Possible L-35 ID

BMFB

BMFB

Not to scale
Alright, so i was rummaging through my local J yard found a set of these for 30 bucks. Pulled them off, looking only at the PN. Now, I'm reading on here a bit and it turns out I may or may not have a desirable set of heads. I see something about throat angle having something to do with them, but I am unsure of where this measurement is taken precisely. I know from these pics you won;t be able to tell much, but I figure anything can be a clue.

heads01.jpg


heads1.jpg


heasd2.jpg


I realize they don;t have the screw in rocker studs, which is what I noticed first. If they are the wrong heads I can always swap them, but it just will take more time. I have no idea what they are off of other then a balance shaft motor that was in a pile of other motors.
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

that is indeed the casting number (upside down, sorry) but I;ve read:

The 10077626, 14099064, 10240209 or 10238181 castings were used, but be sure to check them over carefully because there are two versions of the 10238181 and 10240209 castings with an important difference. In '92 and '93, they came with an 8° top angle on the intake seat and a 75° throat, but that was changed to a 30° top angle with an 80° throat in '94. Separate the 8° heads from the 30° heads and use them only on the '92 and '93 engines.

frankly, I don't understand how to check, and I'm not sure why it matters. Furthermore, I am not sure which set of heads I'm supposed to use on a 92-93 engine, the 8 or the 30. I duess I dont see what the difference is yet
 
Beavis

Beavis

Still plays with trucks
Re: Possible L-35 ID

If you can find a set with screw in studs that should be the one with the better throat design. Probably off a 93 or 94
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

"Both the 10238181 and 10240209 castings were used, but they have to be visually sorted because the early ones with the 8° seat probably shouldn’t be used on the ’94s and ’95s. If you do decide to stretch the rules and use the ’93 heads on a ’94-’95 engine, be sure to use them in pairs. Some of the ’94s still had adjustable rockers because Romulus didn’t switch over to "net lash" until ’95."

So, according to "the holy grail of 4.3 info" I have an ultra rare set of 94 L-35 heads with adjustable rockers from Romulus. Also, this clarifies that I should be able to use either head on a 92 motor, (which I think all sytys are) as long as I don't put them on a 94 and up motor. I guess the 94 and up heads have the 'better' throat angle that I still don't understand fully. Only real bitch now is that I didn't find the push rods or rocker arms, I wonder if the ones I have now will fit, at least they're adjustable I suppose....
 
Beavis

Beavis

Still plays with trucks
Re: Possible L-35 ID

Quadrajet72 said:
Those are L35 heads. Interesting they don't have the screw in studs. The intake eye-brows and the fact they are on a balance shaft block, makes them L35's. All L35 from 92-95 are balance-shaft engines.

Don't get all side-tracked and confused by the "throat angle" thing. Either of the angles will bolt onto any block. The recommendation to "sort them, and keep them on the correct years" is to avoid any driveability issues with having potentially different airflow characteristics on each head. If both heads are the same, it doesn't matter, IMO. I'm not sure it would matter if they were mixed, either.

In this pic, the casting DATE is just above the casting number. It looks like L19x where the "x" is the year. I can't make it out, but could be a "1". L19 = December 19. So if it's L191, Those would be very early L35 heads and engine originally installed in an early production 1992 model-year vehicle.
heads01.jpg


Those look pretty hammered, but for $30.00 they're worth the gamble they aren't cracked. If you have never done so, put an L35 head alongside a stock SyTy (LB4) head, and remove an intake valve from each. Compare the ports from the valve-side. Until you do this, and see the difference for yourself, you can't understand why these heads are so cool.

DaveP

Once you SEE the difference for yourself, you have to have them.
Click to expand...

When i put my l35's side by side to my lb4's, and stuck my finger down in the intake runners I noticed a big differance in width and subsuquently flow. It's no shock after seeing/feeling them inside why they are a great cheap upgrade. Also, they have proven they can make good power as quite a few have taken them pretty far.
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

I cleaned them up a bit and it looks like it says L158, but its not well cast...
 
Beavis

Beavis

Still plays with trucks
Re: Possible L-35 ID

Any decent head shop will tell you what you need and make good suggestions. Your going to get them "freshened up" anyways. You can get some cheap roller rockers with locks for under $175 and roller tips for even less. If you are on a tight budget, then stamped steels are the cheapest. but if you can....less friction makes for better efficiency and power and rpm range. So I've been told.....
 
It's just a six

It's just a six

Super Member
Re: Possible L-35 ID

IMHO,
I would not worry about the different throat angles as a good cyl head shop can change the throat angle to what ever works best for max CFM.

