griffman
Active Member
- Posts
- 474
- Location
- horley surrey
Well boys they have done it again
my bezzie, who is also my brief, has advised me to stipulate that I am talking bout the old lot based at Aldershot who went tits-up a long time ago and not the Sloane family who currently own the brand - and who I also consider to be my friends (Hello Dave and Alex!!!)
I digress.
Just when I thought I had a handle on what this mob got up to between 1990 and 2003 when they stopped doing the chevy engines I find myself flummoxed once again.
Here are the variants of L98 350 small block I have seen on various disco's classics,P38s and defenders - not to mention a Rover P5B Coupe they built for Laura Ashley's son - the strange rover!
305 (5.0) carb
350 (5.7) carb
305 TBI - throttle body injection
350 TBI - throttle body injection
350 TBI - with alloy heads
350 TPI - tuned port injection
350 TPI - with alloy heads
350 TPI - with alloy heads and large throttle body
all of above had dizzy.
All of the above had either manual or ZF 4-speed HP22 Vacuum gearboxes
350 TPI - with alloy heads, large throttle body,coil packs and OMEX ECU
383 TPI - with alloy heads, large throttle body,coil packs and OMEX ECU
These were in the P38 570HSE and 630R vehicles with HP24 Electronic boxes - hence the OMEX which can talk to the HP24EH gearbox ECU.
So this bit makes sense at least.
The only common feature of all of them was at least they used the same basic post-86 L98 block, usually a 4-bolt with single piece RMS - (some 305ci cars had 2-bolt caps - but that is ok on those).
Now I find myself with another 'whatever was around at the time' special - as had been the case with my own car(don't ask)
It is in a 1995 soft-dash LSE that was converted at a cost of 45000 pounds in 1997 - every option - including the £8000 satnav/sony PS etc etc.
it is in my care because, after 165000 miles since being put in - the chevy block threw a rod at 6000 rpm when the previous owner was showing off.
So the new owner buys the car - it also needs some cosmetics and re-trim, but is very solid as had been kept in a garage and has a meticulous service history.
The car is badged as a 570HSi - so we pop the bonnet expecting a TPI 350, alloy heads, standard GM TPI ECU and a dizzy - as it should be with a Vacuum gearbox.
I looked at the engine and found the alloy heads as expected - BUT - it also has coil packs, so I am thinking it must be early OMEX car with gearbox module disabled or has had a GEMS ecu adapted to suit - Mark Adams had once told me he had done this for them a few times
Nope - neither of those - so we have a new version - little black/silver box the size of a GEMS ECU with NO IDENTIFYING FEATURES WHATSOEVER.
It is not the marine-type either - I am flummoxed
Anyone able to point me in the right direction?
The other issue - replacement engine.
The new owner has been in my 383 stroker defender and wants to upgrade to that size - as we will be buying a complete new bottom end anyway it is only a few hundred quid more to get the stroker kit.
He does not have unlimited funds so we decide to go with a L98 4-bolt 383 from GM Performance and then balance it all nicely and overhaul and refit the top end - the TPI is reliable and relatively economical when set up right and we have a very good machine guy who does great work on refurbing old heads.
To do this I need to make sure the combustion chambers are not too small to cope - want to keep the CR under 10 for driveability and reliability.
Guess what - there are no casting numbers or ID marks of any kind on the heads - all we can tell is they are slightly larger valves than standard and have angled plugs - so they could be anywhere from 58CC corvette type
to 70CC or above.
Very frustrating.
Even if we use LC pistons there is a risk of too-high CR if the ports are the tiny ones.
So we have to get them checked before we do any work
Does anyone have a nice pair of 64cc-plus ali heads that would be suitable?
Any help or info greatly appreciated fellas
Griffman
my bezzie, who is also my brief, has advised me to stipulate that I am talking bout the old lot based at Aldershot who went tits-up a long time ago and not the Sloane family who currently own the brand - and who I also consider to be my friends (Hello Dave and Alex!!!)
I digress.
Just when I thought I had a handle on what this mob got up to between 1990 and 2003 when they stopped doing the chevy engines I find myself flummoxed once again.
Here are the variants of L98 350 small block I have seen on various disco's classics,P38s and defenders - not to mention a Rover P5B Coupe they built for Laura Ashley's son - the strange rover!
305 (5.0) carb
350 (5.7) carb
305 TBI - throttle body injection
350 TBI - throttle body injection
350 TBI - with alloy heads
350 TPI - tuned port injection
350 TPI - with alloy heads
350 TPI - with alloy heads and large throttle body
all of above had dizzy.
All of the above had either manual or ZF 4-speed HP22 Vacuum gearboxes
350 TPI - with alloy heads, large throttle body,coil packs and OMEX ECU
383 TPI - with alloy heads, large throttle body,coil packs and OMEX ECU
These were in the P38 570HSE and 630R vehicles with HP24 Electronic boxes - hence the OMEX which can talk to the HP24EH gearbox ECU.
So this bit makes sense at least.
The only common feature of all of them was at least they used the same basic post-86 L98 block, usually a 4-bolt with single piece RMS - (some 305ci cars had 2-bolt caps - but that is ok on those).
Now I find myself with another 'whatever was around at the time' special - as had been the case with my own car(don't ask
)It is in a 1995 soft-dash LSE that was converted at a cost of 45000 pounds in 1997 - every option - including the £8000 satnav/sony PS etc etc.
it is in my care because, after 165000 miles since being put in - the chevy block threw a rod at 6000 rpm when the previous owner was showing off.
So the new owner buys the car - it also needs some cosmetics and re-trim, but is very solid as had been kept in a garage and has a meticulous service history.
The car is badged as a 570HSi - so we pop the bonnet expecting a TPI 350, alloy heads, standard GM TPI ECU and a dizzy - as it should be with a Vacuum gearbox.
I looked at the engine and found the alloy heads as expected - BUT - it also has coil packs, so I am thinking it must be early OMEX car with gearbox module disabled or has had a GEMS ecu adapted to suit - Mark Adams had once told me he had done this for them a few times
Nope - neither of those - so we have a new version - little black/silver box the size of a GEMS ECU with NO IDENTIFYING FEATURES WHATSOEVER.
It is not the marine-type either - I am flummoxed
Anyone able to point me in the right direction?
The other issue - replacement engine.
The new owner has been in my 383 stroker defender and wants to upgrade to that size - as we will be buying a complete new bottom end anyway it is only a few hundred quid more to get the stroker kit.
He does not have unlimited funds so we decide to go with a L98 4-bolt 383 from GM Performance and then balance it all nicely and overhaul and refit the top end - the TPI is reliable and relatively economical when set up right and we have a very good machine guy who does great work on refurbing old heads.
To do this I need to make sure the combustion chambers are not too small to cope - want to keep the CR under 10 for driveability and reliability.
Guess what - there are no casting numbers or ID marks of any kind on the heads - all we can tell is they are slightly larger valves than standard and have angled plugs - so they could be anywhere from 58CC corvette type
to 70CC or above.
Very frustrating.
Even if we use LC pistons there is a risk of too-high CR if the ports are the tiny ones.
So we have to get them checked before we do any work
Does anyone have a nice pair of 64cc-plus ali heads that would be suitable?
Any help or info greatly appreciated fellas
Griffman
Last edited:
