Over the past 12 months I've discovered that engine building is quite fun.

I've also discovered that the difficulty lies in coming up with a good combination.

The building bit is fun and it's satisfying to check and measure everything so you know it's going to be right. It's also nice to keep in the back of your mind that all your hard work should pay off.

Another fun thing to do is research your engine specifications. There are so many schools of thought and engine combinations that it just makes the mind boggle.

I'll tell you my story and you can read it if you're bored.

I had a reasonably stong engine of the Stan Pobjoy philosopy that I was quite happy with. I pulled it apart to replace the worn heads and see if the rings and bearings needed a freshen up.

I'd thought I'd go a bit further by replacing the camshaft to something with just a little bit more lift.

The funny thing is that wanting more is such a trap. I've heard lots of stories about people who've just pushed a combination too far upset things. I've now done it twice.

The first mistake I made was with valve size. I thought bigger has got to be better and went wth some 44mm inlet valves on some street eliminator heads. They were fine for about 1000 kms then the valve springs gave up and I started floating the valves at 6000 rpm. We shimmed them up at a hillclimb. We did it in a motel car park in the rain! That was only good for 500 kms then the valves started floating again. I went through another set of valve springs before deciding to get some mild, small valve heads and avoid that problem in the future.

Interestingly enough I got 10% more power on the dyno out of 044s with 40 x 35 heads on 10:1 compression than I did with the big valve street eliminators on 9.5:1 compression.

This engine combo was good for 88 rear wheel horsepower and a 14.9 second quarter at WISID in my oval with a full size pulley.

The 044s were old and were brought back to life only for temporary service.

After 2 years of supersprints, drags and street driving I ended up replacing them with some aircooled.net level 5 heads ported and polished by some DRD bloke. I was disappointed when I saw them becasue the ports looked small. They are simply mini D ports and are standard size except where the O goes into the D. But the attention to detail is really impressive on not only the heads but on the manifolds I got at the same time.

My second mistake was the cam and lifter change. The refreshed engine with the new heads and Webcam 109 felt strong. Previously I had to get right up the engine even before I let out the clutch to make it perform. The new combination had more torque. You could cruise along and put your foot into it and it would just take off. Im not sure whether that's the portwork, the taller manifolds, 0.5mm extra lift or the combination.

I say could because it only lasted 2 supersprints and 1500 kilometers before the lifters stopped spinning and wore badly. I thought I did the right thing using reground original lifters and not the after-market rubbish.

I've looked on a lot of engine building forums to try and get to the bottom of the cam and lifter wear problem and let me tell you it's a hot topic. I've considered going to and engle cam with standard lifters. Or getting another webcam but this time with the recommended SLR treated lifters. I've considered using CB performance cam and matching lifters. Each time I've wondered if I should push the combo a little bit more with some extra duration or lift, but then I woke up to myelf.

Just go with something that's proven instead of optimistically thinking I'm going to come up with the magic combo. I don't have time for that! I missed 3 races this year because I was pissing about with my engine. Now I think I'm just going to put the old steroid cam and lifters back in the engine because they copped 3 years of punishment and still look great.

With a bullet proof combination in my oval perhaps I can build something ridiculous just for fun.

Has anyone else got a suggestion for a bullet proof combination that's good for circuit racing and still has a VW logo on it and doesn't need coolant?

Gosh what a long post. I don't know what came over me.

CYA CT

What about steel cams??

Actually you should chat to Ryan (RCB78) on SBO and Shoptalk.
He has a 1916 as well and has had some of the same problems. He is/was running Level 6 AC.net heads but the ones from AJ not DRD

Apparently he is getting big power from it, but has gone through some cams.
"Something" happened last time and John C. "fixed" things - never really got the full story

Here is a list of hotties
http://www.geocities.com/enginecookbook/menu.htm 

Ryans is listed there but it is like 5y old as it was a mild 1776 then




[ Edited on 13-10-2005 by Bizarre ]

If it ain't broke, don't fix it, huh...

Hi Barry,

My cam didn't wear it just got scored a bit, it was surprisingly little when you see how much it wore away the lifters. The problem was with the lifters. Or should I say it was with compatibility which may be machining angles or metal hardness.

