Inliners International Forums General Discussion Engines 292 build advice for a 4X4.

Gentlemen,
I am a first time poster who is just learning about US engines for my new project. This machine is a 1967 Land Rover NADA spec long wheel base station wagon. Think of your classic African safari film and you’ve got it.

This old bus originally came with a Rover 2.6L 6 cyl engine that is known for being a bit of a dog so one of the previous owners replaced it with a Chevy 292. I am rebuilding the truck to recover it from years of abuse and am looking at what I want to do with the engine while everything is apart. The 292 looks like a fun engine with potential and it actually fits very nicely into the LR engine bay which makes it much more attractive than the mods required for a V-thing.

Some basic specs of the vehicle are:
Weight : 3752 lbs.
Gearbox: Ford NP435 with granny low gear and 1:1 top. This will be mated to a .87:1 overdrive transfer case, 3.54 diffs and 32” diameter tyres. If anything I will change to 4.1:1 diffs but that is considerably more expensive for this truck.
Aerodynamics: Brick like to non existent.

Now I am looking to get about 200hp (Anything above that is fine too!) out of the 292 and wish to consult on the best ways of getting there. I’m looking to be able to have reasonable freeway performance but am also looking to optimize fuel consumption as I don’t need her to be a drag racer. I’m used to the old LR engines which tend to the agricultural rather than performance so a lot of this tuning is a new concept to me.

I already have a Clifford intake and Langdon exhaust manifolds as a start. From lurking and reading I think I want to:

1. Bump the compression to 9:1. Is the best approach here to shave the head, use a 194 head or use the propane pistons? Is it necessary to zero deck for this level of build?
2. Keep the bottom end stock other than the possible piston swap.
3. Retain the stock cam.
4. HEI for sparks.
5. I think the exhaust will be 2 2 ¼ downpipes y’ed into a single 2 ½ pipe all the way to the back of the truck with a single silencer.
6. I think I want to go the TBI route for fueling. This is mainly because I haven’t done it before and it would be fun to try. Any benefits to economy or power will be good. So far I have found kits from Howel, Affordable Fuel Injection and of course, there is the Megasquirt option. I’m also following Efi-diy’s TBI installation thread.
7. Now comes the fun part. I may be able to spring for a lump port head. The big question would be that given my cam choice is it worth it? From the descriptions it does provide a huge increase in volumetric efficiency which, if combined with the right gearing, can only help fuel economy. In addition, what would be the best valve size for this engine set up? Am I going overboard here?

All comments are appreciated as I realize that I am new to these Chevy engines. Any comments on what kind of fuel economy to expect would be useful as well although I know the weight, drive train losses and aerodynamics work against me here.

Cheers
Gregor

Personaly I do not think you need to zero deck the block.And 9-1
compression can be easy to get. Even just off the CCs of the head. But Zeroing the block can also help. Or like you said the
LP pistons can help. But bottom line is,You need to know what the CCs are of the piston , piston to deck & the CCs of the head.
Also you have to take into account is also the head gasket being
used. So as you can see The compression can be gained from
anyone of these area's. Lets say you stay with the Stock Block(decking)stock pistons,stock gasket thickness. You can just mill
to gain your wanted compession. Most 230,250,292 heads range from 72.76CCs -- 74CCs. So it just maybe a matter of knowing what head is already on the motor and Going with a different CC
head. Now as to a Lump ported head The air flow is improved right
from the start .100 lift. And it works with any Valve size even
the stock valve. But you can step up to a 1.84 or a 1.94 intake
an 1.6 on the exhaust.
my personal 2cents is go with the 1.8 & 1.6 for a good daily
driver if your still trying to get ALL that you can in the MPGs
or stay with the stock size valve. Even with a stock 1.72 vlave
and the Lump port & porting your still looking at least a 15% gain in the CFMs, Over a stock valved head & no porting.

Twisted has most of it right for a 250 or is 2 bit kinda guy. 8-]

Let me add zero decking the 292 is a bit of a problem. When I torn down my 292 for rebuild I had .072 from piston to deck. In Leo Santucci's book he doesn't recommend more than .030 off the deck.

