Just looking at a new engine for the beetle, its planned as a hot street/ mid race motor. The old 1776 is getting a bit long in the tooth, and it simply doesn’t have enough power for places like Mt Cotton. I have been talking to my engine builder and he is recommending a fk7 cam. He is working on using larger valves with a milder cam to lower cam train stress while getting better flow.

Don’t want to go into to much detail as I want to get the engine running and get some times, but basic specs are

Near on 2L
44intake, 38 ex valves
Limited to 6800 rpm
My carbs dell 40mm will be a restriction until I can get some bigger ones probably in 12months or so time.

With the possibility of going to bigger carbs later the options are

1- Go the fk8 maybe with 1.25 rockers and when I get the bigger carbs go to 1.4 rockers.
2- Go the fk7 with 1.4 rockers and stay that way
3- Go something like a w110 or 120 and go with some 1.25 rockers.

Does anybody have any experience with the fk7 and or fk8?

I currently run a w100 and find it comes on about 2500rpm up to about 5800 rpm. With mid worked std heads on a 1776 with dual 40mm dells.

the k8 is a good hard reving cam..currently run a 2.2 with a k8 which revs hard up to 7.5-8000 rpm with a set of 48's...heads are similar....i do rerly on the 2.0 torque down low to overcome less bottom end..rod lenght is another important isssue are you running std vw rods? what stroke crank and barrel piston combo..90's 92/94 ?..what weight is your car ? heavier than std hope some of this feed back can point you in the right direction cheers steve

yeah thats the sort of stuff i am after. I am after only about 7k rpm aboslute max, so maybe the fk8 is to high in the rev range. At the moment the 40mm dells will be the main restriction, so it would really restrict the fk8 if it revs to 8k. Rods are h beam, but leaving it up to my engine builder on length etc, who i trust pretty much, but i was just looking for opinions on what other ppl think. he said fk7, and he is probably right then about the fk8 being a little to big.

94 barrels, and sub 2L....

Stay away from the K8 with 1,4s. CB make a similar profile that is not as harsh on springs.
Although with a 6800 limiter you might not have any problems, but that thing comes on at over 3000 rpm so you might not like it.
I don't have any experience with the K7.
My favourite is the V26 and big rockers. (not VZ25!!!)

Thanks for that Dave. yeah i am sort of steering to the k7 as leon recomended it, and all the other engines he has built me have been really good. But i always ask for other opinions.

the only think that was pushing me towards the fk8 was the ability to run smaller rockers with the smaller carbs and then upgrade with the larger carbs later. I was also looking at the dyno sheets, in this section, and jak seemed to be running a similar spec engine, but with smaller valves and getting about the power and power band that i want with the k8.....

why is it so hard to choose....

[ Edited on 2-6-2006 by BiX ]

Jak's old 2275 was only held back by its heads. They were too tiny for the engine. They worked well on the 1880 which made over 90 hp. When it went out to 2275 the thing was very strong down low but struggled to breathe with those heads. A borrowed pair of 48idfs netted 10 more hp than the 45 dells. I think the heads were just cleaned up stock ports with bigger valves.

I think his final call was to buy the right heads or spend less than that on a Subaru motor.

CYA CT

Ct, thanks i think he had a combo there about 2017cc or so? thats is osr to what i am aiming for. The heads are cb wedge ports, so flow pretty well.

If i run teh k8 and run the bigger heads and bigger carbs will that move the power curve up the rpm scale compared to a engine with smaller heads?

the price is starting to scare me, but i still like the idea of being vw powered, form a hp per $ point of view its pretty bad

The main reason is i am building up for developing a 2L prc car, which means i have to stay vw powered, or buy a non vw eg gemini, escort and go that way, in which case a subi powered beetle is an option.

u should use a K10 , K8 is a mildish cam 4 an engine that size.

Those heads are good, go with the smaller cam...40mm carbs will limit the airflow anyway.

I was thinking about a FK10 with 1.25s but my valves wouldn't lift that high (Thanks for the help there by the way "dangerous"). In sticking with the non-ratio rocker philosophy I as going to go with the usual Engle 125 then at the last minute with some coaching I changed to the 130 which some say is the non-ratio rocker version of an FK10.

I thought the duration would make the car a pig at low revs. At first I thought I was right; then with a bit more tuning and an MSD it's now great down low. After using the old pobjoy steroid cam and a webcam 109 I'm really pleased with the 130.

