is an 8 yr old boy required for chinuch to say krias shema in the morning on time? He gets upset when he doesnt and I told him he doesnt need to, is that right? Please send me sources.

ב"ה Mo'adim Lesimcha, First of all it is wonderful to hear that a child at this age is concerned with fulfilling the mitzvoth in their completeness. If he is ready he should also understand the meaning of Kriat Shema. In regard to your question, without getting into the overall guidelines to preparing children for mitzvoth, The Shulchan Aruch (או"ח סימן ע:ב) specifically discusses the mitzvah of Kriat Shema in regard to children. The Shulchan Aruch quotes Rabbenu Tam that says children are exempt from this mitzvah. The Mishna Brura(ס"ק ז) though says, that by "children" ,he means under the age of 6,however children 6-7 years old should already say Kriat Shema with the Berachot. However, see Piskei Teshuvot to (Shulchan Aruch((או"ח סימן ע:ב where he quotes other late authorities which bring of range of ages from 6-10 years all depending upon the development of the child. Furthermore, in the first edition (1965) of Shemirat Shabbat Kehichata,(pg. 314) where he dealt with the education of children to Mitzvot, he said that although it is a mitzvah to educate minors to recite krait Shema, the obligation doesn't require them to say it on time. The Bach on this Siman in Shulchan Aruch says that by age 12, the child should recite krait Shema according to all opinions. To summarize, it is highly praiseworthy that a child at this age wants to fulfill the mitzvah correctly. However, he should not feel bad if sometimes it doesn't work out, since there are those which exempt a child until age 10-11.(There are also different time limitations of saying Shema in the morning depending upon if you follow the opinion of the Magen Avraham or the Gr"a) According, to Rav Ben Tzion Abba Shaul,zt"l (אור לציון ח"ב פרק מ"ה אות יג, פסקי תשובות סי' ע הערה 11) if the child is still sleeping at Zman kriat Shema , one may rely on the opinion Rashi quoted in the Shulchan Aruch and he need not be waken as long as he has not reached age 12. All the best. May you have much Nachat from your child.