4G52 Mods???

[Andrew77]

Hi,

Doing my home work on a potential new engine for my GD Galant Rally Car. I am required by CAMS PRC (Production Rally Car) regs to run a engine variant fitted to my model at production. information I've found says the biggest engine fitted was the 4G52 Aston in the Japanese models. Therefore I must use this engine.

My Question is can you fit the 2.6L 4G54 internals into a 4G52, therefore taking it from 2.0l to 2.6l? Also seen a 2.6 taken out to around 3.0l does that mean that potentially you could take a 2l to around 3l or am I being extremely optimistic!!!

Are the blocks the same just machined differently to fit different internals?

Has any body done this?

If this is not possible what capacity can the 4G52 be maxed out to?

I understand that the 4G54 2.6l heads can be fitted to the 4G52, which series would be best considering that its going to get a lot of head work done and be coupled up to a set of twin 45 DCOE Webers?

Do not know much about the internals of these engines only have previous experience with Saturn engines.

Any info would be appreciated

[simon]

Hi,
I think I read on the this site that the 4g52 have cavities in the block which limit how far it can be bored and the 4g54 is a solid block[ I could be wrong]
In the early 80s Ian Hill [Gosford dyno tune] had a 4g52 non balance cam in his lancer, it was a 2.3. I think the pistons were Mitsubishi high compression kits from japan[I don't remember if they came with rods or not]
simon

[Andrew77]

Thanks for the info Simon, If 2.3l is the limit than that's still pretty good, currently car is fitted with 4g32 and which can be maxed out to about 1850cc, which is probably fine for the earlier and smaller GA -GB Galants, and LA/LB Lancers but with bigger body of GC-GD series probably not going to be enough. As the rules allow for me to run the Astron 2l with freedoms on the internals might as well go as big as I can.

Looking to have Powerplay in Moorabbin (VIC) build the engine. They have come highly recommended and do amazing work!

[A112H]

Would be a terrible shame if someone "confused" a 2.6lt block with w 2.0lt block when rebuilding.
Sometimes when facing the block you might accidentally clean the engine number off. Of course this would need to be re stamped, in this confusion you might mistakenly stamp a 2.0lt number on it.

What are your restrictions on intake?

[cheaterparts]

Hi,

Doing my home work on a potential new engine for my GD Galant Rally Car. I am required by CAMS PRC (Production Rally Car) regs to run a engine variant fitted to my model at production. information I've found says the biggest engine fitted was the 4G52 Aston in the Japanese models. Therefore I must use this engine.

My Question is can you fit the 2.6L 4G54 internals into a 4G52, therefore taking it from 2.0l to 2.6l? Also seen a 2.6 taken out to around 3.0l does that mean that potentially you could take a 2l to around 3l or am I being extremely optimistic!!!

Are the blocks the same just machined differently to fit different internals?

Has any body done this?

If this is not possible what capacity can the 4G52 be maxed out to?

the 4G54 2.6l heads can be fitted to the 4G52, which series would be best considering that its going to get a lot of head work done and be coupled up to a set of twin 45 DCOE Webers?

Do not know much about the internals of these engines only have previous experience with Saturn engines.

Any info would be appreciated

I had a quick read through the PFC regs just to see what they said before posting
first you wont bore a 4g52 to a 2.6 --- thats a 7 mm difference and there wont be any bore left
as metioned there was a 2.384 (4G53 ) vertion but it was and eng with a 98 mm stroke same as the 4G54 with an 88mm bore

you have to stay with the astron 1 head both the 4G52/54 astron 1 heads are the same and realy the biggest down fall if you wont to make the engine bigger
staying with the 2 lt will give you a wider spead of power with this head even ported

I built a 2 lt when I first ran my sigma at hillclimb it had a modest 84 Kw atw but had a good spread of power over a wide range
I also didn't know a lot about the astron back then

some off the spec at the time - the head was ported with most of the work to improve the inner radis on the inlet port and lifting the port a bit doing so - the guides were knocked out and most of the lump around the guide was taken out and bleaded before the guides went back in I tapered the section that was inside the port
I still used std valves but the seats were cut to the outside edge and the valve were back cut

I used a 35/75 cam with Crow double valve springs

I decked the block and sat the pistons prowd of the block by a couple of mm then machined a taper on the outside of the piston to deck height
then by fitting the head on a mill put the same taper in the head giving a tight squish band around the outside edge
the comp ran at 10.5:1

twin 45 mm DCOE13 webers with 37 mm chokes ( sorry cant remember what jetting I had )

the bottom end stayed stock apart from a little weight off the flywheel and the balance shafts removed

Knowing what I do now days I would pull more weight out of the moving parts - the crank with a bit of knife edging and fit a crank scaper
a lighter custom steel flywheel - a tilton race cluch ( or something that doen't explode - I had a presure plate explode so dont like cast things spinning at high speed any more )

I hope some of that could be helpfull even if its only food for thought

[Andrew77]

Thanks for all the info Guys,

Thinking that it might be just easier to build 4G54 2.6l and run the car under the Club Rally Car Rules which allows greater freedoms, stating engine must be from same manufacturer and have same number of pistons as original engine with from there basically anything goes with the exception of forced induction.

