Generation IV Internal Engine - Just got my L92 heads in

Very impressed with the level of consistancy and quality in both the machine work and casting. The intake valve job is much nicer and has more potential than any of the other LSX heads thus far, same for the exhaust. It has a nice 4 angle instead of the generic 2 angle. Each valve guide is incrusted in less material and more cleanly done. I dont know how much CFM really will be gained by removal of the base material. Not as much as a 241/243 for sure. Bore width of the chamber looks to be right at 4.040/4.045. So you guys with as little as 4.020 bore should be fine. Need to check some tolerances and thicknesses, but expect some ported numbers within a couple of weeks.

Brandon

Who are you having doing the port work on the heads? And what combo are you throwing these on?

Nate

I removed the sig info because of non sponsor issues, but I am a head porter. They are going on a 422 based iron block.

Brandon

I'm really glad these are finally out. Give's us budget guys a really nice set of heads for the price.

I removed the sig info because of non sponsor issues, but I am a head porter. They are going on a 422 based iron block.

Brandon

looks like they are nice heads. they are $175 bare each from SDPC. they SDPC said will begin doing an intake manifold for the L92 heads for non-truck cars.

would the L92 heads fit on LS2 block with stock valves with out valve interference with the block. what is the minimum bore size for the L92 heads to fit?

what is the valve's angle degree of the L92 heads? how about the pistons to valves interference with the stock valves? what is the maximum valve lift and duration before i enter the piston to valve clearance issue?

thanks.

looks like they are nice heads. they are $175 bare each from SDPC. they SDPC said will begin doing an intake manifold for the L92 heads for non-truck cars.

would the L92 heads fit on LS2 block with stock valves with out valve interference with the block. what is the minimum bore size for the L92 heads to fit?

what is the valve's angle degree of the L92 heads? how about the pistons to valves interference with the stock valves? what is the maximum valve lift and duration before i enter the piston to valve clearance issue?

thanks.
4.000" i believe

4.000" i believe

I'm stealing your sig. Sorry.

looks like they are nice heads. they are $175 bare each from SDPC. they SDPC said will begin doing an intake manifold for the L92 heads for non-truck cars.

would the L92 heads fit on LS2 block with stock valves with out valve interference with the block. what is the minimum bore size for the L92 heads to fit?

what is the valve's angle degree of the L92 heads? how about the pistons to valves interference with the stock valves? what is the maximum valve lift and duration before i enter the piston to valve clearance issue?

thanks.

Based on the chamber width and the size of the intake valve (2.16), I wouldnt run these in anything smaller than a 4.020, really 4.040+ is what would be best. Its still the stock 15* angle I am pretty sure. Someone needs to confirm that though. As far as PTVC goes, you are going to lose around .030 over a 2.00" if everything else is straight up and the valve angle is 15*.

Brandon

What intake are you running?

What intake are you running?

Sheetmetal with 105mm accufab. Going to start on it next week. After that I scraped the idea of using a divided plenum (4) TB setup and am going to design one like the harrop.

Brandon

did you actually measure the valves? if not would it be possible to measure them with something accurate like calipers?

Thanks a bunch.

Didnt get the valves in yet, I just order 2 intake and 2 exhaust. The gm sets are like $95 for the intake and $115 for the exhaust. However, I did measure the valve seat surface and the width I have is 2.145 intake and 1.585 exhaust. So for sure they are 2.16/1.60.

Brandon

xfactor
what kind of flowbench will u be flowing the heads on?
how does the short turn look?

xfactor
what kind of flowbench will u be flowing the heads on?
how does the short turn look?

SF600, no tricks, no bullshit.
The short turn looks like this.

http://www.picturehosting.org/images/xfactorpitbulls/l92int2.jpg
http://www.picturehosting.org/images/xfactorpitbulls/l92int.jpg

Man, those didnt turn out very well. I will get some better ones later when I get out in the shop with better light. Its just too damn hot right now. To answer your question, the turn is more laid back by probably 10* and doesnt have a drastic transition angle right before the seat like the LS6. It is also more balanced, meaning not lower on one side or the other. Looks sharp. Between the last few non LSX castings I have dealt with (All Pro, Dart, and the L92). I like it the best. So many characteristics of a real race inspired head.

Brandon

What is your opinion on the exhaust port shape and size. A local head porter told me today that he would not touch the shape or opening size even though the flow #'s that have been reported are a little low.
He said it is one of the best exhaust ports he has ever seen in a production or out of the box aftermarket head. He really likes the short turn too.

What is your opinion on the exhaust port shape and size. A local head porter told me today that he would not touch the shape or opening size even though the flow #'s that have been reported are a little low.
He said it is one of the best exhaust ports he has ever seen in a production or out of the box aftermarket head. He really likes the short turn too.

Its the nicer than the LSX stuff. But it is undersized from the opening into the bowl. The opening is 1.56" or so, and could stand to grow to around 1.62" and carry that width in just past the guide (for 1 3/4" header, 1.72" for 1 7/8") The bowl itself could bell out more past the guide and curve more back into the seat. The shorturn is about like the LS6, there are a few things you can do just to it to squeeze out about 10 more cfm. Great head, but has alot more in it. I just dont like the fact that the valve cover bolts have a boss in the runner. Looks as if we could have another hole in the runner aside from the rocker arm boss. Also have the check the thickness for the spring base pocket. It doesnt give much either, and obviously busting through to it will ruin the head.

Brandon

I just put my set on my LS2 block (4.005" bore), I only have an exhaust valve in it but it has .038" clearance from the side of the cylinder wall.
The intake valve will probably be a little closer.

Well since the L76 is a 4.00 bore with L92 heads I'ld say the LS2 4.00 should be able to take the L92 head.

The question that should be asked is this.
Both the L92 and L76 have dish'd pistons and the LS2 has flat tops so will you need L76 pistons in the LS2 to keep from having a Piston to Valve issue. Or does the L76 have dish'd due to the Cam phaser???

can you tell me if the exhaust ports are in the same location as ls1 heads??? I would hate to have to rebuild my turbo headers to make a set of these heads fit.

http://www.ls1tech.com/forums/attachment.php?attachmentid=67302&stc=1
http://www.ls1tech.com/forums/attachment.php?attachmentid=67303&stc=1

Here is a cut of the intake port.

Robin

I'm stealing your sig. Sorry.
its no prob man:)

on another note, cant wait to see results=)