1098 vs 1275

[Wes]

This must be an old topic but cant find anything specific by searching.

My Traveller is not a daily driver (<1000 miles/yr), will hardly ever go near a dual carriage way let alone a motorway, and is just for weekend fun. The engine is the original and although its done less than 100,000 miles i'm sure its very tired. So my mind is turning to a new engine (I'll keep the original as its matching numbers). My "how long is a pirce of string" question is would i expect to see/feel some more "pep" with a new 1098 engine or should i take the plunge and go for a 1275 with all the issues that may arise?

What are your thoughts?

PS would by be wise to replace the gearbox too?

[svenedin]

Yes you will feel a difference between a "tired" 1098cc and a rebuilt one. I had my 1098 rebuilt (it is the matching numbers original engine).

In order to fully benefit from a rebuilt engine all of the ancillaries need to be in good order as well of course: carburettor, distributor, fuel pump etc.

How much extra pep you get depends on how tired the old engine is. A compression test would be useful.

Personally, I don't see the need for a 1275 for a car that is little used. I have a 1098, and like many others, happily take the car abroad on long trips.

Stephen

[myoldjalopy]

One option is to have the original engine re-built. As you car is 'just for weekend fun', I agree with Stephen's comments - and your mention of "a 1275 with all the issues that may arise" is indeed something to ponder over carefully. If the gearbox is good, I would leave it alone.

[simmitc]

I commuted on country roads and dual carriageways, and holidayed (long distances including motorways) with standard 1098 engines, covering 18,000 miles per annum. Yes, there were times when I wished that I had a bit more power, particularly when towing a trailer up a long hill; but the 1098 coped perfectly well 98% of the time. I have driven 1275 cars, but for weekend use <1K miles per annum, I would stick with a standard 1098 unit - no modifications required, everything matches the manuals, simple and reliable.

[Mervin]

I tend to agree with the others.
Personally I don't see the point of the extra work and expense in fitting and converting to a 1275cc engine for a car only used occasionally for "fun". Would that larger capacity engine be too much for the 1098cc gearbox? Would a different clutch be required?
I suggest sticking with the engine you know and have that rebuilt.

[Wes]

Thank all.

I think you've just reinforced what i had as a gut feeling.

Next question would be where to get current engine reconditioned? any suggestions in the south of England?

[svenedin]

It's definitely worth mentioning that your engine may seem lacking in pep for lots of different reasons that are not due to the engine being worn out.

Before committing to an expensive rebuild do a compression test. If the compressions are good proceed with a full service to include a thorough tune up (check valve clearances, ignition timing, points gap, condition of distributor, cap and HT leads, fuel mixture, spark plug condition and gap, oil, oil filter, air filter etc). You might find you can improve performance to the point that the engine does not need a rebuild at the present time.

Stephen

[Bill_qaz]

Also is your current engine:
Smoking
Knocking or rattling
Hard to start
Using excessive oil or water
High blow by, oil filler cap removed can crankcase pressure be felt blowing out.
As Stephen advised do a compression check.
Also borescope are cheap to buy, usually linked to your phone screen, take plugs out and turn until piston at bottom and look at bores. Look for heavy scores, wear lip at top. Many come with mirror attachment which will help look up at valves.

Worth further checks before committing to a rebuild or replacement

[Wes]

It's definitely worth mentioning that your engine may seem lacking in pep for lots of different reasons that are not due to the engine being worn out.

Before committing to an expensive rebuild do a compression test. If the compressions are good proceed with a full service to include a thorough tune up (check valve clearances, ignition timing, points gap, condition of distributor, cap and HT leads, fuel mixture, spark plug condition and gap, oil, oil filter, air filter etc). You might find you can improve performance to the point that the engine does not need a rebuild at the present time.

Stephen

Good call. I will do this. Thank you. PO installed electronic ignition not that long ago plus has records of all extensive regular fluids/filter changes.

[Wes]

Also is your current engine:
Smoking
Knocking or rattling
Hard to start
Using excessive oil or water
High blow by, oil filler cap removed can crankcase pressure be felt blowing out.
As Stephen advised do a compression check.
Also borescope are cheap to buy, usually linked to your phone screen, take plugs out and turn until piston at bottom and look at bores. Look for heavy scores, wear lip at top. Many come with mirror attachment which will help look up at valves.

Worth further checks before committing to a rebuild or replacement

Engine not smoking, rattling in so much as a lot of tappet noise despite tappet clearances checked. No water usage, oil usage just the typical drips out the bottom!
God call re endoscope, i think Lidl do them occasionally.

All good point to think about. Thanks

[Bill_qaz]

Could have wear on rocker tips, so feeler gauge is bridging. Can you get access to spqr type tool, see posts on it.
https://board.mmoc.org.uk/viewtopic.php ... qr#p711258
Excessive valve clearance means opening late and closing early and can cause a power loss.
Maybe worth removing the rocker gear and checking for wear.

