Lancia Beta Forum
August 15, 2022, 02:20:52 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Beta Meeta 50th Anniversary 2022 Bookings now open
https://www.betaboyz.myzen.co.uk/forum/index.php?topic=4385.0
 
   Home   Help Contact Admin Search Calendar Gallery Articles Login Register  
Pages: [1] 2
  Print  
Author Topic: Guy Croft race engine build  (Read 31010 times)
0 Members and 1 Guest are viewing this topic.
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« on: May 09, 2014, 12:33:09 PM »

Dear All,

Though I would post a few pics of my GC full race engine build. I built the bottom end, whilst Mr Croft modified/built the head and fitted the cams.

Spec:

2 litre 85mm bore, 2043cc, GC forged 11:1 pistons.
GC Forged race con rods.
GC Steel flywheel, 6 puck clutch
modified sump, VX oil pump
VX head, 43.5/36mm valves modified to full race spec
GC 4A race inlet cam with 11.8mm lift
GC 3D exhaust cam with 10.9mm lift
Twin 45 DCOE carbs with 40mm chokes on GC inlet
4-1, 1 5/8" bore header with 36" primaries
2 1/4" exhaust with single straight through muffler
Davies Craig electric water pump
MSD 6A multi spark capacitive discharge ignition
NGK B9EGV plugs
19 row oil cooler with remote filter, oil thermostat and Accusump
For Focus ST170 radiator
Daihatsu Charade alternator with toothed belt drive

PREDICTED POWER OUTPUT: 190BHP/154lb ft torque.
REV LIMIT: 9000RPM (although GC said it would be safe to 9500!!)



* GC block IOH painted.JPG (291.96 KB, 980x735 - viewed 8624 times.)

* GC IOH head.JPG (201.78 KB, 800x600 - viewed 7715 times.)

* IMG_4612.JPG (135.69 KB, 640x480 - viewed 7187 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #1 on: May 09, 2014, 12:37:57 PM »

Race rods & piston only 1kg, compared to OE which were 1.43kg ! The weight difference equates to leaving 1 complete OE piston & rod out! This important as the reciprocating mass needs to be less when revving to 9000rpm!


* Gc vs std piston & rod (1).JPG (209.42 KB, 735x980 - viewed 7220 times.)

* Gc vs std piston & rod (2).JPG (198.76 KB, 735x980 - viewed 6943 times.)

* Gc vs std piston & rod (3).JPG (232.18 KB, 980x735 - viewed 7055 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #2 on: May 09, 2014, 12:51:12 PM »

Setting ring gaps and fitting pistons to rods. The rings are CP race type and are very thin compared to OE type. They also have very low spring tension, meaning less friction on cylinder walls. it doesn't mean they don't seal well!


* GC piston & rings (2).JPG (238.71 KB, 735x980 - viewed 6808 times.)

* fitting rings GC A8 piston (2).JPG (203.7 KB, 735x980 - viewed 6927 times.)

* fitting rings GC A8 piston (1).JPG (201.14 KB, 735x980 - viewed 7209 times.)
Logged
HFStuart
Legendary Member
******
Offline Offline

United Kingdom United Kingdom

Posts: 1840



« Reply #3 on: May 09, 2014, 03:28:26 PM »

Ahh, engine porn!

That must have cost a pretty penny - but then the quality of Guy's work is beyond reporach so if he predicts 190bhp that's that it will make.

When I've saved a few pennies and got bored of my 'only' 150bhp I will be buying some of those HC pistons myself!
Logged
Hawk
Hero Member
*****
Offline Offline

England England

Posts: 448



« Reply #4 on: May 12, 2014, 07:14:53 AM »

naked engine - phwoar Smiley

that's a good saving on the rods and pistons - have you had the crank balanced?
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #5 on: May 12, 2014, 07:47:33 AM »

Hawk - yes crank, front pulley, flywheel (including clutch pressure plate) all balanced together.

Stuart - Don't ask about cost, but not as much as you would imagine. At the end of the day this engine will have been completely built for less than 5 grand (GBP)including ancilliaries. I did ALL the bottom end work myself though, as shipping a block and then complete engine back and forth from GB to Oz would have been as much again.....

As it happens I was lucky and managed to buy a nice useable VX head off Matt, a forum member, Thanks Matt!! Why a VX head? Well it has the nice big 36mm parallel throat inlet ports and 43.5mm inlet valves as standard, very similar to the Fiat 130TC head, so this means the cost of modification is less then with a standard Beta head with 42mm inlets

Now on with the story and next up some pics of the assembled block. I have built plenty of twin cam engines, but when you are playing with expensive parts you start questioning your own ability to do the job in case you stuff something up! In particular fitting pistons to rods with those horrible wire pin retainers, and gapping/fitting fragile piston rings, as you know it will cost.....

I did a "dry build" check, using an old head gasket I fitted the head and fitted cam belt, and turned it over two complete inlet/exhaust cycles to check valve to piston clearance at TDC. The cams in this engine have over 4.5mm lift at TDC compared to standard Beta that has less than 2mm...


* GC 12.260 Crank_rods assmbled (1).JPG (202.2 KB, 855x570 - viewed 6640 times.)

* dry build checks IOH (1).JPG (151.21 KB, 717x538 - viewed 6757 times.)

* GC12.260 ready for head (1).JPG (125.48 KB, 653x490 - viewed 7162 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #6 on: May 12, 2014, 08:03:24 AM »

Good job I took the strainer off the oil pump....Otherwise my big ends would have not looked like they do below. I fitted the big ends and did a few rotations to check all was good and then took the cap off again on No.1 cylinder to check...