Can buy a lot of off the shelf performance bits so this should help to keep the costs down.

Plans for induction are twin 45 DCOE webers, therefore which head is best for this application.

[A112H]

Depends which way you go Andrew.
With the first catagory you will need to stay with a series 1 head. All series 1 heads are the same, 2.0 or 2.6 makes no difference.
If you go 4G54 you should be looking at a M7 head for the best stock flow but if you are allowed to massage the heads at all it really is up to you and budget. MR2600 is making awesome billet heads now that, from all accounts, flow brilliantly. They are designed for turbo set ups but would be equally amazing with a well sorted N/A

[simon]

Hi,
If you go club rally car rules you could use a 4g63 bored to 87mm, high comp pistons,dohc, hot cams[on another site they are talking about using 298,302 cams in n/a motors], ITBs from a blacktop Toyota 4age[45mm]
Simon

[cheaterparts]

Can buy a lot of off the shelf performance bits so this should help to keep the costs down.

Plans for induction are twin 45 DCOE webers, therefore which head is best for this application.

just wondering what you engine are you rallying with atm

both a 52 or 54 would do the job it just depends on what class you wont to run in

if you search posts for a guy called -- Panda --- he ( peter )used to run a 2.6 sigma quite well in rallys over in the Mt Gambia area
he hasn't posted for a few years
but from memory that car ran a basic M6 head with std Magna roller cam and hyd lifters -- it did run a magns EFI manifold and an after market computor
at one stage I beleve he had 14 rallys on the car without a DNF and the car went quite well

you dont have to go over board to build a good rally engine from ether astron

[A112H]

Off topic but Panda (Peter) made my coil over struts

[davetrees]

Would be a terrible shame if someone "confused" a 2.6lt block with w 2.0lt block when rebuilding.
Sometimes when facing the block you might accidentally clean the engine number off. Of course this would need to be re stamped, in this confusion you might mistakenly stamp a 2.0lt number on it.

... and that would be cheating, and the person would quite rightly be taken out the back an flogged ! There are other classes available if one wanted to run a 2.6 .....

you dont have to go over board to build a good rally engine from ether astron

Exactly ... and capacity (or even horsepower) isn't everything in rallying, as you know. ALWAYS spend money on suspension & brakes before power.

Build a good reliable 4G52 or 4G54 with moderate power & good torque .... then spend the money you save on the engine build on better suspension. http://www.mcasuspension.com is as good as you can get in this country .... don't let anyone try to tell you otherwise.

Mike & Simon at Powerplay do great work. Not cheap, but quality work never is.

[Andrew77]

Hi Cheater / All

Currently running 4g32, balanced and blueprinted to 1600cc. Twin 40mm DCOE, Ported head, o/s valves, Stage 5 Works replica cam, Tuned length 4 into 1 headers, but stock pistons. Comp ration only about 9.5:1. Its been a really reliable unit and has given me little to no trouble. As my driving developed I've found that I'm really driving it at the engines limit. I'm cornering at speeds comparable to most in similar classes/period cars just running out of straight line HP.

Most of my previous R & D has been improving, braking and handling and have got that sorted really well, see my thread Build thread for more info http://www.sigma-galant.com/viewtopic.php?f=48&t=10243

The car handles and stops really well. Got some really strong results running Rallysprints with this package when I was living up North. Having said that I am currently working on a brake upgrade to potentially match a more powerful engine. Starion ventilated rotors all round with Starion/Series 3 RX-7 rear calipers with Series 3 RX-7 4 pot calipers up front.

I know Panda (Peter) quite well, I will be seeing him in couple weeks when he comes over to Vic to stay with me to attend the Hanging Rock Car Show on 9th Feb. I have discussed my engines ideas with Panda on a couple of occasions and he has put me onto an engine builder he uses who also comes highly recommended as I was looking at the N/A 4G63 Twin Cam option.

Got a quote to get it N/A 4g63 Twin Cam built and bill came to about 10K and that's before I custom made headers and induction for it, would also need to inject it as I need run engine management for the timing so might as utilise it for fuelling as well.