The LP pistons IIRC will get you 9.0:1, but as Twisted says you need to check your CCs.

Larry

Your most likely after bottom end grunt, so I suggest keeping the cam small, the stock one is a bit too small though. Something about 195 deg @ 0.050 will help wake the motor up without killing bottom end.

Certainly tbi will help if your doing any rock climbing - no float issues to dael with. I'd go with dual 2" exhaust pipes rather than 2 1/4 mainly to get the exhaust velocity up at low rev's.

well i dont zero any of my 250s.I don't touch of them UNLESS they need it.For me by not zero decking them I have more valve to piston clearance. My main reason is I run pop-up pistons.
And most are not custom orders. But they just a pop-up for a
307. and are milled for my valve clearances.I know i could zero the decks for more squash in the quench area But i don't.
Now as for your is 2 bit kinda guy. 8-]comment
not sure i follow that 1. But anyway i forgot about the recommendaton more than .030 off the deck on the 292s.

No offense intend, just referring to the mean 250s you run.

Larry

You should be able to improve economy and low end torque by going with an aftermarket camshaft.

Usually a cam listed as "improved economy" and "improved torque" will be efi friendly whether speed density or mass air, so that wont be an issue.

A good hdy cam with a lift between 500-550 and a Lobe seperation
of 112-114 will give you nice lowend to mid range power and give
you good Vacum for power brakes.along with a nice idle.

I personally zero deck all my engines.
It has less tendancy to detonate when they are zero deck.

All the LS1's & LS2's have a positive deck,(pistons come out of the block)

That is part of the reason they can run high compression on pump gas.

MBHD

hank, you are correct that a zero decked motor is optimum. but on a 292 with a stock type piston, the block would need so much cut off the deck it would be scary.

if i could recomend cams. go to the comp cams website. look at the inline cams. there are 3 in the high energy catagory. pick either the 1st or 2nd one. keep the lift less than .500 and duration less than 210 @ .050 .
i guess the 3rd one would good also. all are bigger than stock. keep in mind the part #'s are for a 250. for a 292 change the prefex # of 61 to a 62.

HYDRAULIC-Good performance upgrade for Hyd. Hyd. 500 to 4500 61-113-4 240H 240 248 192 200 .455 .455 108°
stock camshaft. Excellent torque and mileage.
Very smooth idle.

HYDRAULIC-Good city and highway Hyd. Hyd. 800 to 4800 61-232-4 252H 252 252 206 206 .474 .474 110°
driving, strong vacuum.Works with
stock computer. Good torque and mileage.

HYDRAULIC-Best for towing, off-road Hyd. Hyd. 1000 to 5000 61-233-4 260H 260 260 212 212 .489 .489 110°
and 4WD trucks. Noticeable idle.
Good for highway driving.

big lift cams wear valvetrain out too fast for a street engine. ie: valves, guides, rockers, springs.
tom

one thing you guys seem to keep over looking,
his ride is close 4000lbs and he would like to
see at least 200hp.(which will be pretty easy to get but he would like to see more & not be a racer )
I think anyone of these cams would work nice
The first to me is kinda on the small side for that much weight.
1) 245/262 lobe 112 Gross lift 468/505 Dur@.050 199/207 rpm band
idle-4500
2) 262/272 Lobe 112 Gross lift 505/530 Dur@.050 207/217 rpm band
Idle-5000
3) 272/272 Lobe 112 Gross lift 530/530 Dur@.050 217/217 rpm band
Idle-5500
Pesonaly I think these would be better with a lump ported head
and will still give Good Idle as well as Vacum ,And still work well with the EFI.
again just my 2cent

Gentlemen,

Thank you for your input.

