severly stumped 2tg/13t hybrid build

[sillycar chick]

Hey Jeffro,

Yeah I used stock 3TC pistons - got the whole engine from my dad, who had started it once since he had it, and he got it out of a car with only 10000K on it (this is before I was even born) so I would say its all stock gear. There is the possibility of the 2TG head I used being shaved at some stage before I got it, I dont know the history of the engine I got it off but it had blue gasket goo in certain places which indicated to me work had been done on it at some stage. But even if the head was shaved, I cant see it being all that much?

[TheToyman75]

Keep in mind not all 2TG heads have the same combustion chamber size

[sillycar chick]

Rod do you know which heads had different combustion chamber sizes?

My 88261 I measured at 62cc....
Im about to put on an 88220 head on 51LII, maybe I should be measuring it too before it goes on instead of assuming its going to be 62cc ( I know i should be doing this anyway )

[TheToyman75]

Dana,

I would definatly check the 88220 head. Being the first series head it more likely to have been shaved in the past reducing the chaamber size. The combustion chambers are supposed ot be slightly different in the 88220 but I was under the impression is was a slight shape variance not volume.

Why are you fitting the small valve head ??

[sillycar chick]

Dana,

I would definatly check the 88220 head. Being the first series head it more likely to have been shaved in the past reducing the chaamber size. The combustion chambers are supposed ot be slightly different in the 88220 but I was under the impression is was a slight shape variance not volume.

Why are you fitting the small valve head ??

Dad finally handed it over it has had a lot of porting work done, and the cams that are with it and set up to go are suspected to be a custom grind - but were not too sure. All the valve clearances on my head now are up to shit so I decided to swap heads instead of go through the pain of redoing the tappets Im confident swapping the head, that and i'd like to see what the inside of my engine is looking like after a year of being on the road

[Born-Enthusiast]

Ok, so im uploading photos of my engine build and placing them in the thread i started when i first began building this engine. I didn't want to flood the forums with too many threads just about my car and its problems . so if you want to have a look at the progress of building it give it a peep . I didn't take any of photo's of me actually putting it together just after all the stages so yeah hope you enjoy it. The thread is simply "2tg/3t hybrid"

[jeffro ra28]

I have a late model(didnt check casting) 2tg head. I cc'd the chamber tonight with a digital burret, it cc'd in at 62.5 and it has been surface ground. I dont know how much tho as it was done when i got the car.

I am sure the difference in volume between the heads has to do with the spark plug shrouding. The early stuff did not have any chamfer ("unshrouding") of the spark plug area. The later model heads had alot of unshrouding to give the spark plug a better chance of burning everything. I call it "give the spark plug a descent look at the chamber".

I noticed this with all the different 18rg heads i have/had.

The late model 88270 had the largest chamfer "unshrouding" around the spark plug. I am sure this is the case with the 2tg's aswell which would result in an estimated 2-4 cc's difference between models.

[thechuckster]

hopefully useful: did you guys replace the fuel filter and/or check the fuel pump? am assuming that the car sat for a while so maybe you ran out of fuel (and detonated) when you needed it to flow heaps.

[jeffro ra28]

Here are some specs for the 2/3 tg hybrid fans.

Please note this is my own personal engine im building and all these specs are after shaving the block .040" and modfying the piston dome shape for better flame travel.

Sorry about imperial measurements.

Cylinder bore: 3.385"
Stroke: 78mm
Chamber volume: 63cc
Piston crown to deck clearance: -.010" ( the squish area potrudes .010 above the block deck)
Compressed gasket thickness: .050"
Gasket bore diameter: 3.415
Piston dome volume: 19.386cc
Outside diameter of piston above top piston ring: 3.360 (this measurement is nessacary because this is the smallest part of the piston and alot smaller then the bore, so its important to calculate actuall static compression)
Measurement from crown(squish) to top of first piston ring: .235"

This works out to be.
Capacity 1811.486cc (110 cubes)
Compression ratio: 10.1123

May i add that all these measurements are extremely accurate using anually calibrated measuring equipment and a digital burret.

[TheToyman75]

May i add that all these measurements are extremely accurate using anually calibrated measuring equipment and a digital burret.

Mmmmmmm Digital Burret.... Now thats Just teasing !

[jeffro ra28]

Yeah, it was sitting in the cupboard for yonks until one day i did a cleanup. I said. "hey boss whats this?" Being as old fashioned as he is, he hadnt bothered to use it since he bought it.
Makes ccing a dream.

[Born-Enthusiast]

Yeah, it was sitting in the cupboard for yonks until one day i did a cleanup. I said. "hey boss whats this?" Being as old fashioned as he is, he hadnt bothered to use it since he bought it.
Makes ccing a dream.

how hard are those things to get a hold off and what do you rekon they cost these days

[jeffro ra28]

honestly no idea, try googling it.

All i know that it was bought from America when he visited there. It is a "brezizinski" (spelling) racing products one.

[Born-Enthusiast]

ok cheers mate

[oldcorollas]

50ml glass old fashioned non-digital Burettes are aroudn $30-40 each from lab supply places... i have one at home somewhere
good value methinks