Hi Glenn,

If it ain't broke don't fix it? Shouldn't that be; If it ain't broke you can still piss about modifying it?

I've got another lesson. Brand names don't make you go faster. I also found out that my 009 distributor made more horsepower with a better curve than a more expensive mallory dizzy. Luckily I borrowed that one. I don't believe totally in dyno numbers. It just confirmed that to me that it didn't feel any better than the 009.

CYA CT

P.S How's the article coming on Glenn?

[ Edited on 13-10-2005 by fullnoise ]

[ Edited on 13-10-2005 by fullnoise ]

While not going through as many engines as some people seem to. I am currently getting specs together for a 2000CC max race engine. I went to a good VW engine builder last time, and he put together a really awesome street/motorkhana combo. Good spread of torque and also revs to 6k. But i have flogged that to bits, as i have been running it in sprints/hillclimb/autocross etc something that it wasn't made to do.

I would be very interested in combo's other poeple are running, i have also drivewn a very hypo 1300CC beetle, and found that to be nice, but not sure if it has enough torque for rally, as it ran a k8 cam. so many decisions so little money

Was that Guy Hardings Targa Tasmania beetle? That had a high revving 1300 in it from memory. That concept seems kind of Italian.

I think Dave Becker has an interesting engine that puts out lots of grunt. He's put his engine combo on here before.

How many other people on here have had a go at a decent engine?

Has anyone got IDAs, competition eliminator heads or exotic parts in their engine?

CYA CT:vader

That motor of Super Steve's has some mumbo!

Come on a bit high though.
Fire crackers at 5kish

Nice thread, I will be watching with interest. I'd love to play with engine combos, but time, money and other interests styfle that one.

I can see why people turn to the watery side, especially if they've tried several combos and had similar problems as you describe above CT.

Yep, it's a real art-form, to be able to build great combos that are proven to last and last.

FWIW, someone posted a link to a site that gave the following "mechanical redlines" depending upon stroke length.

69mm stroke = 8440 redline
74mm = 7860
76mm = 7625
78mm = 7600
82mm = 7080
84mm = 6910
86mm = 6745

[ Edited on 14-10-2005 by 56astro ]

When i build a decent size stroker its sure as hell going to rev harder than those redlines! built to go, not to last!

So there'd be no warranty with your engines then??

That'd make it a very expensive hobby.

' Or getting another webcam but this time with the recommended SLR treated lifters.'


I reckon you are on the money there. New cams can be made outa lots of different content metals and new compatible hardness/metals in the lifters. Face angle can be different too.

Kinda like having the right compound brake pads for your rotor type.

I think there is two parts of this discussion.

1/ What is the mechanically sweet combo's

and

2/ What combo has the best go.


The trick is blending 1 and 2 to fit budget and desired result.

Thats where Stan-the-man and many others have the experiences to know what works and what doesn't.

kkk

Hey CTTander,xxxxa good topic,Ill start of with a combo that i was going to race with before diciding to do before a T4.(now Subie).......Engine 2087cc....44IDF webbers....4063 bugpack camshaft....Scat manifiolds....82mm scat crank....vw rods with 90.5mm Cima barrels & Pistons...Heads with 40/37valves and ported.When i worked this out about 10year ago the compression would of been about 9.93:1. The spark use 009.....A good over maybe 140 to 160hp@6500....(note) ill will stand corrected on these figures....JVLRacing

[ Edited on 15/10/2005 by jvl054 ]

[ Edited on 15/10/2005 by jvl054 ]

It's easy to marry the parts together on paper but it's harder to make them fit in the engine.

The webcam had a larger base circle and larger lobes than my previous cam. I realised when I was putting it in that I only just had the 1mm clearence between to lobe at full lift and the lifter when it was seated in the bore. If I didn't have reground lifters I wouldn't have had the required clearence and the lifter bores would need to be machined. So you can buy a cam that a lot of people are talking about on forums but it won't necessarily fit in a standard case with a set of new lifters. Nobody seems to mention that.