From your comments I gather the following:

I first need to strip the head from the engine. With this done I need to measure the deck clearance to the top of the piston and the cylinder bore diameter. As I am going for a fairly mild build I don’t expect to have to use anything other than the stock Felpro head gasket. With this information I should then determine the head volume and buy accordingly. If I choose to LPG pistons can I buy them as .030 over or do I need to go to a .060 overbore? The engine has been rebuilt at least once so I presume it has been bored already.
I am still undecided about zero decking. It sounds like it is not such a good idea on a 292. As I am only going for 9:1 CR and sticking to a fairly mild cam I would not expect to run into detonation problems.
A lump port head is a good thing. If I’m spending that kind of money I should go for the 1.84 I and 1.6 E valves. With these valve sizes and one of cams described above is it necessary to use bigger valve springs? In this day and age of unleaded fuel should I just get hardened valve seats installed now? Bear in mind this will be a supplied head and not a rebuild of my current one so I wouldn’t expect valve recession.
Thanks for the CAM info. I was hunting on line yesterday and couldn’t find much for 292s other than Clifford. Larry, where are the cams you describe for sale?
Exhaust. Efi-diy, I take it you mean 2” downpipes? Unfortunately this truck has a serious box frame chassis that doesn’t lend itself to routing a full dual system. I don’t want to lose ground clearance. What would be the preferred set up for a single outlet system?
Efi-diy, do you sell fully assembled Megasquirt boxes for the inline 6? I’ve started attempting to digest the info on their website but that is a lot to get your head around. I have no problem with harnesses but I tend to come from the ‘If you can’t fix it with a hammer it must be an electrical problem’ end of the spectrum so building boards myself is out. I looked at the Affordable Fuel Injection kit but I think I prefer the idea of being able to tune it myself.


Thanks for the input. I bought Leo’s book and read it and found lots of useful information. My only problem is that it fells like it is geared to the rodder or drag engine builder while I am looking at a warmed up truck engine. I’m trying to refine that information for my needs.



Hopefully I’ve included a picture of another truck showing the final product I am shooting for in my build.







Of course, mine looks like this right now. A long way off and a lot of time and money to spend!







Thanks

Gregor

67NADA Landy/Gregor

I can get you any cam grind you want.And no you shouldn't need
Big springs. I most cases Lifts under 550 The Z28 V8 springs will work.
If you want to Email I'll be more then happy to help you out anyway I can.

Let me start with zero decking. To zero deck the 292 you need a set of custom piston $500-600. I'd go with Federal Mogul LPG pistons they will get you close to 9.0:1 and shaving the head will make up the difference. The stock pistons are 8.6:1 and the dish on the LPG piston is about half the stock piston. Let the machine shop tell you what you will need for oversize pistons. IIRC the LPG pistons are Hypereutectic and have a different expansion factor. Also zero decking will get you closer to 10.0:1 with the stock head.

On the Felpro gasket set get one with the 85001PT1 head gasket it is a step above the standard. It has additional sealing around the vent, and push rod holes.

If anyone knows the l6 head Twisted6 does, what ever he says goes.

Before you put the motor together you will need to know the deck clearance, combustion chamber CCs, stroke 4.76, bore size, and the CCs of the dish in the piston to calculate compression.

Larry

Thanks guys.

Larry I'll PM you this incoming week. I'll need to pull the engine and inspect it before going much further. It's supposed to be 112° here in Phoenix tomorrow so it will most likely be a week or two yet before I get to do it.


Cheers
Gregor

Any up dates we need more pics.

Updates it is then.
The truck itself is making slow but steady progress. She is 40 years old and spent a lot of that time on a ranch so everything is getting stripped, cleaned, overhauled and painted but is also being kept within a monthly budget. As of this week I have:
· Dismantled her down to the chassis, repaired the rear cross member and added new strengthened mounts.
· Wire wheeled the entire chassis down to bare metal, cut off the old engine mounts and unnecessary brackets, welded in a notch to one cross member for prop shaft clearance, repaired some slight rot on the frame horns and welded in some strengthening to mount a Saginaw PAS box from a Scout II. I then went through the full skiddle with POR15 to complete it.
· I rebuilt the front and rear axles to use 3.54 Range Rover diffs. This is temporary until I get a feel for the engine and gearing after which I expect to rebuild these into Rover/Toyota hybrid axles with front disc brakes.
· I repaired the cracks in the bulkhead and welded in new foot wells which were originally rotten.
· I took the original radiator panel and fabbed up a new duct and mounting for a big Howe aluminium cross flow radiator. This and the bulkhead are going to be galvanized this month.
· I took the old steering column and fabbed up a new mounting and support bearing to support a revised inner column that will now turn the PAS using Borgeson joints and collapsible shaft.
· I also sourced some doorposts but they are up in Wyoming. Does anyone know how to ship oversize parts cheaply? 55lbs 6’x4’x1’

