind me a W90 on 112 LSA. I was thinking I needed to get my p&c first, set the deck height, then have the chambers set. But I guess I can just set the deck height to whatever it needs to be to work with the chamber size of the heads.

I have also considered a thick wall 92 but figured with the low revs I'd be turning, 94's wouldn't be a biggy. I'd have to ask about what cam with either of those bores.
If I had bigger balls id love to put on a set of those squishy pistons!

[Clonebug]

You might want to measure your deck height before ordering heads......they will probably come with 60cc chambers.
On my 88mm barrels I needed 52 cc chambers to get 7.8:1 compression with .062 deck.
If I could do it over again I would have shot for .040 deck and get the heads cut for the compression I wanted to run.
Using an engine build calculator a 69X94 with .040 deck and 60cc chambers will give you 8.1:1 compression. I wouldn't run too small of a cam since boost will make your engine want to rev and rpm is hp.
My engine peaks at 5200 rpm with a W-100 cam...any shifts at a lower rpm and you will be well into the lag on most any turbo except a tiny one. The W-90 will probably peak earlier and you don't really want that in my opinion. If you are using the TD04L-13T(If it will work in drawthrough) you need more rpm unless you make the engine bigger like with 94mm P/C's. Seems to me that little cam would choke a 1915 and you should have a W-100 or larger to take advantage of the flow a bigger head would provide........
It's just my opinion though and I am not an engine builder....just an engine booster.......

Looks to me you are well on your way to the snowball effect that you didn't really want to get into.
Did you ever inspect those pistons real close and find any cracks???

Since you have opened up the case you might as well do a complete rebuild now and start from scratch. Just remember once you get it going that you have not fixed the reason the engine developed blowby and you will go right back into it unless you are very careful and work slowly into the boost levels.
How many miles did it take to develop the issue you have????

Remember....baby steps............anything over 6 lbs boost is a whole new world and you need ignition control to protect your engine whether it is draw through or blow through.
You need to know how much advance you are running for a given boost level and rpm in order to protect that new engine which is now a bigger pile of money............

[buguy]

That's true. We have most machines to do whatever I need with the engine but I'd just as soon have Tim's cut my head's.
Cam.... I have no clue. Zero experience with picking a cam. Tim's first recommended a TCS 10 I think.. 247/246 cam(the W90 is 224 I think) but was concerned with my little turbo being enough and that was on a stock bore size. But he really doesn't know the turbo so it was just a guess I'm sure. And yes I'm sure if I went to bigger bore I would need a different cam. I didn't even ask about that.
And I'm hoping this isn't a snowball. Heads should be no different than the ones I intended to use on the stock bore, and the p&c are pretty much the same price.
I looked the pistons over and didn't see anything that looked obvious. I didn't take a magnifying glass or anything to them though. Once I saw the huge ring gaps I figured that's where my trouble was. And really I still don't know that I had blow by, or at least not worse than before. I really never paid attention to it. It was when I got some smoke coming out (just a little) of the breather is when I got to looking at it. Once I fixed my drain and changed the oil it "seemed" to have gone away. But again, with the huge ring gap I'm sure there was some. I put air into the cylinders and I heard more from the valves than anything else.
I plan to just reuse the crank and Ross because I don't want to do a full build right now. I'd be looking at at least $700 for a crank and rods. Then I would surely stroke it and then I don't think the turbo would work anymore and then the heads would need to be bigger etc.... So for now just some new bearings.
I also found that when I pulled my distributor out, I found that the set screw I put in to limit my timing was gone. Weird though because I checked the timing a couple times and it wasn't going past 24 degrees so I don't know. I never heard even a hint of detonation though.
I do know for sure, and clone you may have noticed similar results, when I put the manual boost controller on it ramped up boost way quicker than it did before.
So for right now I want to have the guy check out the case and be sure it's ok to use. Then I will make a final decision on bore size and order up the p&c and cam & lifters, and bearings. I can then set my deck height and may as well button up the shortblock. Then order heads. Hopefully I will have my header built by the time the p&c get here so I can get it back on the road soon. I'm going to roll the dice and make a more positive stop on the timing. I'm really hoping I can get this running then start getting what I need for the FI conversion.
I'm still not feeling too bad about doing this work. I only had about $400-$450 in the engine and turbo system. Should be at about another grand or so with this work. Not too terribly expensive.

[Chip Birks]

Sorry, I didn't read all the above, I just saw you saying something about measuring and stuff and then deciding to get your heads cut based on what you find. I would recommend that you go into it with a plan. "I'm going to run X.X:1 compression, I want .0YY deck height, therefore my head chambers need to be ZZcc. Use your planned bore and stroke and solve for Z. Set deck around .04 to .06. Run compression at probably 8:1.

I don't suggest 92s because of rpm. I suggest them because of boost. Much like clones 88s, though not quite as thick.

[buguy]

Sure I know the 92 are thick. I was just thinking since I'm not doing anything crazy the 94 would hold up too. But I will certainly take the 92's into consideration. I suppose it's really not going to be a ton of difference in power between any of them, but the strength might be just enough more to keep me out of trouble. I haven't been able to find good info on the thickness of the 94's, but they certainly can't be as thick as the 92's.
And your right I should have a plan but unfortunately I simply don't have the knowledge to make an informed decision as to what is best. I do want to keep CR low so I can put some boost to it. I guess I could let the calculators do the rest.

[buguy]

Speaking of calculators, does anyone know of one I can plug numbers into to get my desired chamber volume?

[Clonebug]

https://www.cbperformance.com/v/enginecalc.html

[Chip Birks]

Sure I know the 92 are thick. I was just thinking since I'm not doing anything crazy the 94 would hold up too. But I will certainly take the 92's into consideration. I suppose it's really not going to be a ton of difference in power between any of them, but the strength might be just enough more to keep me out of trouble. I haven't been able to find good info on the thickness of the 94's, but they certainly can't be as thick as the 92's.
And your right I should have a plan but unfortunately I simply don't have the knowledge to make an informed decision as to what is best. I do want to keep CR low so I can put some boost to it. I guess I could let the calculators do the rest.

I can measure a 94 for you. I don't have a tw 92 available to measure, but could compare a 94, an 87, and an 85.5.

[buguy]

If you would that would be awesome. I've seen numbers somewhere for the tw 92.
And thanks clone. I will plug some numbers in and see what I can get.
I really appreciate everyone's help. This is all new for me and I want to get it right.

[buguy]

So according to the calculator with a 94 bore and a. 048 deck height I would need a 62cc chamber to achieve a 7.8 cr.. With a 92 bore and. 048 deck height I would need a 60cc chamber size to get. 7.7 cr. Sounds doable. And according to this list there are some available but I'm sure any of them could make whatever I would need. I think I read Tim's does it for free and port matches the end pieces for free if you send them. I didn't ask them directly though.
https://www.thesamba.com/vw/forum/viewt ... p?t=573099

[Chip Birks]

Dang, I'm glad I shoot for more compression with my builds, its tough to get many heads that have chambers big enough to get that low. 62cc are big chambers!

[buguy]

I wasn't even really planning on going that high with the compression!
For fun i ran the calculator for a 2276 and I would need 75cc chambers with a. 048 deck height to get down to 8:1!!

[Clonebug]

Don't be afraid to bump the compression to 8.0:1 especially if you go with a W-100 or larger cam.