I was considering a ratio rocker cam because they look to have a more gentle profile. However I still want to use alloy pushrods to keep the valve train light. Now, does a 1.4:1 ratio rocker put 127% more pressure on the pushrods and cam? It's multiplying the lift on one side but it's also multiplying the spring pressure by the same amount isn't it?

With that in mind is a cam and lifter wear more likely on ratio rocker cams?

Thanks for posting your proposed combo JVL. Tell us why this would have been your choice.

Perhaps I can kick things off with a couple of questions:
1. My heads are 40 x 35. Would a 2mm bigger exhaust valve make much difference?
2. What lift and duration is that bugpack camshaft and what lifters were you going to use? I like bugpak valve springs but I got their street eliminators and matched manifolds but the ports didn't line up. The were 2mm to one side.
3.I don't know much about engines and especially strokers but would there be a rod clearence problem or rod ratio problem with such a big crank and standard rods?

Let's keep the combos coming but you need to explain your choice for interest not criticism.

CYA CT

Hi CT,choice factor....reliable and still pokie and torqure toget out of corners quicker....Q1Yes breathing is the key to anybetter performance using swivel feet with solids.....Q2not 100% 418lift 294dur (I will double check???? )scat lifters lighten....Q3machining will need to be done.....CT are you using chevy dual springs? if not buy them.JVLRacing

Hmmmm,i was thinking of staying out of this until i was a bit further along, BUT i just cant help myself,im gathering parts for a stroker ive got everything roughly priced at $9300,so far ive got a new mag case,new CB 82mm crank,DRLA 48 tri-jets with 40 vents,Mallory Unilite i havnt got the spring kit yet,and an 1 5/8 side facing header from A-1 should be sailing my way as we speak,so im into about $3000 with another 6-7 to go,theres no labour in these costs so machining and ballancing are additional.Anyway this is MY combo.
1. 2276 = 94 x 82
2.FK-8
3.42 x 37 AJs or DRD heads
4.9.5:1 comp
5.48 DRLA tri-jets 40 vents
6.1 5/8 side facing headers by A-1
7.CB 5.4" H beam rods with ARP 2000 bolts
8.Kennedy stage 1 with Daiken disc
9.CE straight cuts
10.H.D. alloy push rods
11.26mm Shadeck pump full flowed
12.Schubeck composite lifters
13.Mallory Unilite with spring kit
14.CB or Berg 1.4 ratio rockers
15.German flywheel lightened reground
16.36 horse doghouse shroud
17.Berg fan
18.Static ballanced pistons pins rings rods
19.Dynamically ballanced crank flywheel cluctch pulley gears.
So there u have it,should be all sitting on my bench end of 06,after that i need another $2400 for a Pro-street box,steady fellas i bruise easilly :kiss

[ Edited on 16-10-2005 by lugnuts ]

Bugpack 4063-10 adv dur 296',dur at 0.050 268' lift at valve 0.430,its eqiv to an engle 130 with .030 less lift.:thumb

Bugger I just wrote a long post and it was deleted by my cat walking on the keyboard. Is that bad luck?

Briefly I wrote:

Nice combo lugnuts. I hope the expense pays off and you get it right first time. Jak's 2276 K8 engine was impressive but it really needed the heads you're going to put on yours.

Tell me about the shubeks and the Mallory.

JVL, don't give me the generic "breathe better line". Do you think with all else being equal that a 1.5mm increase in exhaust valve diameter would increase horsepower like it theoretically would on the inlet side? Remember at the start of the post I mentioned that i got more HP out of 40mm inlets than 44s.

That bugpak cam might work well in my engine (next time). My DRD heads are good for .450 to .500 lift and the bugpak cam would get .488 with 1.25:1 rockers. The webcam was .460 with 1.1s and .520 with 1.25s. I checked this but it came close to coil bind. That's why they suggested up to .500 with the descripiton on the heads. Do bugpak do matching lifters?

Why does everything seem to be a variation of an engle cam?

