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Hey all, I'm relatively new here and planning on upgrading an LO5 in a 1990 G30 van - stock is '190 HP, 300 lb-ft' and is currently connected to a TH400 trans, and ends at a 14 bolt with 4.10 gears, 32" tall tires...
I'm looking to build some lower RPM torque, and I'll take the horsepower that come with it, but it's not my main concern...
the only upgrades I've made so far are a set of 1-5/8" full length headers and dual 2.5" pipes, thrush welded mufflers, converter delete, electric fan upgrade, and K&N filter with open housing...
Not currently installed, waiting on spring, I picked up an extra TBI, to which I did the 'ultimate TBI mods' and made the fuel pressure regulator adjustable; made a carburetor-to-TBI adapter out of 1/2" aluminum, open TBI spacer out of 5/8" plastic; Weiand stealth intake manifold with the center divider cut out; new stock vortec 350 roller cam (191I/195E duration, .414/.428 lift, 110 LSA)...
there's a set of 14014416 HO 305 heads that I'm looking at picking up - they're marine use, and they have stainless valves, and I plan to port them a bit (first time); plan to pick up some 1.6 ratio rocker arms - and the usual gaskets, timing set, etc with rebuilding stuff...
I'm not dead set on using the cam, I would sell it for a GMPP roller, but if it comes down to it, I will run it...
does anyone have advice about this combination, using specific parts...?
I would try to find a hotter cam. Even a stock 049 TPI cam that has 207 213 duration would be much better. LT1 roller cam at 202 207 duration and around 465 lift would also be a good choice. These are cheap cams you can usually find around $60-80.
To be totally honest, I've been lurking the forums for a long time reading and researching, and joined due to Fast355's responses...!
I'll have to message him, thanks...
I read these forums on days I am bored at work.
Saw your 4L60E soon comment....Don't waste your time, they will not hold up in a van with any kind of power. My stock 350 Vortec took out two of them in my Express van. The stock in 38K and the built up 4L65E in 40K (@ 78K). Stick with the TH400 or swap in a 4L80E.
As for your cam question, it is easy to overcam the thing with the stock torque converter. I would probably run the F/Y-car LT1 cam or a similar aftermarket cam. The Comp 4x4 206/210 @ .050 cam I had in my Express van was fun up to about 5,000 rpm.
I have done the 305 heads on the 350 TBI before also in my G20. Ran very strong off the line but gave up at about 5,000 rpm. Part of that was also the cam selection. I had a Mellings MTC1 in that engine. The 416 heads will lack some of the holes you need to mount your accessory brackets and do not have enough meat to physically drill and tap for them. I would look for 081s or 083s if you want to stay with the factory accessory brackets.
However that being said you honestly have the best GM heads ever created for torque. All you have to do is run the right cam for them and will have plenty of torque. I am a little unorthodox when it comes to camming the swirl port heads. I run single pattern cams or very close splits. None of this 8-10* split you see with most aftermarket cams. If you plan on tuning at all a cam like the Elgin E1136 works very well in the powerband a stock TBI head works well in.
regarding the 4L60-e, I already have it... I helped a good friend of mine cut up some parts vans, and got the trans, crossmember, full wiring harness, computer, and some other odds & ends for helping out - it's out of a '95 G20 and it's been rebuilt... I'd like the OD for highway driving - basically my whole push toward building a lower RPM torque engine... something that can scoot a little from a stop-light, on ramps, sometimes do burnouts... but mostly to do better on driving a few hundred miles to other van shows...
I do have the option of changing rear-ends - because I also own a '95 G30 Beauville with a 3.23 rear axle ratio (7400GVW - also has a '60-e) so we'll see what happens...
Thanks for that link to the cam - something to think about... there is a guy on my loca Craigslist with a stock TPI 305 roller cam, I could go look at that... I would really like to retrofit a roller, I have all the parts off of a junkyard Vortec 350 and I'd be really pissed to wipe a lobe...
