TheSamba.com :: View topic - Which cylinder heads? CB, Mofoco, Steve Tims, others?

Tue Mar 10, 2020 10:53 am

Roy is suggesting that I use a 40x35.5 head for my engine build. Will that get me to my planned 150hp using an Engle FK8, 1.4 rockers, approx 9-9.5:1 compression ratio? The carbs will probably be the Weber 44 IDF.
Thanks again for all of the input.

Tue Mar 10, 2020 10:59 am

Yes. 2161, ported 40X35 heads, FK-8 w/1.4, 9.5, dual 44 IDF, & 1 5/8" exhaust can get 150 HP, and be a very street friendly engine.

Tue Mar 10, 2020 11:04 am

pamchuck wrote: Roy is suggesting that I use a 40x35.5 head for my engine build. Will that get me to my planned 150hp using an Engle FK8, 1.4 rockers, approx 9-9.5:1 compression ratio? The carbs will probably be the Weber 44 IDF.
Thanks again for all of the input.

Yep, I played with the dub dyno and going to 42 x 37.5 valves makes the HP and Torque go down with that cam, rocker and carb set up.

Tue Mar 10, 2020 2:21 pm

Alstrup wrote: Nothing will withstand serius valve float or serius detonation. But 90% ot the issues with "stretched" stems are down to the fact that the valve locks are not matched to the valve. bingo... also many people think the groove should hold the valve... the flat portion is what holds the valve stem, the grooves locate it when the keepers are gaped as they should be in performance apps,. thus single groove holds better with more stem contact. the taper gives the force to hold the stem.floating keepers just wear parts. if roy took the time to fix all the keepers he uses he would not have much time for a lot of any thing else. or hire somebody to do it right and raise the prices.probably not going to hapoen.. valve adjustment has squat to do with the wear associated with keeper grove wear on floating keepers.but thats a argument for another tyme. floating keepers are just fine for week springs & stock/mild cam most of the time. Detonation is a killer of many parts. from bearings to lifters,pushrods,rockers,keepers,valves, pistons,gaskets...pockets and more.

Wed Mar 11, 2020 3:47 am

pamchuck wrote: Roy is suggesting that I use a 40x35.5 head for my engine build. Will that get me to my planned 150hp using an Engle FK8, 1.4 rockers, approx 9-9.5:1 compression ratio? The carbs will probably be the Weber 44 IDF.
Thanks again for all of the input.

Yes my 2110 had 40x35.5 heads, 44’s and an fk8, made 160 had was a dream to drive.

Wed Mar 11, 2020 5:26 am

RacerDave...

To build a 2161 do you need a HighTop Case for a good long lasting engine or can you get away with a OEM? Just thinking of the 84 Stroke...

Or, how would you build? RB

Wed Mar 11, 2020 8:01 am

RailBoy wrote: RacerDave...

To build a 2161 do you need a HighTop Case for a good long lasting engine or can you get away with a OEM? Just thinking of the 84 Stroke...

Or, how would you build? RB

People use OEM for larger cranks. I'm doing a 2180 (82x92) build right now with an original german AS41 case from 1971 and a 82mm crankshaft.

I think the consesus is that you need ( or at least want ) a later 71+ engine case because it is dual oil relief. But once you clearance it, check for cracks, do the machine work it will work perfectly fine for up to an 86mm crank atleast.

Wed Mar 11, 2020 11:29 am

RailBoy wrote: RacerDave...

To build a 2161 do you need a HighTop Case for a good long lasting engine or can you get away with a OEM? Just thinking of the 84 Stroke...

Or, how would you build? RB

I wouldn't build a 2161. A 2110 is the largest I would build with 90.5mm pistons.

For a long lasting street engine 82mm crank is the largest I would use. Greed is the only reason to stretch your dick longer. For a street engine I would use a OEM case. All the bubble top cases require you to clearance the factory sheet metal and fan shroud to fit and cool correctly. 84mm stroke engines are wider and harder to fit into a Bug engine compartment. Wider engines also leave gaps in the engine tin causing cooling issues.

For a long lasting street engine I'd build a 2180. If you can live with 40K mile engine life than build a 2276. Going any bigger will only produce minimal results. For example a 2332 may only produce 3-4 more HP than a 2276. When you have 165 HP, how much more are you really going to notice 169 HP?

There have been racers build 88X95 race engines in a factory Magnesium case, It would require extensive machine work.

Wed Mar 11, 2020 12:23 pm

I would not waste the time$ money on a mag case for a 84&up crank.

Wed Mar 11, 2020 1:05 pm

vwracerdave wrote: RailBoy wrote: RacerDave...

To build a 2161 do you need a HighTop Case for a good long lasting engine or can you get away with a OEM? Just thinking of the 84 Stroke...

Or, how would you build? RB

I wouldn't build a 2161. A 2110 is the largest I would build with 90.5mm pistons.

For a long lasting street engine 82mm crank is the largest I would use. Greed is the only reason to stretch your dick longer. For a street engine I would use a OEM case. All the bubble top cases require you to clearance the factory sheet metal and fan shroud to fit and cool correctly. 84mm stroke engines are wider and harder to fit into a Bug engine compartment. Wider engines also leave gaps in the engine tin causing cooling issues.

For a long lasting street engine I'd build a 2180. If you can live with 40K mile engine life than build a 2276. Going any bigger will only produce minimal results. For example a 2332 may only produce 3-4 more HP than a 2276. When you have 165 HP, how much more are you really going to notice 169 HP?

There have been racers build 88X95 race engines in a factory Magnesium case, It would require extensive machine work.

Yes, yes, and yes to literally every word of this response.

