Mike's Early 70's Twin Cam Celica's

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71ta22
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Joined: May 21st, 2011, 10:34 am
Location: Carterton, New Zealand

Mike's Early 70's Twin Cam Celica's

Post by 71ta22 » June 1st, 2011, 11:53 am

I'm a new member on this site but have been visiting regularly over time.

Although I run Japanese cars I believe that their early twin cam's owed a lot to Italian engineering.

I thought It would be a good opportunity to share this with you all.

I own a couple of TA22 Toyota Celica's.

A 1971 1600 GT which is factory standard:
Front Side June 05.jpg
Front Side June 05.jpg (87.03 KiB) Viewed 4378 times
Engine Bay Vertical May 06.jpg
Engine Bay Vertical May 06.jpg (89.51 KiB) Viewed 4378 times
Engine specs:
1588cc
Pistons are 9.8:1 C/R
Cams are 248 advertised duration with 9.5mm net lift.
Valves are Intake 43mm, Exhaust 37mm with single spring and shim under bucket.
Carbs are 40PHH Mikuni Solex with 30mm chokes, 125 mains and 150 air jetting.

Car runs well although the engine has done nearly 300,000km with 1 rebuild following blown head gasket.

A 1973 1600 GT which basically has had a TE71 Corolla's running gear transplanted in plus the engine stroked:
Side view.jpg
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Plug leads and throttle cable(01).jpg
Plug leads and throttle cable(01).jpg (234.28 KiB) Viewed 4378 times
Engine specs:
1770cc
Crank, pistons and con rods from a 3T engine for 10.5:1 C/R
Head ported and port matched but not polished. Intake manifold ported.
Cams are 292 advertised duration with 10.9mm net lift.
Valves are Intake 44.5mm, Exhaust 38.5mm with twin spring and shim under bucket.
Carbs are 45 Weber's with 34mm chokes, 135 mains and 180 air jetting.

This car is a completely diferent animal. Has good torque from 3,500rpm and pulls hard up to 7,500 rpm beyond which standard factory connecting rods are likely to give way.

I look forward to your comments.
Last edited by 71ta22 on January 28th, 2012, 9:55 am, edited 2 times in total.
Mike
71TA22

TomLouwrier
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Re: Mike's Early 70's Twin Cam Celica's

Post by TomLouwrier » June 8th, 2011, 9:59 pm

Hi Mike,

Welcome to the group!
Nice to see your two rides. There are not many left from that period, let alone in such a condition.
I never had much with Japanese gear personally, but looking back these do have a special character and the styling is quite aggressive.

Must be a lot of fun working on them and having a good blast. As much fun as a Fiat.
I know they are DOHC, but are these the ones with the early 16v engines? Take good care of them.

regards
Tom
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robert kenney
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Re: Mike's Early 70's Twin Cam Celica's

Post by robert kenney » June 9th, 2011, 3:57 am

Very nice Yotas, I had a 71 Celica, originally had the 18r but got a 18rg twin cam as time went on. Very fun and fast. I have also had a 1981 Celica that I massaged with a 20r head ported by the TRD GTP master, 10.5-1 Weisco pistons custom rods headers and dual side draft Mikuni 40s. My current daily driver is a 1985 Celica. Great little cars.
Thanks for sharing.
Tom what I remember is that these twin cams of the period were 8V like the 18rg.
Robert Kenney # 111

71ta22
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Joined: May 21st, 2011, 10:34 am
Location: Carterton, New Zealand

Re: Mike's Early 70's Twin Cam Celica's

Post by 71ta22 » June 12th, 2011, 6:37 am

TomLouwrier wrote: Must be a lot of fun working on them and having a good blast. As much fun as a Fiat.
I know they are DOHC, but are these the ones with the early 16v engines? Take good care of them.
Hi Tom,

Engines are 8v.

These are good engines to work on. Only real issue with them is weight as the bottom end is a big lump of cast iron. On the flip side of the coin they share bottom end parts with 2T and 3T engines so upgrade parts are available and relatively cheap.

Have just got some new weber 45 DCOE 9's so will put them on and see how things go.
Mike
71TA22

71ta22
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Joined: May 21st, 2011, 10:34 am
Location: Carterton, New Zealand

Re: Mike's Early 70's Twin Cam Celica's

Post by 71ta22 » January 28th, 2012, 10:53 am

It's a while since I last posted.

