A few engine question for you guys

[Lee.C]

Ok here we go guys  

for a start what are the advantages/disadvantages of Long and Short Manifolds for IDA's 

Also I have been wondering for a while what are the advantages/disadvantages of longer stroke and smaller pistons over a shorter stroke and bigger pistons 

Also the heads I have are machined for 90.5/92's  - is it possible to weld them up and then machine them back for 88's etc

I also remember reading on a thread on here about Smoothing out the inside of the Crank case for better air and oil flow - does anyone remember this 

And last of all I would like some more info on "autocraft" external oil pick ups as these seem like a really cool idea - Anyone know anything about these 

Alot of question I know - but thats what this place is all about - right 

[louisb]

Ok here we go guys  

for a start what are the advantages/disadvantages of Long and Short Manifolds for IDA's 

Shorter manifolds better for bottom end, taller manifolds better for top end.

Also I have been wondering for a while what are the advantages/disadvantages of longer stroke and smaller pistons over a shorter stroke and bigger pistons 

Also the heads I have are machined for 90.5/92's  - is it possible to weld them up and then machine them back for 88's etc

I also remember reading on a thread on here about Smoothing out the inside of the Crank case for better air and oil flow - does anyone remember this 

They did this in the HVW blueprinting engine and the nitrous engine.

And last of all I would like some more info on "autocraft" external oil pick ups as these seem like a really cool idea - Anyone know anything about these 

Alot of question I know - but thats what this place is all about - right 

[Lee.C]

Thanks for the info dude - I was just wondering do you know which issue of HVW had the case info 

[louisb]

Er, I was looking at it last night but I don't remember the issue. I will try to remember to look at it when I get home tonight and post it.

--louis

[louisb]

 

couldn't resist 

ok....sorry buddy...

from my understanding:
tall IDA manifolds (Skat Trak style) good for torque, easier to service carbs/plugs
short IDA manifolds good for top end power, bitch to get to plugs, carbs, may not clear fan housing as easily

I've read Porsche ran taller manifolds on the race-spec 911-based motors that were carbed, so maybe the whole theory is out the window. No....general rule of thumb is long runners make more mid-range than short stubby runners.

That is interesting. I have always been told, and I may be wrong and it wouldn't be the first time, that shorter manifolds produce higher air speeds which is better for torque. (And maybe I am just misinterpreting that as low end.) Taller manifolds are for higher horse power/rpm. (Tunnel ram vs a flat manifold in the V8 world) I will defer to Jim though since he has much more exp with IDAs and VWs than I do.

One thing about stroke, a shorter stroke engine will rev faster. (Also smaller pistons will do the same.) Longer stroke will help on the bottom end through better torque. And I agree with Jim, its all in the combo. Its why most people stick some wild cam or heads with huge ports on an engine and can't figure out why the engine is such a dog.

--louis

[Lee.C]

Thanks for the info dude but now I have TWO different opinions Louisb says that short manifold are better for bottom end power but you say they are better for top end power  I am a little confused 

Any thoughts on my other questions 

[louisb]

Thanks for the info dude but now I have TWO different opinions Louisb says that short manifold are better for bottom end power but you say they are better for top end power  I am a little confused 

Any thoughts on my other questions 

I would go with Jim's opinion. Like I say, he knows a lot more about performance VW engines than I do. I come from the V8 world and I am learning a lot of stuff doesn't always apply the same so I am still learning too. It is why I like bugging him with so many questions. 

--louis

[louisb]

Thanks for the info dude but now I have TWO different opinions Louisb says that short manifold are better for bottom end power but you say they are better for top end power  I am a little confused 

Any thoughts on my other questions 

Bentley Publishers sells it I think. Very boring book.....

That is a good point on the separate runners for the intake. It would be interesting to test this out and see which does what on a dyno. You would think with the longer runners, and I know we are only talking a couple of inches here, the gas droplets would have a better chance of falling out of suspension. Maybe not since the air velocity is still pretty high on these short runners even at low rpms.  And of course we havn't gotten into rod length and exhaust tunning here. (but at this point I am probably talking out my arse) I will check that book out, thanks.

--louis

[Lee.C]

OK new question - What about Rod Length - is there a "rule of thumb" when it comes to this length

[louisb]

Hey man...can you coach my wife about going with my opinion? 