CYA CT

Hi,well what can i say, Mallory bit disappointed in the quality the pin in the shafts a bit loose timing will wander unless i go oversize onit,the rest is just what ive heard adjustable advance start and stop with diff advance curves available through the use of diff springs in the spring kit,grey and grey are supposed to be the go.Lifters well there an extravagance on my part,brought about through all the diff flat cam and lifter stories on STF and Callook forums,dosnt seem like theres a pattern to the failures all kinds of cams and lifters and spring pressures as well as run in procedures even the SLR treated lifters can wipe out,so this is my answer to the problem it has no guarantee to work either but its the best i can do,its recommended to bush the lifter bores in a mag case before running ceramics but i think ile try without first and if it gets noisey i can always pullit and bush it,if u have an alluminium case bushing is not needed,OR SO IVE HEARD.Will be getting a bung installed on my header for an oxygen sensor,should make dialling it in much easier when i get my O2 meter :thumb http://www.schubeckracing.com/mushroomlifters.html  http://www.lnengineering.com/lifters.htm  :kiss

[ Edited on 16-10-2005 by lugnuts ]

[ Edited on 16-10-2005 by lugnuts ]

CT,Lets answer a question with a ???You run a 69 crank...and used 44s inlets and ran backwards is that correct!!! ...next combo you run a 69 crank....and used 40s inlets and made better hps is that correct!!!.....So if you use 82 crank using 44s ....think of a steam train the more fire you feed it the better it goes....is that a better line to feed you....I might be a little out of my depth herr on this subject but i can see what is happening with combos.JVLRacing:P

[ Edited on 16/10/2005 by jvl054 ]

alarger exhaust valve won't make much difference but small HP gains @the top at the expense of some torque.

Hi CT

I was very dissapointed with Malory quailty years ago, I guess things havent got better. The lifter bores are eary to clearnace at home with a big burr in your handrill, its one of the many things you check before you do the final clean before assembly.

Steve

Hi JVL,

I agree that bigger valves are probably suited to a bigger engine and indeed a longer a stroke. My 44 mm valves were not only shrouded by the cylinder wall but the cambers really did need some work. The only machining they really had was from the tool that inserted the seats!

I think or theorise that air speed, or as astro put's it 'velocity', is crucial. That's one of the principles carbs work on.

Thanks for the "hand tools at home" handy hint Steve. I guess the lifters don't actually seat against the surface of the lifter bore so it wouldn't have to be perfectly square! What does a bur look like? Nice sig-line by the way.

One question for the engine gurus. When do your replace rod bolts? I think one of my rods is a bit tight and I'm going to order new bearings of the lot, should I order new rod bolts? Thanks.

CYA CT

Your right CT, big is not always better..................although some girls beg the differ...............lol.

My theory is keep it simple. I even run a standard flywheel, points and non ported heads, and still get good results. So why spend all this extra dosh on what would inevitably be only a little gain. Your last combo sounded like a reliable combo that produced good hp so why not go back.

I have spent thousands over the years chasing hp in my rally and race cars with very little rewards......The only rewards I really got were the broken cranks and rods I have hanging as trophies on the garage walls.

The reason for bigger cc ratings is pretty simple, for a given combination you make the same power but at a lesser RPM. You churn more ccs of fuel/ air mix per minute for a given rpm in a 2276 than you do in a 1915.

... and at the same RPM the shorter stroke is doing it with less stress on the reciprocating parts.

A 69mm stroke will rev to over 7000, all day every day, ....

if an 82mm stroke does this, something will eventually give.

How many broken 69mm cranks have you seen destroy engines compared to stoker engine failures. Even Okrassa strokers eventually break.

Hi Nathan,

I think that a $2000 stock 1600 with 40 RWHP is good value because it's $50 per horsepower. From that point I think it costs on average $80 to $100 per horsepower and all the labour is free.

That means lugnuts engine should have between 110 and 130 RWHP.

Are your heads street eliminators? These are good on 1915s providing the compression is high and you stick with 40 or 42mm vinlet alves and clean up the chambers. People complain they run hot but I didn't find them too bad.

Hi 56 Astro,

Can you be constructive in disussing parts or pass on your engine building experience rather than preach your (or somebody else's) theories? I'm not meaning to offend but I find the above comment pointless in this thread.

CYA CT