Thu Jan 02, 2025 10:16 am

Are OE by FPD heads anygood? New to volkswagons.

Thu Jan 02, 2025 11:39 am

ACVW is the first engine that I have modified with so damn many cylinder head choices available. It is too confusing and I have serious doubts about the accuracy of the claimed flow numbers. I am not saying that all inaccurate numbers are stated on purpose even though some may be. In my case I gave up and my local head guy is going to port a pair of 502 heads. I haven't seen too many suppliers of totally bare heads which allows me to use top shelf seats, guides, valves, springs, and retainers. Who have I missed?

What specs of flow and valve sizes should the OP be shooting for to get his 150hp?

Thu Jan 02, 2025 11:45 am

Bulbtr wrote: Are OE by FPD heads anygood? New to volkswagons.

This is an almost 5 year old post. What are you looking for?

Do you need a bone stock replacement head, or are you looking for a performance head? Since you are new to VW's, you should list what you are planning to build, and then we can lead you in the right direction.

I have never used the OE brand heads, but I would guess they are just a typical cheap replacement?

Lots of options. Some good, some really bad, but they are mostly all application specific.

Brian

Thu Jan 02, 2025 5:49 pm

Yes case is at machine shop getting work to build 1835 and it will have scat 35 cam. Thats where I am as of now. For as the carbs I have dual solex 40/44. Guy doing work sells heads thats just an option he has was just curious with so many options was that a good choice.

Thu Jan 02, 2025 7:20 pm

Lightly ported stock valve heads with a good valve job will outperform off the shelf 40x35 heads.

For what you are building, a set of Tims 37x32 heads would be great.

If you can get out of that c35 cam, I would do it. An 1835 with kadronS is begging for a 218/119 cam.

Brian

Thu Jan 02, 2025 8:16 pm

You do not like the c35 or are you saying its just not right size? Had thought about going single progressive carb.

Thu Jan 02, 2025 10:34 pm

Bulbtr wrote: You do not like the c35 or are you saying its just not right size? Had thought about going single progressive carb.

Both.

Usually the camshaft is the very LAST part you pick. You need to know what the heads will flow, what exhaust you want, and the intake before you can figure out what cam will make the engine do what you want.

Make sure you read the “how to make a progressive work” thread before you spend your money on one.

Don’t be afraid of dual carbs. There are multiple reasons why they are far more popular.

Why don’t you tell us what you plan to do with the engine, what it’s going in, your driving style, expected HP, budget, etc. Then hopefully we can get you headed on the right track BEFORE you go ordering a bunch of mismatched parts.

Brian

Fri Jan 03, 2025 7:14 am

So it was a 1600 with the dual carbs. About 4 months after I bought it a valve spring broke and cause some damage. So removed engine and looking through engine rebuild book was talking about measuring this and that and line bori g so I took it in for machine work. Well line bore was only $60 and just said I may go to 1641 but heard a 1835 running and really liked it so decided to go that route with machine costs not being much. Was told that engine had a scat35 and it had a double barell progressive carb. Im good with the double kardons if it would still sound like the one I heard. Will just drive it atroynd on weekends and shows in my area. Also drive to work some. Budget posdibly $1500.

Fri Jan 03, 2025 11:50 am

Brian_e wrote: Lightly ported stock valve heads with a good valve job will outperform off the shelf 40x35 heads.

For what you are building, a set of Tims 37x32 heads would be great.

If you can get out of that c35 cam, I would do it. An 1835 with kadronS is begging for a 218/119 cam.

Brian

Thats an interesting split grind, do you have a cam card for that? I’d be interested in seeing the events. I never understand why so many vw cams, when they are split run less on the exhaust, considering the typical vw exhaust valve and port youd think theyd do the opposite, like Crower’s 61005.
Far as the C35 though, ive run them on several engines and have no complaints. i think its pretty run of the mill for that group of cams. I mean, for reference its damn near same duration as a 110, little less lift, and events are within a few degrees but C35 looks like it does everything a little later aside from opening the exhaust. Funny that all of scats “c” cams the intake & exhaust events are mirrored which seems like that’d say they didnt spend a lot of time designing these cams. if i was needing to buy a cam im partial to CB but if i had a C35 and on a budget then id use it.
Cam is definitely important but make sure you put some compression in that engine ( funny how many times thats been said today ). And how that 1835 you heard sounded will vary greatly depending on cam, compression, exhaust, and intake / carbs to some extent. So dont be disappointed if you dont nail the same sound with the same size engine. But you might!

Fri Jan 03, 2025 1:52 pm

BFB wrote: Thats an interesting split grind, do you have a cam card for that? I’d be interested in seeing the events. I never understand why so many vw cams, when they are split run less on the exhaust, considering the typical vw exhaust valve and port youd think theyd do the opposite, like Crower’s 61005.

Here is the card for a 218/119. Kick ass cam. Especially with single barrels.
https://webcamshafts.com/pages_vehicles/automobile/volkswagen_install_data/tc_000670_002743.html

The reason for the opposite split from typical v8's, is the VW exhaust port is overly efficient. Run a split duration to tame it down a bit, and help the intake keep up. On the flow bench you can really see it. It takes very little work to get a stock exhaust port to work really well. Not so easy with the intake. Ideally you want about a 75-78% E/I flow difference. The split cam and help get that ratio back in check.

The 42x37.5 heads could really use the split cams. Lots of those heads are up in the 88-92% E/I flow ratio. Nice fresh intake charge headed right out the tailpipe because the exhaust is too efficient.

T4 VW heads have the opposite problem. Super shitty exhaust ports, really good intake ports. They have split cams with bigger exhaust profiles.

I never understood the Crower cams.. Must not have been designed with head flow numbers at hand.

Brian