Engine and Transmission Tech

Jim, If I understand, only cast iron head available? Norstar head can't be swapped-on? 4.9L has likely more bore potential than Northstar? Used a forged crank yet? Northstars too expensive? Thanks, roverman.

Maybe you could chop off the flange part of the intake and graft on a different one like this:

[www.buickperformancegroup.com]

Not that you'd happen across one with ports like that. Just a thought.

Until "someone" bothers to feed us exact bore spacing, head swap don't look good. The shortblock might be a good way to go, if we can get rid of the"dorky" stuff.

Sometime next week I will have one in my possesion to measure everything.The guy that made that manifold in the link above is very talented! I was thinking that on the early single plane manifold you could cut off the top and weld a flat aluminum flange like these Trans-Am 351 Cleveland Holley manifolds. Then you could do Dual Quad ,Tri-power, Webers or even a Blower manifold just by bolting a different top on.




Edited 2 time(s). Last edit at 01/05/2010 10:53PM by mgb260.

I like if we can find a "user friendly" head for it. May want to consider Melling sleeve# CSL 308 F(flanged,3.9"bore x1/16" wall).roverman.

I keep finding references that put the bore spacing at 4". I'm looking forward to when you get your spare block. Put some mystery aside. Wouldn't it be great if it was more like 4.4"?

I haven't seen anything on the 4.9. The Northstar is 4".If you look at the comparison pictures the Northstar bores are touching(3.66" bore). The 4.9 looks to have a lot of space(3.62" bore).It wouldn't surprise me if it wasn't the same as SBC at 4.4".Or it could be 4.24" like the 215/Rover, it is hard to tell by looking at pictures.I've seen pictures somewhere of LS heads sitting on a SBF and SBF heads sitting on a LS block (same 4.4" bore spacing).Here is a couple more pics of the 4.9.







Edited 3 time(s). Last edit at 01/08/2010 02:39PM by mgb260.

LS 4.8/5.3 looks pretty close (3.78" bore),4.4" bore spacing. Would'nt it be great to bolt on LS heads! Here are pics of an LS block without sleeves compared to a 4.9 block.Also an older 327 chev pic.






Edited 3 time(s). Last edit at 01/08/2010 02:31PM by mgb260.

My intake idea would be similar to the Edelbrock GM V6 base. Just bolt the top you want on. The biggest problem with the Caddy is lack of aftermarket support. So you have to improvise. If it becomes more popular like in the Fiero and Kit cars, that might improve.The small port size might hurt on a large stroker also. Maybe I will get an extra head to section and see how much we can improve that without hitting a water jacket.I am making a home made flow bench using a shop vac and MAF sensor (voltage to flow calculations). The chamber looks just like the Vortech Chevy heart shape.The port size looks small like the early small block Ford. It looks like with 4" bore you have room for 2.02/1.60 Chevy valves.Of course you would have to unshroud the valves. Because of the smaller ports 3.8" bore might be more realistic, but I guess you can't beat cubic inches.




Edited 1 time(s). Last edit at 01/11/2010 08:40PM by mgb260.

Next Monday I get my 4.9 and rear wheel drive intake(front water outlet) and oil pan(rear sump). The 94 was sold, so I had them get me a 92 from Portland. I will have to find valve covers yet.Evidentaly 82-85 4.1 are steel(chrome on Eldorado).86-89 4.5 TBI finned aluminum.



Edited 3 time(s). Last edit at 01/12/2010 09:16PM by mgb260.

I looked at the Melling sleeve catalog and there are specs for the Cadillac 4.1 sleeves(Cadillac just bored them out for 4.5/4.9): Flange dia. 4.213, length 5.580. LS 1 flange dia.4.320, length 5.600(.020 longer).Correction:4.5 is bored out from 4.1 sleeve but 4.9 is shorter because they increased the crank counterweight diameter when they stroked it. 4.9 sleeve is 5.395 long. Caddy must have 4.4" bore spacing. 4.213" outside dia. and still has space between cylinders.Those LS1(3.870 bore) sleeves might work if there is enough meat in the block for a interference fit. The step on the bottom would have to be bored down .020" deeper. That would be a straight sleeve, no O-ring or step. By the end of next week i will find out . The wrecking yard called and said my engine was in, but I have 2 more 12 hour shifts and can't pick it up until Tuesday.



Edited 5 time(s). Last edit at 01/27/2010 02:22AM by mgb260.

Uhhh... Jim ? When I do the math it comes to only .020" deeper ? Is not the LS1 sleeve designed to be dry ?(metal around it ?) Good Luck, Art.

Typo Roverman,fixed, thanks .Yes the LS1 sleeve is meant to be dry, but is thicker than the stock sleeve. I was thinking, the bottom part interference fit with about 2" of block filler above that. I also read that the LS 4.8/5.3 (3.78 " bore) is thicker and can be bored out to the LS1 size.Probably same outside diameter.You might be better off using that for 3.8" bore. I just thought the factory liners would be a lot less expensive than aftermarket.



Edited 2 time(s). Last edit at 01/17/2010 07:32PM by mgb260.

You could always chew the top off 20 thou. How thick do the sleeves need to be to be wet?

I don't know, but thicker without the metal around them, would be more ridgid. Probably stay round better when the heads are torqued also. I thought if I have to bore it out anyway I would just go .020 deeper.



Edited 1 time(s). Last edit at 01/17/2010 11:37AM by mgb260.

Clan, "Dry sleeve in a wet world", many would contend arrox..12" min. wall, but this is somewhat comparing a flyswatter to nuclear fusion. That Melling, HP. sleeve is approx 30-40% stronger than standard and reflected in price at approx. $111. ea. Lots of variables to consider here, effective compression, boost, type/coolant temp, area of sleeve un-supprted,lateral thrust, pre-ignition/detonation(a real deal breaker). I think, Nic' has a better way and time will tell. roverman.

I got my engine home. I'm too tired from 5 hours driving and we are having a heck of a windstorm. The early manifold has really small runners and looks like the old Tarantula manifold. The later one on the engine looks like the Performer dual plane with much larger ports. The oil pan is still one large sump like the later one. I think the 4.1 manifold and pan are off a 85 tranverse FWD. So the manifold still has the rear water outlet.I'll have to look at 82-84 to see if they are different.The engine was complete except no distibutor,starter,alternator or throttle body. The 4.1 intake has a TBI throttle body on it.Tomorrow I'll hang it from the cherrypicker and pressure wash it. Pictures and measurements of bore centers soon.



Edited 1 time(s). Last edit at 01/19/2010 09:55PM by mgb260.

Jim. Thanks for up-date. What if huh ?? "She took the Kaeddy-didn wanna let me ride"-John Belushi, long may he cruise.

Sweet! Can't wait, Jim. Should be fun.

Hey Jim,I'm really exited about your project,I'm sure you will have ideals about things that I had never thought of.I'm sure,like me,the project is more about eccentricity and uniqueness and not really about horsepower and "going fast",obvious,because we all know,how eaiser and cheaper than can be achieved.Projects like this are allways so damn much fun!!!

I hope you are realizing how mismatched the ports of RWD intake manifold are for 4.9 head.Of coarse,It can probably be gasket matched,however that manifold is a serious detune for the 4.9,all the porting anyone could ever do,would not make it flow anywhere close to the 4.9 manifold.That was the same problem I had with the 4.5 tbi unit,when I thought,I wanted to carb my engine,and the 4.1 RWD unit was alot worse than the 4.5.I'm sure,you must have something else(modification) planned for the RWD manifold.

I'm looking forward to watching your progress!

Thanks...
Chad