I also have a set of very fine rock sliders, a front bumper and a gearbox adapter kit being made at Pangolin 4X4 who are Rover specialists in Oregon. The drivetrain is going to be a 292 mated up to a Ford NP435 with granny low 1st mated to the series Land Rover high ratio transfer case (.87 hi/2.35 Lo) which should be pretty bomb proof. This gearing should give me about a 3.08 ratio in top pushing along on 32” tyres which puts me at about 2400rpm at 65mph.

As for the important info for this forum concerning the engine the simple overhaul I was thinking of turned into a build. The spec is:
· Chevy 292 block acid dipped and bored .060. It also seems to have been decked at some time as the .040 pistons that were in there only measured .005 down the hole. This is at the machine shop.
· Stock crank with journals cleaned up. This is at the machine shop.
· Stock rods mounted with LPG pistons to bump the compression. I expect somewhere in the region of 9.5:1 or so. The rotating assembly is getting balanced. Summit has been dragging their heels getting these to me.
· A lump port from Tom Lowe featuring 1.8I and 1.6E valves. A fine piece of art it is too although, much against my wife’s better judgement, it is currently decorating our living room.
· She’ll breathe through a Clifford water heated intake and Langdon cast exhaust manifolds. I am currently trying to figure out how to do full duals to the back of the truck but off road clearance is more important to me than sound so we will see. I also know that an Offy intake would be better for low end torque but the Clifford is what I’ve got so we’ll see how she runs.
· 3 groove harmonic balancer that is being overhauled by Damper Doctors.
· 153 tooth flywheel.
· Comp cams 260H cam. This is actually a 250 part as they now tell me that all 292 cams are special grinds coming in at $300 as opposed to about $150 for the 250 item. I am using a ‘lecky fuel pump so I didn’t spend the extra money.
· Comp cams lifters, standard rockers, push rods and timing gears.
· Fueling will be by a 2 barrel TBI run using a Microsquirt. Can anyone comment if the Holley 670 (502-6S) would be beneficial here over a stock GM 5.7L TBI?
· Oh and a Felpro 1025 head gasket.

As a nod to the hot rodders I am looking for an Aluminium rocker cover but that is pure decoration. Anyone care to guess at a final HP and Tq rating?

I have about another 9 months to a year to go to get her on the road. Here’s a couple of piccies. The truck as she stands right now and also a shot of the engine and LR gearbox as they came out.

Cheers
Gregor

From what I read above it doesn't sound like you have the pistons from Summit yet. I just looked at Summit and was surprised to see they have so many offerings for the 292. I didn't know anyone had a Hypereutectic, LPG piston as mentioned above and I see that Summit doesn't list one either.
At this point I hope you already know the LPG has .150" deep dish and the original low c.r. dish is .310" deep. They show the cast LPG with various 980P numbers and the deep dish hypereutec as 909P numbers.

Engine's done. After a couple of months of building and fabbing brackets for everything I have finally got her to a point that I am ready to drop in.

Here's the piccies.






It was a fun engine to build.

That is looking great. What a good plan for a 4X4. That transfer case is huge! If my '70 Blazer's 350 ever gives up it'll get a 292 or 4200.

Nice Job, Looks good , Just a heads up I had my alternator down low like that and it gets really hot that close to the header,[ Just crawing on the trail ] I moved my up between the power steering pump and head. Good luck keep us posted