* GC12.260 oil pump overhaul (1).JPG (135.49 KB, 490x653 - viewed 6517 times.)

* GC12.260 oil pump overhaul (3).JPG (101.12 KB, 653x490 - viewed 6839 times.)

* GC 12.260 big ends (2).JPG (122.4 KB, 653x490 - viewed 6594 times.)
Logged
Hawk
Hero Member
*****
Offline Offline

England England

Posts: 448



« Reply #7 on: May 12, 2014, 08:30:06 AM »

Keep the pics and info coming Smiley

I would love to drive a 190bhp Beta. 
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #8 on: May 12, 2014, 08:30:42 AM »

An uprated clutch and baffled sump finish the bottom end..."True TDC" marked on flywheel so ignition timing can be checked from gearbox inspection hole.


* Beta sump mods (2).JPG (161.16 KB, 570x855 - viewed 6925 times.)

* GC 12.260 clutch & flywheel (1).JPG (222.63 KB, 538x717 - viewed 6918 times.)

* GC 12.260 clutch & flywheel (4).JPG (149.89 KB, 717x538 - viewed 6688 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #9 on: May 12, 2014, 08:39:11 AM »

Head finally goes on with uprated GC head gasket and bolts, cam belt on cams timed ...


* GC head bolts (2).JPG (70.17 KB, 490x653 - viewed 6342 times.)

* GC 12.260 head on block.JPG (136.11 KB, 490x653 - viewed 7057 times.)

* GC12.260 cam timing exhaust.JPG (104.16 KB, 653x490 - viewed 7277 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #10 on: May 12, 2014, 08:48:21 AM »

I decided to use an electric water pump instead of the original as this is supposed to free up a few BHP at high rpm, so had to make up an adapter plate to fit a water outlet.


* Electric water pump.JPG (154.39 KB, 490x653 - viewed 6413 times.)

* water pump blanking plate (1).JPG (109.08 KB, 490x653 - viewed 6522 times.)

* water pump blanking plate (4).JPG (168.29 KB, 490x653 - viewed 7480 times.)
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #11 on: May 12, 2014, 09:01:39 AM »

A view down inlet port with piston at TDC and valves on the "overlap". You can literally see straight through the inlet port into the exhaust port with these cams! It is this that gives the "cross scavenge" effect at higher rpm which helps draw charge in through the inlet tract so long as the exhaust system is tuned to match...


* GC12.260 inlet port & overlap (1).JPG (109.05 KB, 735x735 - viewed 6354 times.)

* GC12.260 inlet port & overlap (2).JPG (86.37 KB, 490x490 - viewed 6571 times.)
Logged
HFStuart
Legendary Member
******
Offline Offline

United Kingdom United Kingdom

Posts: 1840



« Reply #12 on: May 12, 2014, 02:49:24 PM »

Great posts and a clever mod with the pump housing - I've thought of one of those EWP setups myself - I think the Emerald ECU could control it too-  but mine has little trouble with temperature anyway so it not urgent but let us know how you get on with it.

5k seems pretty good value for that output

I'm familiar with the buy a VX head route from a forum member to get big valves- in my case thanks Eric  Wink
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #13 on: May 12, 2014, 08:37:00 PM »

One advantage with the EWP is that it will run on after shutdown to prevent heat soak, they make bold claims about it saving up to 8 BHP, however this was on a V8 motor, so if I gain a couple of BHP I will be happy.😊.

Wished I could fuel inject this engine, I'm sure it would then pass that double century mark....Historic racing rules  mean carbs it is, and for setup makes life a little easier.
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #14 on: June 13, 2014, 12:56:54 PM »

To go with the engine I built a new 4-1 exhaust manifold
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #15 on: June 13, 2014, 01:00:36 PM »

Engine in car
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #16 on: June 13, 2014, 01:07:18 PM »

Preliminary dyno run produced 155BHP at wheels in 4th gear which translates to 188BHP at flywheel. Dyno sheet went only to 7500RPM, but engine holds power to nearly 8000RPM before starting to drop off...

Still some fine tuning to do and revised Pipercross air filter to be fitted....Will post more dyno results soon, but pretty happy with result so far!
Logged
75coupe
Hero Member
*****
Offline Offline

Posts: 298

1975 Beta coupe 2L


« Reply #17 on: June 13, 2014, 01:17:16 PM »

Turn the volume up for this one, flat out 4th gear at Lakeside raceway...

http://youtu.be/YHD5nUp5gAM

A few laps of the same short 2.4km circuit. Had a few issues changing gear due to the gear oil used with the LSD, which meant he synchro wouldn't work once hot, hence the missed gears a few times....rectified now waiting for next track outing...

http://youtu.be/BPOxb3nsFaA
Logged
lbcoupe76
Sr. Member
****
Offline Offline

Australia Australia

Posts: 149



« Reply #18 on: June 13, 2014, 02:29:55 PM »

Yeah baby, that's awesome. Grin
Logged

1976 Beta coupe 1800 "Kermette"
1975 Beta coupe 1800 x 2
1974 Beta Berlina 1800
1989 Thema i.e turbo
1988 Thema i.e turbo
Fiat 1500



Smoke me a Kipper i'll be back for breakfast
swedgamma
Jr. Member
**
Offline Offline

Posts: 36


« Reply #19 on: June 13, 2014, 07:38:33 PM »

What a fantastic sound,especially the fly-by noice!!And the engine didnt miss a beat either,Congratulations!

Urban(Swedgamma)
Logged
Pages: [1] 2
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
SMFAds for Free Forums
Valid XHTML 1.0! Valid CSS!