20250830_120229.jpg (2 MiB) Viewed 44219 times

[Wes]

Could have wear on rocker tips, so feeler gauge is bridging. Can you get access to spqr type tool, see posts on it.
https://board.mmoc.org.uk/viewtopic.php ... qr#p711258
Excessive valve clearance means opening late and closing early and can cause a power loss.
Maybe worth removing the rocker gear and checking for wear.
20250830_120229.jpg

Worth a look.

Thats a fancy set of rockers?

[Bill_qaz]

Could have wear on rocker tips, so feeler gauge is bridging. Can you get access to spqr type tool, see posts on it.
https://board.mmoc.org.uk/viewtopic.php ... qr#p711258
Excessive valve clearance means opening late and closing early and can cause a power loss.
Maybe worth removing the rocker gear and checking for wear.
20250830_120229.jpg

Worth a look.

Thats a fancy set of rockers?

They are just standard rockers on my 1098.
In the post linked I think there was a discussion about sintered rocker, with good explanation from Phil.

[Wes]

Forgot to ask, whats the expected Compression rating? 8.5:1?

[svenedin]

Compression testers either read in PSI or BAR or both. If the tester you are using only reads in BAR you can convert to PSI by multiplying by 14.5

What is important is not just the reading but whether all the cylinders have a consistent, similar reading. For instance if all of the cylinders read nearly the same but one is much lower then there is a problem (maybe a leaking valve or broken piston rings).

130-160 PSI is acceptable. This is assuming an HC (high compression) engine. These have engine numbers in the format 10MAUH or 10MEUH (the H denotes high compression, L denotes low compression)

Before testing compression, remove all of the spark plugs. This enables the engine to spin over faster on the starter. Label the HT leads so that you know where to put them back. For safety, disconnect the lead to the contact in the cap of the fuel pump. Then no fuel is delivered whilst the engine is being cranked.

Test each cylinder and write down the reading. Then add about 1 teaspoon of oil through the spark plug hole and test that cylinder again and repeat for the other cylinders. You will have 2 sets of readings: dry test and wet test. If the dry test readings are low but significantly higher with the wet test then the piston rings and/ or bores are worn. If a reading stays low the problem is with a valve.

Stephen

[geoberni]

Engine not smoking, rattling in so much as a lot of tappet noise despite tappet clearances checked. No water usage, oil usage just the typical drips out the bottom!
God call re endoscope, i think Lidl do them occasionally.

All good point to think about. Thanks

Can I just clarify something here, Endoscopes are for medical use, being inserted into body cavities. They are much thinner and more flexible than Boroscopes.
Boroscopes are for industrial use, being more robust and having brighter lighting since they aren't going to burn someone internally....

You can get boroscope cameras from the internet that simply plug into your phone or a laptop for £5-£10.
Of course, on ebay, they will be described as USB Endoscope Borescope Snake Inspection Camera 3 in 1 or similar catch all phrase.

[svenedin]

Engine not smoking, rattling in so much as a lot of tappet noise despite tappet clearances checked. No water usage, oil usage just the typical drips out the bottom!
God call re endoscope, i think Lidl do them occasionally.

All good point to think about. Thanks

Can I just clarify something here, Endoscopes are for medical use, being inserted into body cavities. They are much thinner and more flexible than Boroscopes.
Boroscopes are for industrial use, being more robust and having brighter lighting since they aren't going to burn someone internally....

You can get boroscope cameras from the internet that simply plug into your phone or a laptop for £5-£10.
Of course, on ebay, they will be described as USB Endoscope Borescope Snake Inspection Camera 3 in 1 or similar catch all phrase.

I wouldn't recommend a DIY endoscopy especially with equipment purchased from Lidl or eBay........


Stephen

[Bill_qaz]

Engine not smoking, rattling in so much as a lot of tappet noise despite tappet clearances checked. No water usage, oil usage just the typical drips out the bottom!
God call re endoscope, i think Lidl do them occasionally.

All good point to think about. Thanks

Can I just clarify something here, Endoscopes are for medical use, being inserted into body cavities. They are much thinner and more flexible than Boroscopes.
Boroscopes are for industrial use, being more robust and having brighter lighting since they aren't going to burn someone internally....

You can get boroscope cameras from the internet that simply plug into your phone or a laptop for £5-£10.
Of course, on ebay, they will be described as USB Endoscope Borescope Snake Inspection Camera 3 in 1 or similar catch all phrase.

I did say borescope Berni, cheap, linked to your phone. Comes with mirror to look in different direction.
Were as endoscope are often a pain in the butt as many of us of a certain age probably know

[les]

This is an Endoscope, needs a source of power for illumination.

IMG_1126.jpeg (2.46 MiB) Viewed 43810 times

[Wes]

Compression testers either read in PSI or BAR or both. If the tester you are using only reads in BAR you can convert to PSI by multiplying by 14.5

What is important is not just the reading but whether all the cylinders have a consistent, similar reading. For instance if all of the cylinders read nearly the same but one is much lower then there is a problem (maybe a leaking valve or broken piston rings).

Stephen

Excellent info thank you.