Jump to content
HybridZ

A Ls1 headed ford based 240sx


Crazy eyes

Recommended Posts

Ok well my project has started,it is quite a weird one. The car is a '89 Nissan 240sx,the bottom end is a 351w. The plans are 351w block, 400m crank,Forged rods(4.00" throw)Forged .030 over pistons to complete the bottom end. Now the heads are going to be Ls1 heads, Yes Ls1 heads. They fit on sbf blocks with a little work on the headbolt holes. The reason I am going for this instead of some after sbf aluminum heads is because I picked these up from a buddy of mine who went to aftermarket heads on his ls1 and sold me these for 75.00 dollars.The cam is going to have to be a custom grind because the valves on the ls1 heads are reversed from a Ford.We are making a custom sheet metal intake with individual runners to a single plenum. To help it breath I am going to use a stock Lightning TB which I am getting for free from a buddy who just upgraded to a BBK but the stock ones flow over 1000cfm. As far as the wiring goes I think I am going to run a early 302 speed density computer and harness and run a tweecer piggyback program for tuning issues. I will post some pictures as soon as the motor is in car.

Link to comment
Share on other sites

Well I know that the Ls1's have 10.1:1 compression,but I am not sure how much it will have,As far as everything lining up it is dead on.The rockers are dead aswell as the water passages are spot on,It came when we bought the ls1 heads,and my friend has a 302 apart and we put the HG to the bottom of the head and EVERYTHING lines up,I just called Camotion and they said for a custom grind cam it's going to run 700.00.

Link to comment
Share on other sites

I really would like to know how much modification that's really gonna require, and how similar in shape the water passages are.

 

Might actually be a very interesting swap to look into as used LS1 heads can be much easier to come by than good aftermarket heads for a SBF.

 

What are you gonna run for an intake and exhaust?

Link to comment
Share on other sites

What LS1 head casting were you planning on using? Would it be possible for you to post pictures of your ford short block with an LS1 head gasket on it so we can all see how coolant passages, and head bolt holes would line up? Thanks in advance. I was also wondering if you know the dish volume of your pistons.

Link to comment
Share on other sites

Sorry for not posting any pictures,my cable internet has been down so I am stuck with 56k for awhile.Also the headgasket that we were using was a .030 over HG.As for the headbolts they line up perfect but on the intake side the holes need to be grinded to make a little bigger.And yes the pushrod and lifters are dead on aswell. The only thing is where the 302 has oil passages,the ls1 heads are going to just dump the oil into the valley,but there are plenty of holes for the oil to drain back into the block.

Link to comment
Share on other sites

Thats amazing, surprised no one thought of this sooner. It is good for people with old Fox's who can't afford an LS complete, but the custom grind is a pain I bet.

 

It's been done before on mustangforums.com

 

And you STOLE those heads for 75 dollars. While I commend you for what you're trying to do, seriously, just sell the heads for a wad of cash and put it towards some SBF heads. Unless ofcourse you're going for that "Are you serious?" factor.

Link to comment
Share on other sites

Sorry for not posting any pictures,my cable internet has been down so I am stuck with 56k for awhile.Also the headgasket that we were using was a .030 over HG.As for the headbolts they line up perfect but on the intake side the holes need to be grinded to make a little bigger.And yes the pushrod and lifters are dead on as well. The only thing is where the 302 has oil passages,the ls1 heads are going to just dump the oil into the valley,but there are plenty of holes for the oil to drain back into the block.

 

Here's a guy that posted pictures of this head swap. This is real hot rodding and thinking "outside the box".

 

http://460ford.com/viewtopic.php?p=138256

 

g

Link to comment
Share on other sites

You know, some of the cam details still make me wonder...

 

...would it be ideal to run a LS1 type profile cam designed to fit a SBF block, or run a SBF type profile came in a reverse lobe in order to fit the LS head?

 

But it looks like this custom cam won't be cheap, but not a deal breaker. If you really do score the heads for less than $100, and you fab your own intake or use spaces to fit a junkyard intake you might be able to do the whole thing for less than $1k, which is still cheaper than most aftermarket heads, and this combo should flow pretty well.

 

Guess we'll have to wait and see, but it'd sure be wicked to see 350+na hp out of this combo.

 

In the previously linked thread they talked about the pistons needing to have valve reliefs grinded into them. I'd kinda like to know what the CC difference of the heads are and how much clearence would need to be made to accomdate a high lift cam. Though I might be on my own for finding out.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...