I would have to ask my friend to see what throat angle works best for those types of Chevy heads.

I am pretty sure there are a couple combinations that will work good.

Angles, seat widths, throats,, all play a major role in making a head flow good or just so-so.

You can lose 10-30 CFM roughly from getting any of the angles, seat widths, throats incorrect.

Heck, having a valve seat width too wide by .010 can drop 10 CFM.

That's why I always say, if you dont know what your doing,have a cyl head shop that knows what they are doing, do the work for you.

Speaking of which, did you guys see HP TV today about porting heads?

For what they did on those heads, they will not gain much of any improvement, ok for a guy that does not want to make a major improvement or does not have the $$ to make alot more power.

Also the comparision of buying an aftermarket aluminum cyl head for $1000 dollars,,, there would be no comparision on the HP & TQ output of most any aftermarket heads will produce as compared to those cast iron junkers.

If you were to take those cast iron heads to a shop, street strip port,comp valve job,screw in studs etc, you will have close to a $1000 dollars (roughly) into them & they still will not flow as good,, plus, if the cast iron heads break a valve & blow out a chamber,or crack somewhere,, well lets just say you might as well throw that one away(most likely) , aluminum is easier to repair than cast iron.

Dont get me wrong, cast iron heads are fine to use, & for some cases , the more affordable & easier to use option.

I am just saying,, don't think that HP TV show on how to port your heads shows all you need to know how to port.
There are books, & if you have any cyl head shops by you to look @ good ported heads do it, pics in books does not show all either, it's necessary to actually feel & see the contours of short turn radius', bowl ares etc.

Got carried away, sorry.:oops:
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

I got the heads for 30, I can get them milled for about 80, and a valve job for close to the same. I don't really need roller tipped rockers, stock stamped will do fine, I'm not running a radical lift, nor a radical RPM, under 5k. the stock studs that are in there will do great, as long as they will work with the other stuff i got, need to check that still... Now when I say doing my own port work, I don't mean going all out, I mean more just taking the burs off, and other casting errors, I'm not gonna be really cutting any metal. Hot tanking and mag fluxing i'm not sure on cost, but i would guess under 150 bucks. So for 330 (pending all valves are straight) I can have a much better flowing set of heads then stock, springs I'm not to worried about, although if it comes down to it ill spend 60 bucks and get new ones, maybe ill even get lucky and the springs off my LB-4's will fit (fat chance).

If I was building a super performer, then i would go the higher end head rought, but i'm not, I understand where your coming from, and I see that the higher inital cost, although daunting, can actually be a better deal in the long run (although, where am I gonna get a set a lil' brodies anymore at the drop of a hat) This is a pretty mild build. still a stock turbo (hunting for a 20G) and stock cam.

upon second inspection, it could be a 3.
 
Beavis

Beavis

Still plays with trucks
Re: Possible L-35 ID

Look into Comp cams direct stock replacement components. You will be surprised on how much that stuff will wake that truck up and you wont even have to do anything other than freshening them up with new seals and such. I understand what you are trying to do, but a couple of extra $ in the right areas will do wonders.
 
H

Hongkongtyphooey

New member
Re: Possible L-35 ID

I think there's a thread about these on here called 'Kinugawa feedback' but I've not read it yet. The 20G is supposed to be 400hp and they do a 450hp Garret 60-1 too. Might be gearbox upgrades required though, if not more parts. Saw a nice carbon fibre driveshaft in Waller's ebay shop. ;) These links are for the two turbos.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290544702344&ssPageName=STRK:MEWAX:IT

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290544702486&ssPageName=STRK:MEWAX:IT
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

I was planning on having the valves and seats done, guides replaced, as well as some mill work done to cut a smooth face onto the head.

as for the springs I'm not sure what I'm gonna do yet, I'm gonna see if the springs I have now will work on these different heads, if not Ill have to grab a pair

perhaps going to a 1.6 to one would be beneficial on the rockers, now that I can actually flow a bit more, although i'm not sure of what all would have to be done the clearancing for the push rods, but otherwise I was thinking of sticking with stock stamped. the friction of a stamped non roller rocker seem...exaggerated, am I wrong? I mean, I don't have high left or run over 5k rpm, this seems like a waste of money, unless I go to a 1.6:1rocker. any suggestions on that idea?

The rest of the motor has been just rebuilt (eagle rods, 8.7:1 forged pistons, scat crank, mill work on black and old heads, new lifters and springs, stock cam reused) but apparently my TC couldn't take the new found power, and balooned, taking out my thrust bearing. so while I have the motor apart again, I decided this might be a nice thing to do.
 
