Need help with Ls1 valve info..

[gonridnu]

As a side note I don't know how accurate the info is but the only thing I can find on the VAM 282 says they utilized a 2.05 intake valve and a 1.675 exhaust. Granted it's a little different cylinder head but it's essentially the same per cylinder volume as our engines.

[Dezertxj88]

As a side note I don't know how accurate the info is but the only thing I can find on the VAM 282 says they utilized a 2.05 intake valve and a 1.675 exhaust. Granted it's a little different cylinder head but it's essentially the same per cylinder volume as our engines.

Man gonridnu its been a while since I've seen you on! Hows the motor been working?
With what you said, I would need a 1.675 exhaust valve to take full advantage of the 2.00 intake correct? I'm not looking for gains by going to the bigger valvesl..I was just looking for a cheap upgrade/replacement cause I bent 2 intake valves, which is why SBC & LS1 stuff poped to mind vs stainless aftermarket 4.0 stuff. Cost was the major factor! I was draw to LS1 stuff because of the tuliped shaped valves which will benefit me quite a bit, with a .038 quench lol and also because I found a great great deal.
I ended up on the LS1 stuff because I just bought 16 valves/springs/retainers & locks for 41 shipped to my door..I couldn't beat that anywhere!

I guess my new questions are, should I run the 1.55" exhaust valves, or should I keep my 1.50" which are perfectly fine? The intakes are 2.00" and exhaust are 1.55", just stock Ls1 valves. I'm not worried about more machine work to the head, I'm just a little worried about unshrouding the valves enough?
Obivouslly bigger valves leads to more shrouding and makes it harder to unshroud them..thats my main concern I guess.
I will be porting my Renix head slightly, and I know I'll probably loose a little flow at lower lifts cause the bigger valves, hoping the slight porting/clean up will counter act that so I don't loose any flow at lower lifts, but we will see..

Haven't completely decided on a cam yet, but it'll be the 87-95 single pattern or a comp 232.

[gonridnu]

The valve size increases are minimal with the exhaust being .025" bigger radius and the Intake being .055" larger from centerline. It's a pretty basic combustion chamber but if you polish it you're taking some small amount off you can roll it over a little where it departs from the cylinder wall.

And no I wasn't really recommending larger exhaust valves per se but I wouldn't discount the idea for a high RPM or turbo/nitrous/blower application. It was more of a statement that an increase in cubic inches can support larger valves while maintaining air velocity. Valve size is also dictated by intended use and RPM range so I could see an application where maintaining the stock sizes would be appropriate. I haven't really messed with heads that much but some standard rules apply. I simply increased my valve size relative to the displacement of the engine and did some massaging of the ports. Unfortunately I never got it on the flow bench so who knows but I'm very confident it flows a reasonable amount better than stock just based on sound principles.

The stock port volume and valve size on the 4.0 promote low end torque. They are comparable to those used in a 400 chevy small block which, with it's short rod length, was considered a purpose built torque version of the 350 that when used for performance applications came with a larger valve size per cylinder than our 4.0's do. Since valve and port size are a little on the small side there is not a lot of downside by opening up the bowl and valve face areas and cleaning the ports up to increase volume and promote smoother airflow.

[gonridnu]

And my junk is running fine. I just ordered a 97-01 10 blade electric A/C fan and am gonna put on a Napa 272310 fan clutch before summer to complete my cooling system upgrades (3 core copper brass radiator, Hesco water pump, Mac's radiator surge tank). I haven't had any problems cooling, but it gets hot out here.

[Dezertxj88]

Nice I'm also running the 10 curved blade fan. But I've got a tarus fan in mine. Deleted the mechaincal one, that is by far my most favorite bolt on! You could phyiscally feel the difference and see the rpms climb quicker with the mechaincal fan! It also cleaned up my mileage some...31's and 3.55's with a 5speed, I'm seeing 18-19mpg in town and around 22-23 highway..thats with around 300k on the clock, OG motor, but I suspect it have been rebuilt..its high mileage and doesn't burn oil or anything, no loud lifters..I have done every bolt on possible + some lol.
The tarus fan is set for 200* low and 215* high. The stock efan comes on around 208-210*..its worked so far, the tarus fan will come on around 195-200 and stays on for a brief period and shuts off..never had it high the high speed yet after 8 months. Last summer with the A/c on it still hasn't hit high..Guess I should test it in LA traffic!

But for a stock cam, what would I want for install height and for open/close pressure? Revving to 5250-5300rpm..just to keep this easier on me and the wallet, I've decide the stock 87-95 cam is what will remain in my jeep.
And kind of a forward statement, but what would it cost roughly to just have you do my head? I'm in cali, you Vegas, but I could ship all the stuff to you once I port it..I know you've gone through this before and I would feel alot more trusting/comfortable with someone whos has done the work before.
My machine shop doesn't seem stupid or unknowledgable, but they've also said this is the first jeep 4.0 they've worked on. Done Lsx and ford stuff though..just makes me a little nervous to have them doing my head.

[IH 392]

As a side note I don't know how accurate the info is but the only thing I can find on the VAM 282 says they utilized a 2.05 intake valve and a 1.675 exhaust.

The article "AMERICAN MOTORS FORGOTTEN SIX" in the October '69 "Rod & Custom the VAM 252 head uses the 343 V8 valves, 2.02 intake and 1.62 exhaust, don't know why they wouldn't use them in the bigger engine?

[gonridnu]

I didn't realize this was a Renix head. I don't really know shit about them. I'm pretty sure the additional machine work to put oversize valves in is more than the savings in parts and the stock valve sizes are going to be good for that port. Without the benefit of a performance cam and an increase in induction capability by means of the raised runner head and later style throttle body/manifolds it's more work than it's worth.