I havent pulled a valve cover yet, but I'm assuming the 350 heads are the 193 castings... They smoke a little, so either way they'd need to be rebuilt, but I was hoping to rebuild some heads and do a weekend swap of the cam, intake, heads...
regarding the 4L60-e, I already have it... I helped a good friend of mine cut up some parts vans, and got the trans, crossmember, full wiring harness, computer, and some other odds & ends for helping out - it's out of a '95 G20 and it's been rebuilt... I'd like the OD for highway driving - basically my whole push toward building a lower RPM torque engine... something that can scoot a little from a stop-light, on ramps, sometimes do burnouts... but mostly to do better on driving a few hundred miles to other van shows...
I do have the option of changing rear-ends - because I also own a '95 G30 Beauville with a 3.23 rear axle ratio (7400GVW - also has a '60-e) so we'll see what happens...
Thanks for that link to the cam - something to think about... there is a guy on my loca Craigslist with a stock TPI 305 roller cam, I could go look at that... I would really like to retrofit a roller, I have all the parts off of a junkyard Vortec 350 and I'd be really pissed to wipe a lobe...
I havent pulled a valve cover yet, but I'm assuming the 350 heads are the 193 castings... They smoke a little, so either way they'd need to be rebuilt, but I was hoping to rebuild some heads and do a weekend swap of the cam, intake, heads...
Most of the TPI 305 engines have the tiny garbage L03 TBI cam in them. It is pathetic with only like 179/194 duration. The 180 hp version of the TBI Caprice 350s used them.
The TH400 van I have in my posession had 3.08s in the back.
The cam I linked to is a factory style roller cam. 210/215 @ .050, .462/.470 lift on a 110 lsa. I actually have a bigger cam than that in my 305 Vortec in my Tahoe and it pushes the Tahoe down the road just fine at 1,650 rpm @ 70 mph.
Ok, I'll have to see if there's a number on the end of the cam he can send me...
So these heads, and a larger cam should be good to go...
That Elgin is a bit above the 14097395 Chevy Performance roller cam that I have really been eying up...
Also, I've really been looking at 1.6 rockers - would I really need them going to a larger cam...? Figured for sure with the stock Vortec cam they'd be a necessity...
electric fan upgrade, and K&N filter with open housing...
I wouldn't call either of those "upgrades".
Originally Posted by truckin_wny
Not currently installed... ...Weiand stealth intake manifold with the center divider cut out
Cut OUT, or somewhat reduced in height?
If the divider is GONE, the manifold is toast until you weld or epoxy something back in to prevent fuel slosh from upper to lower plenum.
Folks used to cut a slot in the dividers, about 1" by 1" or less. Allowed some communication between the two planes. The divider was more-extensively cut out of the aluminum BBC dual planes used on L-88s, but that was not really an engine intended for "Low-RPM" use.
Carving the divider out of a low-rpm manifold seems counterproductive.
I wouldn't call either of those "upgrades".
[LEFT]
Having owned the same Van, BOTH of these are upgrades in terms of power and performance. The factory air cleaner and ducting is tiny and becomes restrictive. The 454s had a much larger system than the 4.3/305/350s did and is a nice upgrade but difficult to find.
If you use an OEM quality dual fan setup with a factory style shroud, have OE quality wiring and relays, and have the proper control in place, the electric fans are a HUGE upgrade over the mechanical clutch fan in power and efficiency. However I will say in the case of my Express van, a pair of Tahoe electric fans on a 34" wide big block radiator could not keep the 350 cooler than 240-260*F on a hot 105*F day, dragging my 6,000 lbs travel trailer uphill running the a/c where a massive duramax clutch fan kept it running 180*F. So unless you are running the engine at or near wide open throttle, at higher rpm, dragging something heavy uphill in high heat the electrics work great. I ran a 170*F thermostat with a 185*F low fan turn on and 190*F high fan turn on. In the winter time they practically never ran (only stopped in bumper to bumper traffic for 5-10 minutes) and when they did it was low speed only, drawing about 10 amps for 30 seconds at a time.
