L35 VS LB4 head pics

[QuinnSY]

I got my L35 heads in the mail a couple days ago, and figured I would take comparison pics of the two since I haven't seen any. I'm also curious if any one has flowed both the LB4 and the L35's to see what the flow gains are of the 35's.

Through all the pics the L35's are on the left.

 

[It's just a six]

Re: L35 VS LB4 head pics

Great pics!

If you can,somehow take pics of the intake ports of both heads w/good lighting,so people can actually see how restrictive the stock heads are.
Thanks:tup:

 

[djwaggoner]

Re: L35 VS LB4 head pics

VERY helpful...knowing what differences to look for makes finding it much more likely!
The JY guys _may_ not be reliable...LOL

 

[QuinnSY]

Re: L35 VS LB4 head pics

Great pics!

If you can,somehow take pics of the intake ports of both heads w/good lighting,so people can actually see how restrictive the stock heads are.
Thanks:tup:

I'll try to get those pic next time I visit my machinist. Is that the biggest Difference with the L35 heads? a lot more flow, but about the same volume. all the ports appeared to be about the same size, but noticed the curves inside are a little different.

I have been pondering about weather or not to get both sets flowed to see the true difference between the two. Also noticed that the rocker studs on the L35's are screw in over push in! :tup:

 

[It's just a six]

Re: L35 VS LB4 head pics

I'll try to get those pic next time I visit my machinist. Is that the biggest Difference with the L35 heads? a lot more flow, but about the same volume. all the ports appeared to be about the same size, but noticed the curves inside are a little different.

I have been pondering about weather or not to get both sets flowed to see the true difference between the two. Also noticed that the rocker studs on the L35's are screw in over push in! :tup:

Mostly a lot more airflow.
The LB4's have the intake port window extreamly downsized further in the port becuase of the high swirl vane obstruction right in the port..:tdown:

I believe these type of heads (V-6 & V-8) are the worst flowing SBC heads ever produced. I believe the same heads the same style used on 1988-1995 SBC truck heads.

 

[turboluke]

Re: L35 VS LB4 head pics

good info Thanks

 

[92AcademyPhooner]

Re: L35 VS LB4 head pics

I would definitely be interested in what those flow numbers come out to be for both the LB4s and L35s. Good luck with them Quinnster.

 

[Throws]

Re: L35 VS LB4 head pics

I would definitely be interested in what those flow numbers come out to be for both the LB4s and L35s. Good luck with them Quinnster.

You do realize this thread is over two years old, right?

-P

 

[Quickstop [UK]]

Re: L35 VS LB4 head pics

Shame - those flow numbers would be useful/interesting!

 

[WyoSyclone]

Re: L35 VS LB4 head pics

Not sure if this link will work, or not... it's the excel spreadsheet I put together for heads.

http://r.b5z.net/i/u/10053520/f/4.3_Cylinder_head_application_guide.pdf

If it doesn't work, go here and look at the 'cylinder head digest' towards the bottom of the screen.

http://www.zddppluscentral.com/faq


I've been trying to get an L35 head option together for guys for a year now.... my machinist really let me down

 

[92AcademyPhooner]

Re: L35 VS LB4 head pics

Not sure if this link will work, or not... it's the excel spreadsheet I put together for heads.

http://r.b5z.net/i/u/10053520/f/4.3_Cylinder_head_application_guide.pdf

If it doesn't work, go here and look at the 'cylinder head digest' towards the bottom of the screen.

http://www.zddppluscentral.com/faq


I've been trying to get an L35 head option together for guys for a year now.... my machinist really let me down

Ok sounds good. Sorry about not realizing how old this thread was ha . I'll start being more situationally aware next time. But, yeah, thanks for the update. I'm looking into switching to L35s so this stuff will help.

 

[Throws]

Re: L35 VS LB4 head pics

Not sure if this link will work, or not... it's the excel spreadsheet I put together for heads.

http://r.b5z.net/i/u/10053520/f/4.3_Cylinder_head_application_guide.pdf

If it doesn't work, go here and look at the 'cylinder head digest' towards the bottom of the screen.

http://www.zddppluscentral.com/faq


I've been trying to get an L35 head option together for guys for a year now.... my machinist really let me down

I need to talk to you about this sometime. I'm picking up a set of L35s tomorrow and I'm going to start getting valves/springs/rockers/pushrods/etc together and I wanted to see what your goals were... I mean, I want Vortec power, without the Vortec cost.

-P

 

[dgoodhue]

Re: L35 VS LB4 head pics

I need to talk to you about this sometime. I'm picking up a set of L35s tomorrow and I'm going to start getting valves/springs/rockers/pushrods/etc together and I wanted to see what your goals were... I mean, I want Vortec power, without the Vortec cost.