I installed a pair of weber 45 DCOE 9's. At the same time I had a set of cams ground to a Kent L14 spec. These have been shimmed and run in.

Here's what the head looks like with the cam cover off. Other than the shim under bucket set up these engines are very easy to work on.
Cylinder head internals(01).jpg
Cylinder head internals(01).jpg (244.98 KiB) Viewed 4378 times
I have set the cams up with adjustable cam gear. This makes cam timing changes very simple and repeatable. 2 degrees of advance on the inlet cam in the photo below.
Adjustable cam gear(01).jpg
Adjustable cam gear(01).jpg (225.6 KiB) Viewed 4378 times
Cams for these engines come with slots so you can quickly get them timed to factory specs. These are interference engines so my $1 home made cam lock tool ensures everything is lined up correctly while tightening up the cam gears.
Cam lock in use(01).jpg
Cam lock in use(01).jpg (226.86 KiB) Viewed 4378 times
Guy will probably not be impressed but I like socks on the end of the carb ram tubes. I would have real difficulty getting anything else to work with the standard brake master cylinder location.
Carbs and socks(01).jpg
Carbs and socks(01).jpg (248.49 KiB) Viewed 4378 times
Mike
71TA22

Guy Croft
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Re: Mike's Early 70's Twin Cam Celica's

Post by Guy Croft » January 28th, 2012, 12:32 pm

L14 regrinds on an 8V.

I shall be interested to hear what that does to the torque curve.

G

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Re: Mike's Early 70's Twin Cam Celica's

Post by NineOneSix » January 28th, 2012, 7:22 pm

Stunning! When Toyota had real style, amazing work.

4v6
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Re: Mike's Early 70's Twin Cam Celica's

Post by 4v6 » January 29th, 2012, 6:32 pm

I have a real soft spot for these early Toyota's, hope its more fulfilling to drive than my current daily (a 94 corolla).
Im not compalining about it, its just a little bland, unlike your beautiful example there.
Tony Warren. GC #96.

71ta22
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Joined: May 21st, 2011, 10:34 am
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Re: Mike's Early 70's Twin Cam Celica's

Post by 71ta22 » January 30th, 2012, 6:43 am

Thanks everyone for your kind words.

L14 cam grind was originally for the lotus 1588 8v engine so appropriate for the period. Torque is measured through the cars seat but this cam comes in at 2.5k rpm and keeps going up to 7.5k rpm. I'm still using factory rods with factory red line at 7k rpm so dont want to push too far. This is quite good as the cam spec is for 2.5k to 6.5k rpm. I think the Weber 45's help the top end. I really should get a good set of connecting rods!!!!!!

As a point of interest has anyone on this board run Kent L1 intake and L14 exhaust cams in combination? Toyota Racing Development recomended 304 duration intake and 272 or 288 duration exhaust cams for these engines back in the day. This would be a close match.

Some more technical pictures. Sorry if quality is not that good.

Valve train was quite good for a car that cost less than a 2 litre Capri back in the day. It did not have the hatchback of course.
Inlet valve train(01).jpg
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Combustion chamber.
Chamber(01).jpg
Chamber(01).jpg (159.68 KiB) Viewed 4336 times
Inlet Valve seat cuts were 30/45/65 degrees from the factory.
Inlet(01).jpg
Inlet(01).jpg (148.85 KiB) Viewed 4336 times
Inlet and exhaust valves. 8mm stem - 44.5mm diameter inlet and 38.5mm exhaust.
Valves from side(01).jpg
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Valves(01).jpg
Valves(01).jpg (136.49 KiB) Viewed 4336 times
Inlet valve head surfaced at 44.5 degrees and lapped.
Inlet valve(01).jpg
Inlet valve(01).jpg (99.43 KiB) Viewed 4336 times
Mike
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Guy Croft
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Re: Mike's Early 70's Twin Cam Celica's

Post by Guy Croft » January 30th, 2012, 9:10 am

If the L14 grind is onto blanks it might work OK, if it's a regrind onto OE cams maybe not. Whether you get any gain from regrinding like that depends on the shape of the cam before you start. On the 8V Fiat TC for example it is a disaster.

G

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