It's just a six

It's just a six

Super Member
Re: Possible L-35 ID

Hongkongtyphooey said:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290544702486&ssPageName=STRK:MEWAX:IT
Click to expand...

I have not looked for this on the UK Ebay, I have just been posting parts to put together, here is what I was really wanting to find, good job Hongkongtyphooey looks like a good deal for a direct bolt on unit & also has the smaller 12 CM housing,,,, maybe those guys making these turbos listen to us on this forum on what size turbine housing to use for stock converter etc.

12 CM is the absolute biggest A/R for the turbine housing you can use w/a stock torque converter & still be able to boost it w/a brake launch. : Note must have good to great flowing exhaust system.

Also, as far as roller rockers are concerened, I would through those on also since you are going through the heads.

It's not just have to go w/ bigger lift cams, higher spring tension etc, roller tip rockers will give you more accurate valve lift, less wear on your valve guides,( there rolling on the tip of the valve stems instead of pushing & sliding.

Stock stamped rockers are inaccurate in ratios, you can have one rocker have a ratio of 1.4, next one 1.45 etc, while the aftermarket rockers are supposed to be more accurate in there ratios.:tup:

IIRC, Kenne Bell used 1.6 ratio rockes w/no other mods, they just drop right in? Correct me if I'm wrong guys.

The biggest gains to head porting are in the bowl areas, short turn radius, & opening up the bottleneck in the intake port. A lot of companies will port only up to roughly 1" into the intake port,that is not far enough in to open up the bottleneck.
Intake manifold to intake port maching is good to do also & most people can do that fairly easy, but it does take practice & patience.
 
Last edited:
WyoSyclone

WyoSyclone

Active member
Re: Possible L-35 ID

BMFB said:
Alright, so i was rummaging through my local J yard found a set of these for 30 bucks. Pulled them off, looking only at the PN. Now, I'm reading on here a bit and it turns out I may or may not have a desirable set of heads. I see something about throat angle having something to do with them, but I am unsure of where this measurement is taken precisely. I know from these pics you won;t be able to tell much, but I figure anything can be a clue.

heads01.jpg


heads1.jpg


heasd2.jpg


I realize they don;t have the screw in rocker studs, which is what I noticed first. If they are the wrong heads I can always swap them, but it just will take more time. I have no idea what they are off of other then a balance shaft motor that was in a pile of other motors.
Click to expand...


that's a strange set of heads. According to GM they never made the 181's with press-in studs. Like another member said, they must be a very early production set.
181's were only produced from 93 thru 95.
The only documentation where GM does not specifically list srew-in studs on a pair of 181's is on the 92 Z block, Romulus, without balance shafts, 10 bolt metal timing cover, and without transmission strut boss on block. Apparently they started using them late '92 in advance of the '93 production runs.
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Possible L-35 ID

You will have no problem with 1.6 rr with stock springs and cam, as long they are good condition I wouldn't spend my money on new springs unless you are adding an aftermarket cam.
 
BMFB

BMFB

Not to scale
Re: Possible L-35 ID

alright, I may have to look more into a set of 1:6 rockers for these, I don;t recall them being to expensive.

Yea, I figured these were goofy heads, did come off a balance shaft motor too. I just hope they're ok as far as cracks go.

I have been hearing strange things about that ebay company, is that really a good turbo that I'm not gonna hate, or isn't gonna grenade on me? I remember hearing that a 10cm housing is what you want, but with my build and needing a new tc is this 12cm something I should look into? if so, what should my new stall speed be around?
 
Beavis

Beavis

Still plays with trucks
Re: Possible L-35 ID

A 2800 rpm stall will be fine whether it's a stock 8 or the bigger 12cm.on a stock turbo it will probably stall at 2600-2700. On my 12cm 20g, my 2800 Precision stalls against the brakes at 3000-3100. If you want a decent cheap upgraded tc, look for/into the early 90's corvette one. There should be some more info on it somewhere on the board here.
 
It's just a six

It's just a six

Super Member
Re: Possible L-35 ID

IMO,
if you want to keep somewhat decent mileage, you do not go to a higher stall than what is needed.

With that Ebay turbo specs,you should get a minimum of 2400 max of 2600 stall should work nicely.

The specs on my turbo are the same as mine.

http://www.syty.net/forums/showthread.php?t=53545

As far as that Co on Ebay selling good or bad stuff,they seem to have good feedback.

A member here bought a 20G turbo & cannot get more than 10-11 psi of boost.
I would think if he would contact the seller they would most likely give him another one in exchange.
 
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