-P

L35 flow low 170's on the intake side which about 10% more than LB4's (high 150's). Vortec flow mid 220's. I bet the average big valve l35 with quick port job most machine shop do flows less than stock Vortecs. From my sbc experience, I would guess a good porter would easily get 250 cfm out of a set of L35's, but the time needed to port iron heads is not going be cheap.

 

[Throws]

Re: L35 VS LB4 head pics

L35 flow low 170's on the intake side which about 10% more than LB4's (high 150's). Vortec flow mid 220's. I bet the average big valve l35 with quick port job most machine shop do flows less than stock Vortecs. From my sbc experience, I would guess a good porter would easily get 250 cfm out of a set of L35's, but the time needed to port iron heads is not going be cheap.

Do we have an idea of the CFM numbers for big-valved L35s? My worry about Vortecs is that (for me) the cost will creep out and I'l have $2000 into it when I'm said and done. I'm figuring $4-600 for L35s.

-P

 

[fivetodrive]

Re: L35 VS LB4 head pics

Not sure if this link will work, or not... it's the excel spreadsheet I put together for heads.

http://r.b5z.net/i/u/10053520/f/4.3_Cylinder_head_application_guide.pdf

If it doesn't work, go here and look at the 'cylinder head digest' towards the bottom of the screen.

http://www.zddppluscentral.com/faq


I've been trying to get an L35 head option together for guys for a year now.... my machinist really let me down

Which of these is better?

Vin code z 30 degree top intake seat angle. 80 degree TBI
or
Vin code w 8 degree top intake seat angle. 75degree throat. CPFI

I would assume the 80 and 30 since that is what they are on the vortec...

 

[Logan]

Re: L35 VS LB4 head pics

Random newbie question but do L35 heads bolt up the same as the LB4s or does the intake have to be modified?

 

[Throws]

Re: L35 VS LB4 head pics

Random newbie question but do L35 heads bolt up the same as the LB4s or does the intake have to be modified?

AFAIK: They are a "stock" replacement. No modifications needed. I have a set of L35s that I'm getting parts together for. Only thing I'm planning on is opening the valves on the exhaust side to 1.60 (leaving the stock intake @ 1.94).

-P

 

[Quickstop [UK]]

Re: L35 VS LB4 head pics

AFAIK: They are a "stock" replacement. No modifications needed. I have a set of L35s that I'm getting parts together for. Only thing I'm planning on is opening the valves on the exhaust side to 1.60 (leaving the stock intake @ 1.94).

-P

2 things that leap to mind...

Lots of them seem to be cracked from your experience in the junkyard so is that going to put them at more risk of cracking in future?

In the Tyclone thread that I hopefully linked to (Aaah fcuk it, here it is Tyclone vortec swap), the author mentioned that he didn't think that the enlarged exhaust/intake valves made tham much difference.

Good time to do any porting & polishing you want to do at this point, as well as get the valves ground, etc. Adding 2.02" & 1.60" valves will give very marginal improvement in breathing (if any), according to Fisher & Waar's book "How to Hotrod the SBC". 1996 valve sizes are 1.94" x 1.50"; really into less bang for the buck here (opinion totally my own).

Having read about other people cracking vortecs (I know you're talking L35s here), is it really going to benefit you?

Just a thought..

:2cents:

 

[Logan]

Re: L35 VS LB4 head pics

Thanks Throws. I appreciate the help. I am looking for a set now. Hopefully when I come back in December my Ty will be up and running.

 

[Throws]

Re: L35 VS LB4 head pics

2 things that leap to mind...

Lots of them seem to be cracked from your experience in the junkyard so is that going to put them at more risk of cracking in future?

I ended up finding a set that had previously had their seats replaced with hardened ones, eliminating the possibility of this happening in the future. My understanding with the L35s, is that you want to have the exhaust seats ground out and replaced with hardened ones anyways. I'm still going to have them magnafluxed as a confirmation of their integrity.

In the Tyclone thread that I hopefully linked to (Aaah fcuk it, here it is Tyclone vortec swap), the author mentioned that he didn't think that the enlarged exhaust/intake valves made tham much difference.

Having read about other people cracking vortecs (I know you're talking L35s here), is it really going to benefit you?

Just a thought..

:2cents:

The person doing the machine work suggested the 1.94/1.60 combination. He said that allowing the exhaust gases to exit a wider (1.60) opening would only help with the turbo Vs. a NA setup. He also mentioned that a 2.02 intake valve wouldn't increase HP by much (if at all).

-P