I did a funny thing (well to me anyway) last friday night, before the private practice day at eastern creek. I was about to stop at a right hand turn arrow and then it turned green so I didn't need to stop. I rolled passed a new mini cooper which seemed to object to being passed by a 1956 beetle. He put the boot into the mini so I did the same.The bug felt a bit off and slow to rev but it was still pulling. This started at about 20 - 30 kmph so it was pretty lame.

I was at the mini's rear quarter and gaining on him inch by inch which felt really strange. I couldn't quite understand why the car was pulling so slowly. I thought it must really be weighted down by all the tools and junk I take to the track. I could hear the mini revving it's ring off and I wondered why my hand was on the gear stick and I hadn't changed gear. Then the mini changed gear and fell back a car length then promptly backed off.

At this point my car was just starting to feel alive. Doing about a hundred and coming up to a speed camera I coasted in great confusion over what had just happened. After about 5 minutes I figured it out. I was in third gear when I thought I was in second. The engine pulled from about 20 kmph to 100 kmph in one gear. Who would've thought you could do that with an engle 130. Well not me.

CYA CT

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[ Edited on 2-6-06 by dumone ]

Ok bringing up this old thread, but having been talking about a few things in the tech section and it was getting a little OT.

Ok well anyway, the FK8 seems to be out the door as an option, my engine builder says it has harmonic issues, and dangerous seemed to back that up.

This engine is being built for a general club car, eg mainly autocross, hillclimb, motokhana with the aim of going into rally. Dropping a little top end is not a problem if i am gaining torque.

So options are

fk7- with 244 duration at 0.050", and 0.499" lift with 1.4:1 rockers
Tighe cams 148A - 253 duration at 0.050", 0.509"lift with 1.4:1 rockers
tighe cams 149A - 263 duration at 0.050", 0.500" lift with 1.4:1rockers

The engine will be a slightly stroked 1915 (eg 2000cc), with wedge ports, the idea was to use bigger heads rather than smaller, but less valve lift to reduce valve train stress/issues.

From my research,

1. greater duration will move the power band up the rev range?
2. greater lift will allow more airflow and therefore higher potential power?

Does anybody have any comments on the cam, any idea what power band a duration of 253 will produce?

I know its a multifaceted approach and there are many variables...

Both those Tighe cams are better without the rockers,
although they say you can use them with ratio rockers,
I am unfamiliar with their lift rates.
I heard the 148A was a noisy profile, but they may have addressed that issue.
I think Stan is a fan of those profiles using VW rockers, and his results are well known.
The V26 has 254@.050 and is what I would use if you have ratio rockers.
I think the Engle W120(or 125) has similar timing@.050", if you want to use stock ratio rockers.
Anything aroung 250 to 255@.050 will be nice to drive,
and produce fantastic power with those heads..

What brand is the V26?

Engle.
You can get it through Bergs as GB309E I think.

im no expert engine builder, but 44 intake valves on just over a 2l engine seem to big maybe unless you have bigger carbs and high lift long duration cam to make use of the flow.

like that volkmen art bloke says, you should build an engine around what your heads can flow.

im looking at building a 1916 similar to what you are after bix?

are you using 44 intake on heads?

although i am going to be using 42x37.5 heads.

Anthony

Im running the CB equivalent of a k8, and have run a web 86b which is pretty much a clone in numbers.

The web was in a 2110 with 42 x 37.5 Oval port CNC heads. It was disappointing. The CB cam in a 2276 with handported 44 x 37.5 heads, ported for te car weight and gearing pulls from start to finish (about 7k). Its not on and off at all.

The head, car weight and gearing combo sucked in the 2110 combo.

Both engines had 48mm dells on them and 1.4:1 CB rockers.

We have used the CB version of a K8 and found it to be good as far as harmonic issues.
With large port heads like BiX is planning, and smaller capacity, it will "come on" above 3000.
BiX needs something in the mid 250's @.050".

I assume your talking about the eagle cams CB has? Might have to investigate those some more, and have a talk to Leon.

After a little more research, going with an engle 120, with 1.25:1 rockers. the lift is 0.004" less than the Fk7, but the duration is 253@ 0.050"

Its all starting to come together the rods are here, all the little bits (rockers etc) have arrived, not just waiting on heads, case and crank!

How's the engine building going?

http://forums.aussieveedubbers.com/viewtopic.php?tid=61448&page=1#pid581713