sunbeamtiger.co.uk

Over the past two years my Tiger has progressively used more oil. On the Schloss Dyck trip to Germany I had to top up twice. Also the oil pressure used to drop alarmingly when the oil level dropped, then was strong again on refill.

In October I took off the heads with the engine in place. This revealed worn valve guides but also showed some scoring in the cylinder bores.

So out came the crossmember, block and gearbox.

On strip down 5 of the eight pistons had broken top rings, worn con rod, big end and camshaft bearings. Surprisingly she didn't lay down a smokescreen just a puff on overrun and the performance wasn't that bad.

The engine is a 260 and has already been bored to .030. Cam fitted was a standard 289. Edelbrock performer 289 inlet manifold, tubular headers, Holley 600 carb and Mallory distributor. The oil pump was a high volume high capacity unit - fitted in 2009 by a previous owner. Sump was standard 5qt.

So what to do. Junk the motor and fit a 302 or rebuild the 260.

Costings worked out cheaper to go the 302 route. But there are so few 260 Tigers left that I decided against the sensible option and will rebuilt the "boat anchor". But with a few modifications.

It would be interesting to know how many 260 Tigers remain in the UK these days.

*** TO BE CONTINUED***

Lou.



A bit easier without the heads, but still a pain.



Broken rings.

Mine's a 260 which really could do with a refresh/refurb/rebuild so I'm watching.

Ours is 260 and runs well I have a gt40 302 brand new ready and waiting but as 260 runs so well I really don't wont to change it I almost drive it without respect for the fact its an old engine but it just does not use oil and pulls so well.

Whilst there is nothing wrong with a 260, once you tried your 302 you'll regret waiting so long. Keep the 260 as a spare when selling the car.
Then try a supercharger!!

Bob you're a bad influence I'm not going to even tell you what state the car is in at the moment.

The block and heads have been sent away to be machined, block has been honed to .040" and decked. Crank and heads are still to be worked on.

I'm fitting ARP bolts to the conrods and new pistons/rings/bearings. Will change the 289 cam for an Edelbrock Performer. Will have new pushrods/rockers (roller)/valve springs and valves. Heads will have valve stems and valve seats re-machined. I'm also going for screw in rocker studs.
Heads have been ported to the inlet manifold and headers. Bottom end will be fully balanced.

When I enquired about the oil pump I was told that a high capacity pump should not be used with a road going 260. The standard sump won't hold enough oil. A HC pump was fitted to the engine prior to strip-down!

Hi Lou,
I presume that you mean your block has been bored and then honed to .040 thou oversize not just honed.
Also when using a Performer camshaft in a 260,you should check piston/valve clearance as if you are using flat top pistons they may not have valve reliefs in them,and the camshaft lift may be critical,with machined heads and block.
You can run a Hi Volume oil pump with a stock oil pan,original BOSS 302 did.

I've got one, no problems, although there is a train of thought saying you don't need one and it also robs power to the wheels.

I'm just about to drop the engine out of mine to change a ring gear. Got any tips for dropping the engine without a crane? Did you use the two jack method and where's the balance point with box attached?

Hi Guys

The block had already been bored to .030", there was some wear to the bores so it was honed out the other .010" and thankfully has cleaned up. It's the valve guides I'm having machined incidentally not the valve stems.

I'll check about the clearance with the pistons as I am using flat toppers.

I just gave Real Steel a long list of parts after a lengthy discussion with them as to what in their opinion would work best on a 260.

Sump wise I'll try a Moroso 20503, it's 1.5" wider each side so with luck (or a big hammer) it will clear the suspension and give extra capacity with internal baffles.

I did use the two jack method, one to jack up the car one under the gearbox tailshaft with a wheeled dolly under the sump. I filled the boot with bags of cement and 5 gallon drums of water just in case. Bear in mind I didn't have heads on the engine. Maybe a though for a separate thread to see what others have tried?

Lou.

Don't trust honing; it will egg-shape and create more of a ring problem for you. All those broken rings indicate too much movement with clearance issues. The meaty 260 block can be bored .060 easily. I have made 289's out of them with no problem and even tossed in a 3.00" crank for torque.

Don't overload the boot too much. I had a surprise when using 2 jacks method, on undoing last engine mount bolt the front of the car shot up into the air [stopped when open bonnet hit garage roof] rather than the engine drop down! Had car up on 4 stands though for max access. Had engine/box in & out a lot in last few years using large trolley jack under sump & smaller jack under gearbox. Just make sure that engine is well supported on removing last bolt & try not to be under engine at the same time. I find it easier than engine crane.

Gearbox has now been fully rebuilt, painted and ready to bolt up to the engine.

The engine block and heads came back from machining and have been painted Ford blue. Most of the assembly work was has been completed but was delayed as the sump I bought needed modifying to clear the cross member. This has now been done and the final work should be done this weekend.

Aside from the block, heads, con-rods, and crank, everything else is new and in most cases performance upgraded.

I made the choice to stay with a 260, however the cost for machining and parts was almost as much as an off the shelf, assembled 302 RS crate motor, not cheap! Time will tell if I've made the right decision.



Gearbox rebuilt and painted, note Hurst shifter linkages.


.040 oversize block rebuilt with new pistons, rings, bearings & performer cam


Heads, ported, valve guides replaced, rocker studs threaded. Fitted with upgraded pushrods, springs, roller rockers, screw in rocker studs and new valves.


Unmodified Moroso 20503 sump alongside old unit.


Measured against a sump that fits and cut accordingly.


Plates being welded in, off to be replated.

Are you going to put a breather on the gearbox?

I wasn't intending to fit a breather. Is there a need? The box, although rebuilt wasn't in that bad a shape after 98,000 miles without one.

Hi Lou,

Do you mind telling us where you got the machining work done on your engine?