Marry an Asian then come and talk to me about wives and opinions 

I'm still learning too louis!! You oughta visit the inside of my head around 2:30am when it goes into "wonder how this would work?" mode.

PS: I've always wanted to build a replica 350R small block Ford 289....know much about these?

Mustangs, and especially Shelbys are the cars that got me into cars. All I ever wanted from the time I was 9 or 10 until I got to be about 17 was a Shelby. then the prices went through the roof. By the way did you know the first Cobras and Shelby Mustangs had the 260 (think that is the right size.) small block ford and that Shelby originally wanted to use the Chevy 283 but they turned him down? I am sure I can find the specs on them but they changed often.

I build a lot of what I call paper engines too trying out different combos. And I have come up with some weird stuff let me tell you. But I don't think any of this is helping monkiboy out lol.

OK new question - What about Rod Length - is there a "rule of thumb" when it comes to this length

You will probably get more different answers on rod ratios than any other engine question than maybe cam shafts. If you want to read some real opinionated stuff check to Berg's Blue book article on rod ratios. (He is a short rod proponent.) Others like long rods. The ratio that Jim mentioned seems to be pretty common though. That is stock rod up to about 82 stroke, longer rods for bigger strokes.

Also for your heads/pcs I seem to remember someone saying you could have a machine shop make up some sort of sleeve or spacer but to be honest, if they are cut for 90.5s I would just run 90.5s. Unless you just have to have something different.

--louis

--louis

[nicolas]

i heard that too about short manifolds that would give more bottomend torque and taller manifolds would be better for high rpm engines. i am not an expert, but it was what i was told. and taller manifolds should have a better mixing of fuel and air than short ones.

as for welding up your heads i think it is possible, but i don't quite see the need for it, other than nostalgia or that you have an eye on a set of 88's 
90'5 piston and cylinders work just as good. i personnaly would stay away from 92 (thin walls) if you want to use the engine like yours at the moment. i mean all the time and everywhere.
if you want to use it in your buggy it could work with a wilder cam, but mudracing will suffer.

(btw jim did you get my mail?)

[nicolas]

no problem! i just saw the ad pop back up and i was intrigued the first time, but now i am more convinced about the use of that pump.

back to the topic

look at the engine of Kanase's car. that is a 1776 and that should make a nice combo. although i liked it more with the DCNF's... but i guess 48 IDA's will do the trick as well. does someone know what the difference is, performancewise... (in a smaller engine)

[louisb]

If you ever read the Kawel article in the HVWs engine build up book. (I have about worn my issue out) They try out a bunch of different engine combos in the article. One of the results I always found interesting was when they swapped out the 48 IDAs for a set of I think 45 dells and 40 idfs. (May have been 44 idfs.) The smaller carbs were actually very close to the webers until the upper RPM ranges. I think I remember a 5 - 10 hp difference between the IDAs and the 40 IDFs until about 6000ish then the smaller carbs ran out of air flow. My guess is the 42s would be about the same.

I know how IDAs are considered "the" carb to have, but I found it interesting in the recent Chirco engine buildoff that two of the engines ran 48 IDFs and made as much hp as the IDA motors. Some times I think we get too hung up on IDAs. (Having said that yes there will be a set on my '67. I have lusted after them for to long.  )

--louis

[Lee.C]

Again thank for the info - the main reason I ask about short manifolds is I have minimal clearenece under th back of the Manx and with the IDA's short ones are the way to go - I think

As for welding up the heads - again the main reason for this is that I want to CHOOSE my combo rather than be limited by my piston size Also you know me and "nostalgia" Do you know of anyone with some NOS empi 88's for sale

Also when you say I could use a wilder cam - is this because my manx is lighter weight 

Also I did think about using a set/pair of Weber 40dcn's - any thoughts

[louisb]

Actually, if I could lay my hands on a set of 48 DRLAs I would probably run them instead. Seems I remember Mark H was a big Dell fan too.