But for a stock cam, what would I want for install height and for open/close pressure? Revving to 5250-5300rpm..just to keep this easier on me and the wallet, I've decide the stock 87-95 cam is what will remain in my jeep.

I don't see in the FAQ what the stock cam lift is (i know it's around here somewhere) but I'd probably just shim the stock spring pressure up to about 90-110 on the seat and call it good on open pressure as long as you have room before coil bind.

My machine shop doesn't seem stupid or unknowledgable, but they've also said this is the first jeep 4.0 they've worked on. Done Lsx and ford stuff though..just makes me a little nervous to have them doing my head.

For basic machine work like this any competent shop with decent equipment should be fine. If they are still in business in this economy they probably know what they are doing, but it pays to check around ... ask some V8 racers and see who they use. For cylinder head work I like to make sure they have a floating head ball drive Serdi style seat and guide machine. It's harder to screw up when the machine does almost everything.

what would it cost roughly to just have you do my head? I'm in cali, you Vegas, but I could ship all the stuff to you once I port it..I know you've gone through this before and I would feel alot more trusting/comfortable with someone whos has done the work before.

Basic machine work for a ported HO cylinder head runs about $500 - $600 at the shop, I'd have to check their current prices (FYI...machine work out west is more than back east) . That would include surfacing, installing bronze guide liners, cutting for larger valves, bowl hog, installing hard seats, a bowl radiused 5 angle valve job, setting stem heights, and final assembly. Port work and parts are on top of that. I'd wanna get $350 to port a cast iron 6 cyl head and for .450" max lift and a guy would be looking at another $200ish in parts (springs, valves, locks, seals) so the total is about $1200 + core for a ported H.O. head with LS-1 valves and a spring suitable for .450" lift.

I have access to a Superflow porting bench and can flow a head for an additional fee, but can't imagine it's worth the expense for the average guy other than bragging rights. Optional spring and retainer set ups to suit high lift applications are available at an additional cost for parts and machine work as required.

[Dezertxj88]

Ya the shop I'm going through has done some pretty decent stuff, some Ls guys on Ls1tech actually recommended this shop because they've already dealt with them. I'll find out what they want to charge me.

[Dezertxj88]

Alright a few quotes in and I'm liking what I'm hearing. Highest I've had so far was 500 and change which to me isn't to bad since my bottom end will cost all of 800 bucks. So around around 1000-1200, pending how much work I do on it..I'll have a built 4.2L ready to take 8psi of boost by summer hopefully!
Now onto the more exciting news. I found another junkyard within 50miles of me..never knew it was there. they do "wheel barrel" days. $150 for the barrel, anything fits its your for 150, they said they've had guys stake 4 and 5 axles...rules are anything goes, only rule is - no lashing or tieing stuff down and while paying you can't touch/hold anything! If anything falls out before you pay for it, then it goes back to the yard..the kicker is, the junkyards on a hill..checkout stands at the top..I'd say 15-20% incline over 150-200ft..Nothing to bad.

So onto the junkyard saturday! Going to find me a HO to become a donor! My main concern about the swap is the fuel lines? Do I really need HO fuel lines? Or can I use my renix fuel rail & renix fuel lines?
I know what all needs to be done..I just never really got that part of the swap?? HELP!
I will be adpating my renix 60mm bored throttle body onto the HO intake. I have a spacer, so I'll just use that spacer as a adpater..I want to keep my jeep looking stock under the hood.....minus the turbo:)

[Dezertxj88]

Double post lol.


On another note, I found out my thorttle bodies a 61mm..I've got to be one of the only ones with a renix throttle body above 60mm..most say 58.5-59mm is the biggest you can go.
http://www.jeepstrokers.com/forum/viewt ... p?f=5&t=62
I bought this from maubdib last year! Extremely happy with it, and I will be using the throttle body spacer as a adpater to run my renix stuff on a HO manifold! Easier, no TPS hassle, and maybe people will think its still a renix

Anywho questions. My only concern is the fuel lines! I don't understand why they need to be swaped? I will be getting a 91-94 motor, using my renix fuel rail on the HO manifold, so why would I need HO fuel lines? Can someone help me here?
Not worried about anything else except for the fuel lines, the next hardest thing will be the adapter but I can magane that! Advice/explain the fuel lines though please?

[Dezertxj88]

And so far most shops are saying you CANNOT ream 8mm guides to 11/32?

[IH 392]

And so far most shops are saying you CANNOT ream 8mm guides to 11/32?

You'd need a special reamer with the .312" pilot and .343" flutes.

I haven't fallowed along with this thread very well?, but the LS1 valves I have are 8mm stems? so I don't know why you'd ream them out for old skool SB valves?

[Dezertxj88]

And so far most shops are saying you CANNOT ream 8mm guides to 11/32?

You'd need a special reamer with the .312" pilot and .343" flutes.

I haven't fallowed along with this thread very well?, but the LS1 valves I have are 8mm stems? so I don't know why you'd ream them out for old skool SB valves?

Edit:
Ok just redid some searching and found out I had written down SBC valve stem diameter of 0.341" since I was originally going to run SBC stuff, Ls1 stuff is indeed 0.315".
Thank you 6time, again you set me straight Got me using the Ls1 stuff and just saved me from making a fatal mistake lol.
So no more $118 + new guides..haha awsome! Less cost at the machine shop.

[jeep7081]

Why not use the dodge ones?

In- P5249877 Stainless swirl polished 1.97 $16 ea
Ex- P5249876 Stainless swirl polished 1.625 $14.50 ea

[SilverXJ]

Their price. Use Magnum valves, not larger, but swirl and stainless. But not from Mopar. try SI valve.