2.6l 4g54 would be a little more cost effective and was originally what Panda suggested I do.

Cheers,

Andrew

[cheaterparts]

I know Panda (Peter) quite well, I will be seeing him in couple weeks when he comes over to Vic to stay with me to attend the Hanging Rock Car Show on 9th Feb. I have discussed my engines ideas with Panda on a couple of occasions and he has put me onto an engine builder he uses who also comes highly recommended as I was looking at the N/A 4G63 Twin Cam option.

Got a quote to get it N/A 4g63 Twin Cam built and bill came to about 10K and that's before I custom made headers and induction for it, would also need to inject it as I need run engine management for the timing so might as utilise it for fuelling as well.

2.6l 4g54 would be a little more cost effective and was originally what Panda suggested I do.

Cheers,

Andrew

First when you see Peter tell him I said hi - I haven't seen him for a few year he use to pop in when he was over at ether the V8 supa taxis on Phillip Island or the Grand Prix

Building an astron is was always quite cheap if you could do some stuff your self and the 2.6 can be made to run HP over quite a wide range
For example my own car with a NA 2.6 running around Sandown has done a 1min 28 using only 2 gears per lap
the tightest corner is dandenong corner which it will pull 3rd gear down around 2000 rpm and pulls realy well out of the corner
yet still pulls quite well right though past its top Hp 119.5 Kw atw @ 6100 and is pulling 7200 in forth at the end of the straight with a 3.89 diff

it use to cost me $ 1500 to build my engines in parts and to have a few machining jobs down outside

[A112H]

Would be a terrible shame if someone "confused" a 2.6lt block with w 2.0lt block when rebuilding.
Sometimes when facing the block you might accidentally clean the engine number off. Of course this would need to be re stamped, in this confusion you might mistakenly stamp a 2.0lt number on it.

... and that would be cheating, and the person would quite rightly be taken out the back an flogged ! .

Sorry

[Andrew77]

Hi Cheater,

If I could get 120kw atw that would be more than satisfactory, in fact that would be awesome!!!! That's double what I'm getting out of the current motor.

what's your recipe for a 2.6 that will achieve these numbers.

All going to plan I'm going to have the budget shortly to undertake this project.

Noticed on ebay a couple of off the shelf items such as competition light weight flywheel & billet H beam conrods. which may come in handy,

My plan would be:
Ported Head,
O/S valves,
good quality camshaft (any ideas???)
good quality conrods (as above)
Hi -comp pistons (customs built or flat tops???)
balanced, knife edged crank with lightened competition flywheel (as above)
twin 45 DOCE webers
Tuned length exhaust

any other suggestions?

As for clutch would one of the American Starion 4g54 turbo do the job and would it mate up to the standard galant box? What are you using?

[cheaterparts]

Hi Cheater,

If I could get 120kw atw that would be more than satisfactory, in fact that would be awesome!!!! That's double what I'm getting out of the current motor.

My plan would be:
Ported Head,
O/S valves, you can get 1 mm OS Stainless Steel inlet and exhaust that will cut straight into the std seats
good quality camshaft (any ideas???) the cam I use works quite well but my cam guy has pulled the pin it was a Speco grind - Wade cams also had almost the same grind and it was there second wildest radial grind
good quality conrods (as above) I still use the std rods just preped -polished , shot peaned balanced and ARP bolts
Hi -comp pistons (customs built or flat tops???) I use flat top duralights
balanced, knife edged crank with lightened competition flywheel (as above) I always prefured to make my own flywheels -- http://www.sigma-galant.com/viewtopic.p ... 148#p24148
twin 45 DOCE webers - with the 2.6 having big lungs you will need the biggest chokes you can get weber do a 40 mm choke off the shelf - I machined my own at 41 mm and thats as big as you can go on a 45 mm weber -
Tuned length exhaust - dont fit a muffler to close to your headers we found if a hotdog or muffler was fitted in front of the diff we lost a heap of power -

any other suggestions?

As for clutch would one of the American Starion 4g54 turbo do the job and would it mate up to the standard galant box? What are you using?
these are to big and heavy - my first clutch I had built at BGT in dandenong it was a puck clutch hand made with out any center springs
the presure plate was a 2 lt cover with a heavy diapham ( same diapham as a 1 tonne holden )
the cast presure plate did explode at sandown , that almost cut the bell housing right off the gearbox in one quick BANG

I have since made myself a flywheel that takes a 7 1/4" tilton race clutch - much lighter and wont expolde

Something to keep in mind there are other bits and pieces done and the engine had been developed over some time
allmost custom gear inside the engine I made myself