Ok, I'll have to see if there's a number on the end of the cam he can send me...
So these heads, and a larger cam should be good to go...
That Elgin is a bit above the 14097395 Chevy Performance roller cam that I have really been eying up...
Also, I've really been looking at 1.6 rockers - would I really need them going to a larger cam...? Figured for sure with the stock Vortec cam they'd be a necessity...
I ran that cam with 1.7:1 roller rockers in my 350 Express with 2.02/1.60 valve 906 vortec heads, a L31 marine MPFI manifold, and thorley tri-y headers. The heads had been surfaced about .010" and I used .016" embossed steel shim head gaskets to get the quench down around .042" which bumped the compression from 9.4 to 9.6:1. I could not run much timing (28-29* total and only 24* until 4,400) in the setup even on 93 octane. When I switched to burn E85 I was able to advance the timing to be at 34* by 2,600 rpm and gain as much as 30 ft/lbs of torque at the tires and 20 hp. I put down 272 RWHP @ 4,700 and 325 RWTQ @ 2,900. I pulled that cam and switched to a GM 357 HP SPO 350 cam and dropped back to a 1.6:1 roller rocker. If it lost any torque at all it was under 2,000 rpm far under my converters stall speed. The converter that had been stalling 2,700, stalled 2,800 with the hotter cam. From 2,800-6,200 the SPO cam was a rocket compared to the 395' cam. Although I will say after years of abuse I did hurt the rod bearings due to high rpm oil starvation.
Ok I sold the stock Vortec cam today, so I’ll be picking up that Elgin in the next couple of weeks...
I milled down about 3/4” of the Weiand Stealth intake manifold - I’ll be running 2 open spacers/adapters, should have enough open area under the TBI...
I’ve tried loading pictures on here in my first few posts but it wasn’t posting for some reason - trying with this post, too...
My old clutch fan was sticking, and the electric fans were off of an ‘03 Caravan that we’re going onto my wrecked one, but I didn’t end up fixing it - so the fans, wiring, and installation were ‘free’ to me... I’m also running a 140 amp alternator from a Buick Roadmaster, and a 1.5” serpentine belt pulley...
Should be tearing the engine down in about a month, just about done gathering parts, going to do some bowl work on the heads, New seals, all new gaskets for the engine...
So I picked up a pair of 10422601 heads off of a marine block, low run hours and they’re very clean...
cleaning up the castings a bit, but I’m not totally sure if I’ll run these or try to flip them to find another set of 193’s to rebuild...
would the higher compression work with the 210/215 duration...? I’m still planning to get 1.6 rockers either way, and if I have to run a slightly thicker head gasket to keep compression in check...
Hoping to get the engine running this week/next weekend...
I rebuilt the 305 heads and am using them, and have the Elgin 1136P cam in it now - all of the roller conversion is done, New double roller chain, gaskets, port matched the intake and heads, and got some 1.6 roller tip rocker arms...
once it’s running around and stuff I’ll start doing the data logging to work on the computer...
Hoping to get the engine running this week/next weekend...
I rebuilt the 305 heads and am using them, and have the Elgin 1136P cam in it now - all of the roller conversion is done, New double roller chain, gaskets, port matched the intake and heads, and got some 1.6 roller tip rocker arms...
once it’s running around and stuff I’ll start doing the data logging to work on the computer...
Roller tip is fairly pointless, full roller has better benifits. I would stick with 1.5s because there is not much to be gained in the 0.500 lift range on stock 601 castings.
got the cam and chain all set today, timing cover on with new seals, hoping to get the oil pan done tomorrow, and maybe move onto the intake after that...
02-12-2018, 05:25 PM