--louis

[Lee.C]

Don't worry Jim its all GOOD information  I really fancy building a 1679cc IDA'd motor now just like you mentioned Jim    I will let you guys know what I decide to do

One thing I do need to know is - Where can I get the "complete" jets for my IDA's as they didn't come with any 

oh yeah and one last thing does anyone know a GOOD carb rebuilder  I would really like to have mine restored/rebuilt/checked profesionaly - any thoughts 

P.S anyone have a link for the 88's 

[Lee.C]

Cheers dude and don't worry I will make sur eI have to do some machine work 

As for the jets - I ment that I need the "whole" unit - including the small brass nuts/screws that hold them in place   

[nicolas]

ah at last some people daring to step up and praise the other big carbs as IDF's and DRLA's!!! if i am correct on one of the best engines of the dyno session in hotvw's there was a set of dells and it had also 200 horsies. so it is said that IDA's run better at higher RPM's.

as for the engine (sorry lee)

there is a set of 3 88mm pistons for sale on the samba from steve beecher. that looks good, but you will need to find a 4th one...

if clearance is an issue go with the short manifolds. look up pictures of roger crago's ghia and dean's vw blue 67. they both ran 1641 engines with IDA and a 110 engle cam or so. so you don't have to rethink all the VW science by yourself 

and russel said that the mohlman 67 was a very nice car to drive and again a 69 x88 engine with a w 110 and some dells on it.

from my personal experience a great combo. you are wellcome to try it out if you come over to europe... i want to bring it to england later this month but the car won't be ready...

if there is one thing i would change about my current setup it is that i would have the case and heads machined to 90.5 and the cam changed to a W 120. the next step up, but probally less torque.

btw i ran this engine in my squareback 2 years ago when it was being restored. so it was a squareback without front and rear fenders, no hood, no trunklid and only two seats and a chair. kinda like a buggy  but we took it to the woods and had a blast with that engine. this will pull great and fun to drive. don't know about jumps though... as we didn't find any.

cheers

[Lee.C]

so you need idle jet holders, and jet stacks that slide over emulsion tubes? What about CSP? Doesn't Gunter carry that stuff?
Remember, idle jet holders are calibrated.

Correct dude - Anyone help 

[Lee.C]

"from my personal experience a great combo. you are wellcome to try it out if you come over to europe... i want to bring it to england later this month but the car won't be ready..."

Does this mean that you are running a 69x88 motor  by the way is this "nicolas" with the muppet racer

[nicolas]

no i am running a 69 x 87 engine that makes a 1641

and again no i am not nicolas from the muppetracer. too bad huh...

no we met at badcamberg, i was with speedwell at the meeting. you were parked at the swapmeet and talked about your friends rims. the ones with the aluminium outer and metal inner halves. this might ring a bell...

[Lee.C]

Ah I got you now - How you doing dude  - sorry you know how it is when you meet sooooooo many people in one week

As for the 1641 - they are AWSOME engines mine pulls like a train and has done 5000 very hard miles so far - all with no big problems

when are planing on coming to the UK and will your car be with you 

[nicolas]

maybe if we have a good price for the ferry or train, we come the weekend of the 28th to the T3D open door thingy.

but i haven't checked it out yet. i hope to come with the sqaureback, but there is a stock engine in it now and it has only run to PAT and Bug In. so i need to test it fully. it runs good, but it is an engine i bought a while back to get the car back on the road. the 1641 is now in my other type3.

but it will be a familytrip so the sqaure is the best option or just my daily waterpump... anyway that is the plan

for me it also have been crazy weeks, i dont know any people in belgium and now i have met quite a few also.

[Lee.C]

Cool dude  we will have to hook up for a beer I have never been to there open day 

Also guys I just found 88's for sale at Gene Bergs (see below)  do you think this means that the heads need to be machined the same as the
90.5 I am pretty sure it does and this is good news for me as my heads are already machined for these 

GB 003

88mm Cima/Mahle piston and cylinder set standard 69mm stroke (39.6mm pin height). These are thick wall spigots with cylinder sizes the same as standard 90.5mm, case 94.4mm, head 97mm, 6mm thick crown. Approximately 8.0:1 CR. (POTL) RW: 1.5/1.5/5. See Notes A, B, D, E. SW 30#
MSRP Price:    $492.95
Our Price:    $358.49
Cash Price:    $344.70

[Lee.C]

Really cos for me it works out about the same as a set of 87's from the UK 

well maybe alittle more